*********A*********
By Authority Of
THE UNITED STATES OF AMERICA
Legally Binding Document
By the Authority Vested By Part 5 of the United States Code § 552(a) and
Part 1 of the Code of Regulations § 51 the attached document has been duly
INCORPORATED BY REFERENCE and shall be considered legally
binding upon all citizens and residents of the United States of America.
HEED THIS NOTICE : Criminal penalties may apply for noncompliance.
Document Name: ANSI B7.1-1970: Safety Code for the Use, Care, and
Protection of Abrasive Wheels.
CFR Section(s): 29 CFR 1926.57, 1926.303(c) and (d)
Date of Action: 44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979
#it.9-0J
A
*- : i
•:^Hii\iti;\
American National Standard
safety code for
SUPERSEDED
- -= 13^, Reproduced By GLOBAL "\
=gs ENGINEERING DOCUMENTS
==- i? With The Permission Of ANSI
-=-~ Under Royalty Agreement
the use, care, and protection
of abrasive wheels
c
American Notional Standard
An American National Standard implies a consensus of those substan-
tially concerned with its scope and provisions. An. American National^ ss-rj^^f ,G?, fi'' : ^ -9
Standard is intended as a guide to aid the manufacturer, the consumer.fo^atfkJ^" 1 .^^
and the general public. The existence of an American National Standard
does not in any respect preclude anyone, whether_he has approved the
standard or not, from manufacturing, marketing,: purchasing, or using
products, processes, or procedures not conforming to the standard. Amer-
ican National Standards are subject to periodic review and users are cau-
tioned to obtain the latest editions.
CAUTION NOTICE: This American National Standard may be revised
or withdrawn at any time. The procedures of the American National
Standards Institute require that action be taken to reaffirm, revise, or with-
draw this standard no later than five years from the date of publication.
Purchasers of American National Standards may receive current infor-
mation on all standards by calling or writing the American National
Standards Institute.
DATES OF PREVIOUS REVISIONS
Originally ieeued ae a Tentative American Standard in 19tt.
Revised and ieeued at an American Standard in 19X6.
Reviled *» 1930, 19SS, I9i3, 19X7, 1956, 196* and 1970.
Copyright 1970 by the American National Standards Instigate. 7.™
2831 *~ 9
CONTENTS
SECTION 1— SCOPE AND DEFINITIONS Page
LI Scope 1
12 Definitions
1.2.1 Shall and Should
122. Abrasive Wheel
1.2.8 Organic Bonded Wheels
1.2.4 Inorganic Bonded Wheels
1.2.5 Reinforced Wheels 2
1.2.6 Grinding Surface or Face 2
12.1 . SafetyGuard 2
1J2.8 Wheel Speed 3
123 Revolutions Per Minute 2
1.2.10 Surface Feet Per Minute S
1.2.11 Flanges 3
1.2.12 Steel Rings 3
1.2.13 Threaded Bushings 4
1.2.14 Reducing Bushings 4
1.2.15 Tape or Wire Winding 4
1.2.16 Chuck 4
1.2.17 The Wheel Manufacturer 4
1.2.18 The Machine Builder 6
1.2.19 The User of Wheels and Machines 5
1.3 Usage Definitions 5
1.3.1 Centerless O.D. Grinding 5
1J&2 Coping .• 5
1.3.3 Cutting Off 6
1.3.4 Cylindrical O.D. Grinding 6
1.3.5 Internal Grinding 6
1.3.6 Off-Hand Grinding 6
12.1 Portable Grinding 6
1.3.8 Precision Grinding 6
1.8.9 Saw Gumming 7
1.3.10 Slotting 7
1.3.11 Snagging 7
1.3.12 Surface Grinding 7
1.3.13 Tool Grinding 7
1.3.14 Tuck Pointing 7
1.4 Definitions and Limitations of Wheel Shapes 7
1.4.1 Type 1 Straight Wheels 8
1.4.2 Type 2 Cylinder Wheels 8
1.4.3 Abrasive Disc Wheels 8
1.4.4 Type 4 Taper Sided Wheels 8
1.4.5 Type 6 Recessed One Side Wheels 9
1.4.6 Type 6 Straight Cup Wheels 9
1.4.7 Type 7 Double Recessed Wheels 9
1.4.8 Type 11 Flaring Cup Wheels 10
1.4.9 Type 12 Dish Wheels 10
1.4.10 Type 13 Saucer Wheels 10
1.4.11 Types 16. 17, 18, 18R and 19 Cone and Plug Wheels 11
1.4.12 Types 20, 21, 22, 23, 24, 25, 26 Relieved and/or Recessed Wheels 12
1.4.13 Types 27 and 28 Deoressed Center Wheels 13
1.4.14 Type 27A Depressed Center Wheels 13
1.4.15 Cutting Off Wheels 14
1.4.16 Coping Wheels 14
1.4.17 Tuck Pointing Wheels 14
1.4.18 Mounted Wheels 15
1.4.19 Threaded Hole Cup Wheels , 15
1.4.20 Modified Types 6 & 11 Wheels (Terrawo) 15
SECTION 2— HANDLING, STORAGE AND INSPECTION
2.1 Handling 16
22 Storage 16
2.8 Inspection 18
SECTION 3— GENERAL MACHINE CONDITIONS
3.1 Machine Design and Maintenance 20
8.2 Safety Guards 20
8.3 Power 20
3.4 Exhaust Provision 20
3.5 Diameter of Spindle , 21
8.6 Flanges 21
8.7 Work Rests 21
8.8 Limiting Wheel Diameter 21
S3 Direction of Machine Spindle Thread 23
8.10 Length of Machine Spindle Thread 23
2832 A- 10
CONTENTS (Continued)
Page
3.11 Site of Spindle or Mount 24
8.12 Threaded Hole Wheels 24
3.13 Mounting of Abrasive Discs
(Inserted Nut, Inserted Washer and Projecting Stud Type) 25
8.14 Mounting of Plate Mounted Type Wheels -26
SECTION 4— SAFETY GUARDS
4.1 General Requirements 27
43 Cup Wheels 27
4.3 Guard Exposure Angles- 28
4.3.1 Bench and Floor Stands 28
4.3.2 Cylindrical Grinders 29
4.3.3 Surface Grinders and Cutting-off Machines 29
4.3.4 Swing Frame Grinders 29
4.3.5 Automatic Snagging Machines 30
4.3.6 Top Grinding SO
4.3.7 Portable Grinders 30
43.7.1 Right Angle Head or Verticle Portable Grinders— Type 27 and 28 Wheel SO
43.73 OtEer Portable Grinders 30
4.4 Exposure Adjustment 31
4.5 Enclosure Requirement 32
4.6.1 Safety Guard 32
4.53 Additional Enclosure 32
4.6 Material Requirements and Minimum Dimensions 33
4.6.1 For Speeds Up to 8,000 S.F.P.M 33
4.6.2 For Speeds Up to 16,000 S.F.P.M 33
4.6.3 Optional Materials 33
4.6.4 Exceptions 33
4.7 Material Specifications 34
4.8 Construction Guide for Fabricated Guards 34
4.9 Specifications for Rivets, Bolts, Welds and Studs for Fabricated Guards 34
4.10 Construction Guide for Drawn Steel Guards .-* 37
4.11 Band Type Guards — General Specifications 40
4.12 Construction Guide for Band Type Guards 40
SECTION 5— FLANGES
5.1 General Requirements 42
5.1.1 Type 1 Cutting-Off Wheels 42
5.13 Type 27A Cutting-Off Wheels 42
5.13 Flange Types 43
5.2 Design and Material 43
6.3 Finish and Balance 43
5.4 Uniformity of Diameter ; 43
5.5 Recess and Undercut 44
6.6 Contact 44
5.7 Driving Flange 45
6.7.1 Flanges, Multiple Wheel Mounting 45
6.8 Dimensions 45
6.8.1 Straight Flanges, Relieved and Unrelieved " . 45
6.8.2 Straight Adaptor Flanges Heavy Duty Grinding 45
6.83 Sleeve Flanges 46
63 Repairs and Maintenance 4C
SECTION 6— MOUOTTNG
6.1 Inspection 52
63 Arbor Size j 62
63 Surface Condition 52
6.4 Bushing 52
6.5 Blotters j. S3
6.6 Flanges 53
6.7 Multiple Wheel Mounting 53
H
2833 A_l1
CONTENTS (Continued)
Page
6.8 Tightening of the Mounting Nut 54
6.8.1 Single End Nut 64
6.8.2 Multiple Screws 64
65 Direction and Length of Thread on Machine Spindle 64
6.10 Threaded Hole Wheels 64
6.11 Mounting of Abrasire Discs
(Inserted Nut, Inserted Washer and Projecting Stud Type) 65
6.12 Mounting of Plate Mounted Type Wheels 65
6.18 Safety Guards 65
6.14 Mounted Wheels 65
6.15 Type 27 and Type 28 Wheels 66
6.16 Type 27A Wheels 66
6.17 Type 2 Cylinder Wheels 67
6.18 Segments 57
SECTION 7— SPEEDS
7.1 Standard Speeds 58
7.1.1 Standard Maximum Speeds 58
7.1.2 Machine Builder's Responsibility 68
7.1.8 Wheel User's Responsibility 58
7.1.4 Wheel Manufacturer's Responsibility 60
7.2 Speed Check of Machines — User's Responsibility 61
7.3 Speed Adjustment Control — User's Responsibility 61
SECTION 8— SPECIAL SPEEDS
8.1 Introduction 62
8.2 Requirements for Special Speeds '62.
8.2.1 Condition A — The Wheel Manufacturer 62
8.2.2 Condition B — The Machine Builder 63
8.2.3 Condition C — The User 63
8.3 Wheel Manufacturer's Responsibility 63
8.3.1 Manufacturer's Test 63
8.3.2 Identification , 63
8.4 Machine Builder's Responsibility 63
8.4.1 Genera] Machine Conditions 64
8.4.2 Safety Guards 64
8.4.3 Flanges 64
8.5 User Responsibility 64
8.5.1 Handling. Storage and Inspection 65
8.5.2 General Machine Conditions 65
8.5.3 Safety Guards 65
8.5.4 Flanges 65
8.5.5 Mounting 65
8.6.6 General Operating Rules 65
SECTION 9— GENERAL OPERATING RULES
9.1 User's Responsibility 66
9.2 Investigation .After Breakage 66
9.3 Wheel Speed >. 66
9.4 Replacing Safety Guard 66
9.5 Starting the Wheel 66
9.6 Balance 66
9.7 Trninir and Dressing ...>. 67
9.8 Wet Grinding 67
9.9 Side Grinding 67
9.10 Lubrication 67
9.11 Check for Wear , 68
9.12 Work Rests 1 68
9.13 Large Hole Inorganic Bonded Wheels 68
SECTION 10— MOUNTED WHEELS ' \
10.1 Maximum Safe Operating Speed . 69
10.2 Special Maximum Operating Speed ..'. 70
10.3 Work Pressure 70
TABLES OF MAXTMUM OPERATING SPEEDS FOR MOUNTED WHEELS 71-85
CONVERSION TABLE— WHEEL SPEEDS (SFPM) 86
APPENDIX A 87
KEYWORD TNDEZ 88
ui
283* A- 12
FOREWORD
(This Foreword is not a part of the American National Standard Safety Code
For the Use, Care and Protection of Abrasive Wheels, B7.1-1970)
In 1917 the Grinding Wheel Manufacturers and the Machine Tool Builders began to recog-
nize a need for codification and standardization of the basic requirements of safe operation of
abrasive grinding wheels. By 1922 these two groups had completed a tentative draft of require-
ments for an American Standard. It was reviewed, revised, and subsequently published in 1926
under the auspices of the American Standards Association (now the American National Standards
Institute) as the "American Standard Safety Code For the Use, Care and Protection of Abrasive
Wheels." The Code has been revised in 1930, 1935, 1943, 1947, 1956, 1964 and 1970.
The two groups which initiated the Code in 1917 have been expanded into a Standards Com-
mittee representing nationally recognized engineering, safety, abrasive wheel and grinding ma-
chine fabricators and user associations, labor organizations, insurance underwriter groups, and
several interested government agencies.
Safety is indeed everybody's business in the "Use, Care and Protection of Abrasive Wheels."
Basic to a proper understanding of the Code is a thorough knowledge of the nature and char-
acteristics of abrasive wheels and the grinding machines on which they are used. Their safety
and protection devices can and must be used to limit, if not eliminate, injury or damage in case
of accidental wheel breakage. Constant educational programs at all levels are the best insurance
against those unforseen conditions or circumstances which result in an industrial accident.
This Code outlines the best known practices, tests, and safety devices for the protection
of all personnel and equipment from injury or damage in case of accidental wheel breakage.
USE THEM.
This, the "American National Standards Institute Safety Code For the Use, Care and Pro-
tection of Abrasive Wheels," is specifically dedicated to vigilant safety practice and education.
to
2«J5 A _ l3
STANDARDS COMMITTEE
Members who compose the Standards Committee and the organizations they represent are as follows:
STANLEY W. GERNER, Chairman
National Bureau of Standards
ALLEN P. WHERRY, Secretary
Grinding Wheel Institute
Organization Represented
Name and Business Affiliation
American Federation of Labor A Congress of
Industrial Organizations
American Foundrymen's Society
American Insurance Association
American Iron & Steel Institute
American Mutual Insurance Alliance
American Society of Mechanical Engineers
American Society of Safety Engineers
Compressed Air & Gas Institute
Department of Health, Education and Welfare
Public Health Service ....
Grinding Wheel Institute ....
Industrial Safety Equipment Association, Inc.
International Association of Governmental
Labor Officials
National Bureau of Standards, U. S.
Department of Commerce
National Machine Tool Builders Association
National Metal Trades Association . : .
National Safety Council ....
Power Tool Institute, Inc. .
TJ. S. Department of Labor
Charles F. West, Jr., International Association of
Machinists
Herbert J. Weber
Lee Murphy, Employers-Commercial Union
Companies
R. G. Dettmar, Interlake Steel Corporation
Joseph W. Hart, Liberty Mutual Insurance Co.
Frederick H- Deeg (Alt.)
H. J. Eierman, Royal Globe Insurance Cos.
H. Stanley Tabor, American Mutual Insurance
Companies
W. B. Fleischer, Air Tool Div., Dresser Industries,
Inc.
R. H. Oatley (Alt.), Stanley Air Tools Div. of
The Stanley Works
Jeremiah R. Lynch
J. R. Gregor,_ General Grinding Wheel Corp.
J. C. Arndt, Simonds Abrasive Div., Wallace-Murray
Corp.
G. R. Blake. Norton Company
Norman Kendall, Cortland Div., American Abrasive
Corp.
W. G. Pinkstone, A. P. de Sanno & Son, Inc.
A. A. Russ, National Grinding Wheel Div., Federal-
Mogul Corp.
R. A. Beebe (Alt.), Acme Abrasive Company
R. J. Gandy, Jr. (Alt.), The Carborundum Co.
R. O. Lane (Alt.), Abrasives Div., The Bendix Corp.
E. G. Rieker (Alt.), Precision Grinding Wheel Co.,
Inc.
L. C. Seelye (Alt.), Avco Bay State Abrasives Div.
John I. Junkin, Junkin Safety Appliance Co., Inc.
Charles N. Sumwalt, Jr. (Alt.)
Frank W. Marcaccio, Div. of Industrial Inspection,
Rhode Island Dept. of Labor
Harold C. Barringer, Maryland Dept. of Labor and
Industry
William Dailey (Alt.), Rhode Island Dept. of Labor
James A. Underwood (Alt.), Colorado Industrial
Commission
Stanley W. Gerner
Harold S. Sixer, Brown & Sharpe Mfg. Co.
W. Atkinson. Jr. (Alt), NMTBA
Emile Couture, Brown & Sharpe Mfg. Co.
E. O. Kumier, TRW Inc.
Joseph VanSickle {Alt.)
J. L. Bennett, The B'ack & Decker Mfg. Co.
Peter Rebechini (Alt), SW«! C~— .
Stanley J. Butcher, Bureau of Labor Standards
James M. Meagher, Jr. (Alt.)
28 36
A- 14
EXPLANATION OF CODE FORMAT
This 1970 revision of the B7 Safety Code continues the two-col-
umn format to provide supporting information for the regulations.
The material in the left column is confined to code regulations
only and is so captioned. These regulations are printed in distinc-
tive bold type to indicate their authority without question. Where
a condensed document is required (e.g. for State Code adoption),
the material in the left column together with supporting tables
and sketches can be used as a complete code.
The right column, captioned "Explanatory Information," offers
basic reasons for each rule to encourage compliance. Material ap-
pears in this second column only when it clarifies the regulation.
This column should not be construed as being a part of the American
National Standard Safety Code For The Use, Care And Protection
of Abrasive Wheels B7.1-1970.
Operating rules (safe practices) are not included in either col-
umn of this Safety Code unless they are of such nature as to be
vital safety requirements, equal in weight to other requirements
included in the Code.
2837
8-1
CODE REGULATIONS
Section 1
SCOPE AND DEFINITIONS
1.1 Scope
This code sets forth rules and specifications
for safety in the use of abrasive wheels, ex-
cluding natural sandstone, including specifica-
tions for safety guards, flanges, chucks and
rules for the proper storage, handling, mount-
ing and use of grinding wheels.
Metal, wooden, cloth or paper discs, having a
layer of abrasive on the surface, are not in-
cluded.
Explanatory Information
(NOT FART OF ANSI CODE)
Section 1
Scope and Definitions
1.1 Scope
This column will offer reasons for the rule, to
encourage compliance. Material will appear in
this column only when it will clarify the reg-
ulations. (Not including tables or sketches.)
1.2 Definitions
1.2.1 SHALL AND SHOULD
The word "shall" where used is to be under-
stood as mandatory and "should" as advisory.
1.2 Definitions
The sketches and photographs used in this
publication are classified as "Figures" or "Illus-
trations." The items listed as "Figures" are
applicable to the code regulations, while those
listed as "Illustrations" apply to the explana-
tory information.
1.2.2 ABRASIVE WHEEL
An abrasive wheel is a cutting tool consisting
of abrasive grains held together by organic or
inorganic bonds. Diamond and reinforced
wheels are included.
1.2.2 ABRASIVE WHEEL
1.2.3 ORGANIC BONDED WHEELS
Organic wheels are wheels which are bonded
by means of an organic material such as resin,
rubber, shellac or other similar bonding agent.
Illustration No. 1
Example* of tke varum* type* of abrasive wheel*
included in thi* Code.
1.2.4 INORGANIC BONDED WHEELS
Inorganic wheels are wheels which are bonded
by means of inorganic material such as clay,
glass, porcelain, sodium silicate, magnesium
oxychloride. or metal. Wheels bunded with
clay, glass, porcelain or related ceramic ma-
terials are characterized as "vitrified bonded
wheels**.
283«
B-2
1.2.5 REINFORCED WHEELS
The term "Reinforced" as applied to grinding
wheels shall define a class of organic wheels
which contain strengthening fabric or fila-
ment.
The term "Reinforced** does not cover wheels
using such mechanical additions as steel rings,
steel cup backs or wire or tape winding. (See
appendix A page 87 for additional protection
devices.)
1.2.6 GRINDING SURFACE OR FACE
The grinding surface or face is the surface of
the grinding wheel upon which grinding is per-
formed.
1.2.5 REINFORCED WHEELS
REINFORCING FABRIC
Illustration No. 2.
Cross Section View
One method of reinforcing organic bonded wheel*.
1.2.6 GRINDING SURFACE OR FACE
GRINDING FACE J— H —
Type 1 — Straight wheel.
1.2.7 SAFETY GUARD
A safety guard is an enclosure designed to
restrain the pieces of the grinding wheel and
furnish all possible protection in the event that
the wheel is broken in operation. See section 4
page 27 for full description.
Type 11 — Flaring-cup wheel.
Illustration No. 3
Arrow indicates grinding face.
1.2.7 SAFETY GUARD
Illustration No. 4 J
The safety guard affords operator protection in case
of accidental breakage.
2839
B-3
1.2.8 WHEEL SPEED
Wheel speed shall be computed from the free
running speed of the machine spindle.
1.2.8 WHEEL SPEED
In Table 20 page 59, wheel speeds are classified
in surface feet per minute (sfpm). Machine
spindle speeds, however, are .usually indicated
in revolutions per minute. Therefore, one must
have a clear understanding of how these two
are related.
1.2.9 REVOLUTIONS PER MINUTE
Revolutions per minute (rpm) is the number
of complete turns that a grinding wheel makes
in one minute.
/
1.2.10 SURFACE FEET PER MINUTE
Surface feet per minute (sfpm) is the distance
in feet any one abrasive grain on the periph-
eral surface of a grinding wheel travels in one
minute.
Sarfaee Feet Per Minate — -
1.1 41( i diameter In Inches x r.p.m.
12
or
■2C 2 a diameter In Inch** z r.p.i
Eiamnleai (»> 24" diameter wheeMOOe rrrolntlene per mlnnte
Surface Fen per ■lnnte.2S2 a 24 x 1*00
C288 aXp.m.
<h> 12" diameter wheel, lOOt rerolutlont per minate
Sarface Feet per minate Jf2 a 12 a 1*00
2144 l.f.p.m.
i * i
■.EVOLUTION REVOLUTION .REVOLUTION REVOLUTION
V "x"
ROIHT "X"
Illustration No. 5
Point "X" has traveled a distance equal to the
circumference of the wheel. (S.H16 x diameter)
1.2.10 SURFACE FEET PER MINUTE
Surface feet per minute (sfpm) is the distance
in feet any one abrasive grain on the cutting
face travels in one minute. In Illustration No.
5 the point "x" on the cutting face travels, for
every complete turn, a distance equal to the
circumference, (3.1416 x diameter). Since the
diameter of a grinding wheel is usually indi-
cated in inches, it is necessary to divide the
result by 12 in order to obtain the number of
"surface feet per minute".
1.2.11 FLANGES
Flanges are collars, discs or plates between
which wheels are mounted and are referred
to as adaptor, sleeve, or back up type. See
section 5 page 42 for full description.
1.2.12 STEEL RINGS
Steel rings may be molded into certain organic
bonded grinding wheels in manufacture. Where
nsed, such rings act mainly to add rigidity to
the wheel as it approaches discard size and to
help retain the pieces of the wheel should ac-
cidental breakage occur at stub size. See Ap-
pendix A page 87.
2840
B-<t
1.2.13 THREADED BUSHINGS
Cup back, inserted type, round knurled and
prong anchor bushings as shown in Illustra-
tion 6 are generally motded on types 6 and 11
organic bonded cup wheels.
Bushings of round, hexagonal, square or simi-
lar designs may be cemented or molded into
the wheel holes, including cone and plug
wheels.
Adequate safety guards shall always be used I
with these wheels unless specifically excepted*
by the code. See section 4 page 27 and Appen-
dix A page 87.
1.2.14 REDUCING BUSHINGS
Reducing bushings are inserts or devices used
to reduce the hole size in a grinding wheel so
that it can be mounted correctly on a smaller
diameter spindle. Reducing bushings shall be
specifically designed, properly manufactured
and fitted for use in grinding wheels as speci-
fied in paragraph 3.11, page 24. Minimum hole
size as shown in Table 1 page 22 should not be
violated nor should the bushing ends interfere
with proper seating of the mounting flange or
flanges. (See section 6 page 52.) Reducing
bushings shall not be used to permit the opera-
tion of a grinding wheel in excess of its maxi-
mum operating speed.
1.2.15 TAPE OR WIRE WINDING
Tape or wire winding as used on the periph-
ery of cylinder, cup or segmented disc wheels
helps to retain the pieces of the wheel should
accidental breakage occur. See Appendix A
page 87.
1.2.13 THREADED BUSHINGS
Illustration No. 6
Hexagonal, prong anchor, round knurled
back bushings.
1.2.14 REDUCING BUSHINGS
and
cup
M
11
|0 -J
E*
.?.-.;
Illustration No. 7
One type of reducing buthing commonly need to
reduce a grinding wheel hole tize.
£2.16 CHUCK
A chuck is a fixture designed to hold abrasive
segments or certain types of grinding wheels
and is mounted on a machine spindle or ma-
chine face plate.
1.2.17 THE WHEEL MANUFACTURER
Any individual, partnership, corporation or
other form of enterprise which manufactures
any kind of abrasive wheel.
2841
1.2.18 THE MACHINE BUILDER
(a) Any Individual, partnership, corporation
or other form of enterprise which is en-
gaged in the development and or manu-
facture of any type of machine which uses
an abrasive wheel.
(b) One who converts, changes or otherwise
alters the original design of such ma-
chines.
1.3 Usage Definition
1.2.19 THE USER OF WHEELS AND
MACHINES
Any individual, partnership, corporation or
other form of enterprise which uses abrasive
wheels and machines.
1.3.1 CENTERLESS O.D. GRINDING
1.3 Usage Definition
1.3.1 CENTERLESS O.D. GRINDING
The precision grinding of the outer surface
of any cylindrical work piece which is rotated
by a regulating wheel and supported by a work
blade.
1.3.2 COPING
The sawing or grooving of any non-metallic
material with an abrasive wheel.
\
Illustration No. 8
Typical through feed center lest grinding operation.
i
ZSk2
ft- fa
1.3.3 CUTTING OFF
The slicing or parting of any material or part.
1.3.4 CYLINDRICAL O.D. GRINDING
The precision grinding of the outer surface of
any cylindrical work piece which is supported
at one or both ends.
1.3.5 INTERNAL GRINDING
The precision grinding of the inside surface
of the hole in a work piece.
1.3.6 OFF-HAND GRINDING
The grinding of any material or part which
is held in the operator's hand.
1.3.7 PORTABLE GRINDING
A grinding operation where the grinding ma-
chine is designed to be hand held and may be
easily moved from one location to another.
1.3.8 PRECISION GRINDING
Grinding operations performed by machines
used to finish work parts to specified dimen-
sions and finish requirements.
1.3.3 CUTTING OFF
;" "t
Illustration No. 9
Cutting ordinary bar stock, using a retinoid bonded
eutting-off wheel mounted on a dry, chopper
type eutting-off machine.
1.3.5 INTERNAL GRINDING
Illustration No. 10
Internal grinding of a large bore cylinder.
1.3.6 OFF-HAND GRINDING
Illustration No. ll
Offhand grinding on a double end pedestal grinder.
2843
6-r
^ 1.3.9 SAW GUMMING
The shaping and/or sharpening of saw teelh
by grinding.
1.3.10 SLOTTING
The grinding of a slot or groove in any ma-
terial or part.
1.3.11 SNAGGING
Grinding which removes relatively large
amounts of material without regard to close
tolerances or surface finish requirements.
1.3.12 SURFACE GRINDING
The precision grinding of a plane surface.
1.3.13 TOOL GRINDING
The precision grinding or sharpening of vari-
ous types of cutting tools.
1.3.9 SAW GUMMING
ILLUSTRATION NO. 12
Sharpening the teeth (Sato Gumming)
on a large band taw.
1.3.13 TOOL GRINDING
Wf/m\
ILLUSTRATION No. 13
Grinding a shell end mill.
1.3.14 TUCK POINTING
Removal, by grinding, of cement, mortar or
other non-metallic jointing material.
1.3.14 TUCK POINTING
\
1.4 Definitions and Limitations of
Wheel Shapes
i
The following wheel shape definitions and limi-
tations are safety code recommendations for
general use and should be used wherever possi-
ble. Wheel dimensions or shapes differing from
the standard recommendations below may be
used on specific machines with the approval of
the wheel manufacturer.
Illustration No. 14
Tuck pointing using a reinforced organic
bonded grinding wheel.
1.4 Definitions and Limitations of
Wheel Shapes
When using non-standard wheels, it is often
advisable for the user to consult the machine
builder concerning special problems in mount-
ing and guarding.
2844
6-8
1.4.1 TYPE 1 STRAIGHT WHEELS
Definition:
Type 1 straight wheels have diameter, thick-
ness and hole size dimensions and should be
used only on the periphery. Type 1 wheels
shall be mounted between flanges, see section
5 page 42.
Limitation:
Hole dimension (H) should not be greater than
two-thirds of wheel diameter dimension (D)
for precision, cylindrical, centerless or surface
grinding applications. Maximum hole size for
all other applications should not exceed one-
half wheel diameter. Inorganic wheels used
in snagging operations should have a maxi-
mum hole size of not more than one quarter of
the wheel diameter.
1.4.2 TYPE 2 CYLINDER WHEELS
Definition:
Type 2 cylinder wheels have diameter, wheel
thickness and rim thickness dimensions. Grind-
ing is performed on the rim face only, dimen-
sion W. Cylinder wheels may be plain, plate
mounted, inserted nut or of the projecting
stud type.
Limitation:
Rim height, T dimension, is generally equal to
or greater than rim thickness, W dimension.
1.4.3 ABRASIVE DISC WHEELS
Definition:
Abrasive discs have diameter, thickness and
hole size dimensions. They are used in a man-
ner similar to type 2 cylinder wheels. (See sec-
tion 3:13 page 25 and 3.14 page 26.)
Limitation:
Wheel thickness, T dimension, must be less
than rim thickness, W dimension.
1.4.4 TYPE 4 TAPER SIDED WHEELS
(Non Standard Shape)
Definition:
Type 4 taper sided wheels have diameter,
wheel thickness, grinding face thickness and
hole size dimensions. Type 4 wheels have the
same limitations on hole size and usage as
type 1 wheels, definition 1.4.1 page 8.
Limitation:
Grinding face, thickness dimension 17, must
be equal to or greater than one half T dimen-
sion. J. dimension shall be large enough to ac-
commodate suitable flanges. If tapered safety
flanges are used, J dimension and degree of
taper required shall be determined by the wheel
manufacturer.
1.4.1 TYPE 1 STRAIGHT WHEELS
GRINDING FACE
Illustration No. 15
Type 1 — Straight Wheel
Peripheral grinding wheel having a diameter,
thickness and hole.
1.4.2 TYPE.2 CYLINDER WHEELS
W
ar
.GRINDING
FACE
Illustration No. 16
Type t — Cylinder Wheel
Side grinding wheel having a diameter, thickness
and wall — wheel is mounted on the diameter.
1.4.3 ABRASLVE DISC WHEELS
Illustration No. 17
Typical example of the various types of
abrasive disc wheel*.
1.4.4 TYPE 4 TAPER SIDED WHEELS
7' (Non Standard Shape)
r
t-
GRINDING FACE
Illustration No. 18
Type 4 — Taper Sided Wheel
Peripheral grinding wheel having a diameter, wheel
thickness, grinding face thickness and hole
site dimension*.
2845
8-9
1.4.5 TYPE 5 RECESSED ONE SIDE
WHEELS
Definition:
Type 5 recessed one side wheels have diameter,
thickness and hole size dimensions and in ad-
dition also have a recess diameter and depth
dimension. Type 5 wheels are subject to the
same limitations of use and mounting as type
1 wheels definition 1.4.1 page 8 and section 6
page 52.
Limitation:
Type 5 wheels are subject to the same limita-
tion of hole size as type 1 wheels definition
1.4.1 page 8. In addition recess depth, F di-
mension, should not exceed 50% of wheel
thickness, T dimension, and diameter of recess,
P dimension, shall be large enough to accom-
modate a suitable flange as recommended in
section 5 page 42.
1.4.6 TYPE 6 STRAIGHT CUP WHEELS
Definition:
Type 6 cup wheels have diameter, thickness,
hole size, rim thickness and back thickness di-
mensions. Grinding is always performed on
rim face, W dimension.
Limitation:
Minimum back thickness, E dimension, should
not be less than l / 4 T dimension. In addition,
when unthreaded hole wheels are specified, the
inside flat, K dimension, must be large enough
to accommodate a suitable flange, see flange
recommendations, section 5 page 42.
1.4.7 TYPE 7 DOUBLE RECESSED
WHEELS
Definition:
Type 7 double recessed wheels have diameter,
thickness and hole size dimensions and in ad-
dition also have recess diameters and depth
dimensions. Type 7 wheels are subject to the
same limitations of use and mounting as type
5 wheels, definition 1.4.5 page 9 and section 6
page 52. ,'
Limitation:
Type 7 wheels are subject to the same limita-
tion of hole size as type 1 wheels, section 1.4.1
page 8. In addition th^ combined depths of
recess, F and G dimensions, should not exceed
50% of wheel thickness, T dimension.
/
1.4.5 TYPE 5 RECESSED ONE SIDE
WHEELS
GRINDING FACE
Illustration No. 19
• Type S — Wheel, recessed one ride
Peripheral grinding wheel having one aide ttraight
or flat and the opposite tide recessed. Recessed wheels
allow a wider faced grinding wheel to be used when
the available mounting thickness (E) it lest than
the required overall thieknest (T). The recess allows
grinding clearance for the nut and flange.
1.4.6 TYPE 6 STRAIGHT CUP WHEELS
GRINDING FACE
Illustration No. 20
Type 6 — Straight-cup Wheel
Side grinding wheel having a diameter, thickness and
hole with one tide ttraight or flat and the opposite
tide recetted. Thit type, however, differs from Type 5
in that the grinding it performed on the wall of the
abrasive created by the difference between the di-
ameter of the recess and the outside diameter of the
wheel. Therefore, the wall dimension "W" takes
precedence over the diameter of the recess as an
essential intermediate dimension to describe
thit shape type.
1.4.7 TYPE 7 DOUBLE RECESSED
WHEELS
V»
855^35
7
GRINDING FACE
Illustration No. Si
' Type 7 — Whttl. recessed two tides
Peripheral grinding wheels having 1 both tides rteetted
to allow grinding clearance for both flanges or re-
cetted to that unusually wide faced wheels may be
mounted when the available mounting thickness (E)
,it lets than the overall thieknest (T).
28*6
R-10
1.4.8 TYPE 11 FLARING CUP WHEELS
Definition:
Type 11 flaring cup wheels have doable diame-
ter dimensions D and J, and, in addition have
thickness, hole size, rim and back thickness
dimensions. Grinding: is always performed on
rim face, W dimension. Type 11 wheels are
subject to all limitations of use and mounting
listed for type 6 straight sided cup wheels
definition 1.4JJ page 9 and section 6 page 52.
Limitation:
Minimum back thickness, E dimension, should
not be less than Va T dimension. In addition
when unthreaded hole wheels are specified the
inside flat, K dimension, shall be large enough
to accommodate a suitable flange, see flange
recommendations section 5 page 42.
1.4.8 TYPE 11 FLARING CUP WHEELS
. ' . . ' At * .Ml '
I— H —
J-
.GRINDING
FACE
Illustration No. 22
Type 11 — Flaring-cup Wheel
Side, grinding wheel having a wall flared or tapered
outward from the back. Wall thickness at
the back is normally greater than, at
the grinding face (W).
1.4.9 TYPE 12 DISH WHEELS
Definition :
Type 12 dish wheels have diameter, thickness,
rim thickness and back thickness dimensions.
In addition type 12 wheels always have a face
thickness, U dimension. Grinding may be per-
formed on both A and U dimensions.
Limitation:
Minimum back thickness, E dimension, should
be equal to or greater than Yi wheel thickness,
T dimension. If unthreaded hole wheels are
specified K dimension shall be large enough
to .accommodate a suitable flange, see flange
recommendations section 5 page 42.
1.4.9 TYPE 12 DISH WHEELS
-O
-K
<£kJ:j?.v->v,
Illustration No. 23
Type IS — Dish Wheel
Side grinding wheel known as a dish, differing from
a Type 11 in that Type IS always has a "U" dimen-
sion. The "W" dimension of a Type 11 becomes the
"A" dimension of a type 12. The grinding may be
performed on the "U" face.
1.4.10 TYPE 13 SAUCER WHEELS
Definition:
Type 13 saucer wheels have diameter, thick-
ness, hole size and back thickness dimensions.
Grinding shall be performed on wheel periph-
ery, U dimension, only.
Limitation:
Where unthreaded hole wheels are specified,
J and K dimensions shall be large enough to
accommodate suitable flanges, see section 5
page 42. In addition, wheel thickness shajfl
be uniform throughout, U dimension should
always equal E dimension.
1.4.10 TYPE 13 SAUCER WHEELS
Illustration No. 24
Type 13 — Saucer Wheel
Peripheral grinding wheel known as a saucer, differing
from a Type IS in that the eross-seetion
it equal throughout (U,=EJ. ,
The face is always half-round with R= J '.
10
2847
B-ll
1.4.11 TYPES 16, 17, 18, 18R and 19 CONE
AND PLUG WHEELS
1.4.11 TYPES 16, 17, 18, 18R and 19 CONE
AND PLUG WHEELS
Definition:
Type 16 cones have a curved aide with a nose
radios. Type 17 cones have straight sides with
or without a nose radios. Types 18 and 18R
plug wheels are cylindrical in shape with either
a square or carved grinding end. Type 19 cone
wheels are a combination of cone and plug
type shapes and are nsoally specified where
base dimension D in a type 17 cone wonld not
provide an adequate cross section of abrasive.
All types of cone and plug wheels are manu-
factured with blind hole threaded bushings
and may be used on all surfaces except the flat
mounting surface D.
Limitation:
Cone and plug type wheels are mounted by
being screwed onto a threaded machine spin-
dle so that surface D seats firmly against an
unrelieved, flat back-up flange. (See section
3.12 page 24.) It is recommended that the
maximum size or mass of the above cones and
plugs be not greater than that of a 3" diam-
eter by 5" long type 18 plug wheeL
Type 18 — Cone, curved tide
Curved tided cone Kith a radiut note tometimet
referred to at "Bullet thape".
OtWCMNO CACX
i
Type 17 — Cone, ttraight tide, tquare tip
Cone with a . ttraight tide, tquare Up. When the
erott-eeetion of the abrative at the bottom, of the
blind hole threaded bushing it inadequate, ute Type-It.
Type 18 — Plug,
tquare - end.
Plug — cylindrical in
thape with a
tquare end.
Type 18R — Plug,
round end.
Plug — cylindrical in
thape with a radiut note.
\
Type 1» — Plugt, conical end, tquart tip.
Combination cone and plug with a tquare tip timilar
to Type 17 and the cylindrical portion etmilar to
Type 18. The cylindrical portion "S" it normally
equal to or greater than the depth of the blind hole
threaded buthing "B".
Iu.usTU.noN No. 26
Varum* typet of cone and plug wheel*.
11
/
2848
B-12
.12 TYPES 20, 21, 22, 23, 24, 25, 26
RELIEVED AND/OR RECESSED
WHEELS
: -tion:
» 20 through 26 relieved and/or recessed
Is have diameter, thickness, hole size, re-
diameter and depth dimensions and in
ion may be concaved on one or both sides.
i 20 through 26 wheels are subject to the
limitations of use and mounting as type
eels, definition 1.4.5 page 9 and section 6
52.
ition:
.ved relief depths shall be considered as
tes and added to straight recess depth or
s for determination of total wheel recess
. Total recess depths should not exceed
of wheel thickness, T dimension.
1.4.12 TYPES 20. 21, 22,-23, 24, 25, 26
RELIEVED AND/OR RECESSED
WHEELS
SHS
Type tO — Wheel, relieved one tide.
Peripheral grinding wheel having erne tide straight
or fiat and the other tide relieved to a fiat.
mm
Type SI — Wheel, relieved two tide*.
Peripheral grinding wheel having both tides
relieved to a fiat.
Type tt — Wheel, relieved one tide, reeetted
other tide.
Peripheral grinding wheel having one tide reeetted
and the other tide relieved to a flat.
l— H— I
Type tS — Wheel, relieved and reeetted tame tide.
Peripheral grinding wheel having one tide ttraight
or flat and the other tide relieved to a reeett.
LEBI
Type tk — Wheel, relieved and reeetted one tide,
reeetted other tide.
Peripheral grinding wheel having one tide reeetted
and the other tide relieved to a reeett.
Type tS — Wheel, relieved and reeetted one tide,
relieved other tide.
Peripheral grinding wheel having one tide relieved
to a flat and the other tide reheved to a reeett.
E&
j
Type t$ — Wheel, relieved and reeetted both tide:
Peripheral grinding wheel having both tide*
j relieved to a new.
IlXOST*Jk.T10Jf No. Z6
Variant typet of relieved mud/or reeetted wheelt.
12
B-13
1.4.13 TYPES 27 AND 28 DEPRESSED
CENTER WHEELS
Definition:
Types 27 and 28, depressed center wheels, have
diameter, thickness and hole size dimensions.
Both types are reinforced, organic bonded
wheels having off-set hubs which permit side
and peripheral grinding operations without in-
terference with the mounting. Type 27 wheels
are manufactured with flat grinding rims per-
milting notching and cutting operations. Type
28 wheels have saucer shaped grinding rims.
Limitation:
Special supporting, back adaptor and inside
flange nuts are required for the proper mount-
ing of these types of Wheels, see section 6.15
page 56.
Mounts which axe affixed to the wheel by the
manufacturer may not require an inside nut
and shall not be reused.
1.4.13 TYPES 27 AND 28 DEPRESSED
CENTER WHEELS
Type tS
Illustration No. 27
Types Z7 and 18 — Wheel*, depreiaed center.
Peripheral grinding wheel having an offset center
and used on right angle head portable grinders.
Grinding may also be done on
the ride of the wheel.
1.4.14 TYPE 27A DEPRESSED
CENTER WHEELS
Type 27A depressed center, cutling-off wheels
have diameter, thickness and hole size dimen-
sions. They are reinforced, organic bonded,
off-set hub type wheels, usually 16" diameter
and larger, specially designed for use on cut-
ting-off machines where mounting nut or outer
flange interference cannot be tolerated.
Limitationt
See section 5.1 page 42 and illustration 28 for
mounting details.
FLATFLANGES
MOUNTING BOLTS
lLLWmUTION Mo. 28
Type tTA whert shoving typical mounting details.
13
2850
B-14
1.4.15 CUTTING OFF WHEELS
1.4.15 CUTTING OFF WHEELS
Definition:
Cutting off wheels have diameter, thickness
and hole size dimensions and are subject to all
limitations of mounting and use listed for type
1 wheels, definition 1.4.1 page 8 and section 6
page 52. They may be steel centered, diamond
abrasive or organic bonded abrasive of the
plain or reinforced type.
Limitation:
Cutting off wheels are recommended only for
use on specially designed and fully guarded
machines and are subject to the following
maximum thickness and hole size limitations.
Wheel Diameter
Max. Thickness
6" and smaller
««"
Larger than 6" to 12"
V<"
Larger than 12" to 23"
V»"
Larger than 23"
Vi"
Maximum hole size for cutling-off wheels
should not be larger than l / 4 wheel diameter.
1.4.16 COPING WHEELS
Definition:
Coping wheels are peripheral cutting wheels,
and have diameter, thickness and hole size di-
mensions. They may be metal or organic bond-
ed, solid or steel centered, and are subject to
the same limitations of use and mounting as
type 1 wheels, definition 1.4.1 page 8 and sec-
tion 6 page 52.
Limitation:
Coping wheels are recommended for use only
on specially designed and fully guarded ma-
chines.
1.4.17 TUCK POINTING WHEELS
Definition:
Tuck pointing wheels, usually type 1, rein-
forced organic bonded wheels have diameter,
thickness and hole size dimension. They are
subject to the same limitations of use and
mounting as type 1 wheels definition 1.4.1 page
8 and section 6 page 52.
Limitation:
Wheels used for tuck pointing should be rein-
forced, organic bonded, (See paragraph 4.5.1,
Exception B, page 32.)
Illustration No. 29
A wet machine with horizontal movement
for elabbing.
1.4.16 COPING WHEELS
Illustration No. 80
Slotting. a block of marble to contour using a
coping wheel.
1.4.17 TUCK POINTING WHEELS
Illustration No. SI
Tuck pdntrng granite utxng a etraigki retinoid
rttn/c.ed wheel
14
2851
1.4.18 MOUNTED WHEELS
1.4.18 MOUNTED WHEELS
Definition:
Mounted wheels, usually 2" diameter or small-
er, and of various shapes, may be either or-
fanie or inorganic bonded abrasive wheels.
They are secured to plain or threaded steel
mandrels.
Limitation:
See section 10 page 69 for safe operation and
speeds for mounted wheels.
Typical
Illustration No. 82
plet of grinding wheel* known at
mounted w"heeU.
1.4.19 THREADED HOLE CUP
WHEELS
Threaded hole cup wheels types 6 and 11 are
designed for use on vertical, right angle head,
or flexible shaft portable grinders. They have
one central threaded bushing, securely an-
chored in place. They are mounted by being
screwed onto a threaded machine spindle so
that the wheel back seats firmly against an
unrelieved flat back flange.
Limitation:
Threaded hole cup wheel mounting should not
be used with wheels larger than 6" diameter.
Back flanges used in mounting threaded hole
cup wheels shall be flat and unrelieved.
1.4.20 MODIFIED TYPES 6 & 11
WHEELS (TERRAZZO)
Some type 6 ft 11 cup wheels used in the ter-
razzo trade have tapered K dimensions to
match a special tapered flange furnished by
the machine builder.
Limitation:
These wheels shall be mounted only with a
•pedal tapered flange.
1.4.19 THREADED HOLE CUP
WHEELS
Illustration No. 83
A cup wheel with an inserted buehing. Note the
bushing and abrasive are in uniform
contact with the back flange.
Illustration No. 83A
A cup wheel with a prong anchor bushing. Note the
bucking and abrasive are in uniform
contact with the back flange.
TAPERED "K" DIMENSION
TAPERED "K" DIMENSION
15
TYPE 6 WHEEL CTEW»AZZOJ TVPE ■ WHEEL CTERRA2ZO)
Illustration No. 34
28S2
C-?
CODE REGULATIONS
Section 2
HANDLING, STORAGE AND
INSPECTION
2.1 Handling
All grinding wheels are breakable and there-
fore care shall be exercised in handling and
storage to prevent damage. The following
rules, which are based on experience, shall al-
ways be observed.
(a) Handle wheels' carefully to prevent drop-
ping or bumping.
(b) Do not roll wheels (hoop fashion).
(c) Use trucks or other suitable conveyances,
which provide support and protection in trans-
porting all wheels which cannot be carried by
hand.
(d) Place wheels carefully on a shelf or rack
or in bins, boxes or drawers.
Explanatory Information
(NOT » ART OF AMU CODE)
Section 2
Handling, Storage and Inspection
2.1 Handling
AH grinding wheels must be handled carefully.
It should be realized that grinding wheels are
necessarily manufactured in varying strengths
to grind properly.
Some grinding wheels are stronger than oth-
ers, but all grinding wheels can be broken by
mishandling.
22 Storage
2.2 Storage
Suitable racks, bins, drawers or boxes shall be
provided to store the various types of wheels
used. (See Figs. 1, 2 and 3 pages 17-18.)
Wheels shall not be stored subject to:
(a) Exposure to high humidity, water or
other liquids.
(b) Freezing temperature.
(c) Any temperature low enough to cause con-
densation on the wheels when moving them
from storage to an area of higher temperature.
Grinding wheels must be protected while
awaiting use. Wheel storage should be ar-
ranged to allow for removal of wheels without
disturbing or damaging other wheels. Storage
and records should also be set up to allow for
wheel use on a rotational basis so that wheels
will be in storage a minimum length of time.
This minimizes the possibility of damage from
lengthy storage. Such suitable storage should
be available for partly used wheels as well as
new wheels.
16
28 53
C-3
Grinding wheel storage racks should be de-
signed, constructed and located to fit the needs
of the user. The following factors should be
considered:
Location
All grinding wheels should be stored in~a dry
area in rooms not subject to extreme tempera-
ture changes since some bonds may be af-
fected by excessive humidity, dampness and
extreme temperature differentials. Racks
should be located as near as practical to the
grinding location, but never where there is
danger of damage from passing trucks, crane
handling or excessive vibration.
FIGURE NO. 1
A well-designed grinding wheel storage area used
by a large industrial plant.
•*"«■/<*- ftttdt Vltrifi«t
Grin/in f &h*tl
M--MH-H.1:-
t-H-h-HAvfr
t^B
M±£li
tncli'nr* J**/t.
XSimf/v Mitmtt
*A-Ji^.ca.ii *■_■•] *>.-.l',v -A- .!•'■■'
at
5W
jp
i
**S/*m Stze
i
j±
front mf J*pp0-fj
Tmm
l*rf Jhmiftrt T T r»l we*/* t-^rr "f
151--^
FIGURE NO. 2
This drawing illustrates a rack design which is suitable for handling a wide rariety or grinding wheels.
17
2854
C-*
FIGURE NO. 3
The radons sizes and shapes of wheels are located in
the racka ao that they are easily accessible and
protected from damage.
2.3 Inspection
Immediately after unpacking, all wheels shall
be closely inspected to make sure that they
have not been damaged from handling, ship-
ping or other causes. As an added precaution,
wheels should be tapped gently with a light
non-metallic implement, such as the handle
of a screw driver for light wheels, or a wooden
mallet for heavier wheels. If they sound
cracked (dead), they shall not be used. This is
known as the "Ring Test**. (See Figs. 4 and 5
page 19.)
Storage Methods
The racks, bins or drawers should be con-'
stmcted bo that each of the various types of
wheels can.be stored in an orderly and safe
manner. (See Fig. 2 page 17.) Wheel selection
should be possible with a minimum of han-
dling.
The selection of racks, bins, boxes or drawers
for storage depends on the size and type of
wheels. The following suggestions should be .
considered.
Thin organic bonded wheels such as those used
for cutting-off should be laid flat on a flat sur-
face of steel or similar rigid material away
from excessive heat or moisture to prevent
warpage. Not even blotters should be allowed
between stacked thin wheels. If thin wheels
are supplied with blotters attached, suitable
* separators should be used to preserve flatness.
Straight or tapered wheels (Types 1, 4, 5, 7,
13, 20, 21, 22^23, 24, 25 and 26) of appreciable
thickness are best supported in racks (see Fig.
2 page 17). Preferably the racks should pro-
vide a cushioned two-point cradle support to
prevent the wheels from rolling. Partitions
are helpful in facilitating wheel selection with
a minimum of handling.
Cylinder wheels' (Type 2), large straight cup
wheels (Type 6), large dish wheels (Type 12)
and large saucer wheels (Type 13) may be
stacked on flat sides with some form of cush-
ioning material between them; or they may be
stored on edge like large straight wheels.
Flaring cup wheels (Type 11) are best stored
as Illustrated in Fig. 2 page 17 to prevent chip-
ping of edges.
Small wheels (Approximately 4 inches or less
in diameter), except flaring cup wheels
(Type 11), are often stored in boxes, bins, or
drawers.
2.3 Inspection
The first inspection should be made on the
original shipping container. If there is visi-
ble evidence of damage to the container, spe-
cial care must be used in the inspection of
the wheels.
18
28 55
C-b
\
Wheels most be dry and free from sawdust
when applying the ring test, otherwise the
sound will be deadened. It should also be noted
that organic bonded wheels do not emit the
same clear metallic ring as do vitrified and sili-
cate wheels.
FIGURE NO. 4
"Ring Test"
If the wheel is not too heavy, it may be sus-
pended from the hole on a small pin or the
finger. (See 111. No. 85.) Heavier wheels may
be allowed to rest in a vertical position on a
clean, hard floor.
'Tap" the wheel gently with
a non-metallic implement
such as a wooden screw
driver handle for light
wheels and a wooden mallet
for heavy wheels. The best
spot to "tap" a wheel for
the ring test is about 45 de-
grees either side of the ver-
tical center line and about
1 or 2 inches from the pe-
riphery. (See Figs. 4 and
' Illustration No. 36
o
"Tap" wheels about 45 degrees each side of
the vertical center line and about 1 or 2 inches
from the periphery as indicated by the spots in
Fig. 4 and Fig. 5.
Then rotate the wheel 45 degrees and repeat
the test.
A sound and nndamaged wheel will give a clear
metallic tone. If cracked, there will be a dead
sound and not a clear "ring."
If struck directly along the vertical center line,
the "ring", even in a sound wheel, is some-
times muffled and may give the erroneous im-
pression- that the wheel is cracked. This is
especially true with large wheels which are
supported on the floor when conducting this
test. (See Fig. 5.) It is sometimes noticeable
also- when the wheel is suspended from the
hole. It is recommended that the test be re-
peated after rotating the wheel 45 degrees to
the right or left.
Repeat this "ring test" immediately before
mounting. either a new or used wheel on a
machine,=especially if the wheel has been in
storage hit out of service for a considerable
time. In making this test it must be realized
that wheels bonded with organic material do
not give forth the same clear metallic sound
as do vitrified and silicate wheels. Also wheels
must be dry and free from sawdust when ap-
plying the test, otherwise the sound will be
deadened.
Comparison of the sound with other wheels of
the same lot and specification will allow rejec-
tion of any wheel with a suspiciously different
ring before use.
19
C-6
2856
CODE REGULATIONS
Section 3
GENERAL MACHINE
CONDITIONS
Explanatory Information
<MOT PAST OF ANSI CODE)
Section 3
General Machine
Conditions
3.1 Machine Design and Maintenance
It shall be the machine manufacturer's re-
sponsibility to design, and the user's responsi-
bility to maintain, his machines for safe oper-
ating condition.
The following areas are important to fulfill
these obligations.
3.2 Safety Guards
Grinding machines shall be equipped with safe-
ty guards in conformance with the require-
ments covered in section 4 page 27.
3.3 Power
Grinding machines should be supplied with
sufficient power to maintain the rated spindle
speed under all conditions of normal operation.
3.4 Exhaust Provision
Stationary machines used for dry grinding
should have provision made for connection to
an exhaust system. ^
For detailed recommendations. Reference is
made to "American National Standard For
Ventilation Control of Grinding, Polishing and
Buffing Operations (Z43.1)." Copies may be ob-
tained from The American National Standards
Institute. /
3.1 Machine Design and Maintenance
Grinding is a safe operation under normal con-
ditions. Severe stresses can be set up in the
wheel if established safe operating practices
are not maintained. Only machines designed
for the required spindle speed with suitable
bearings to take the pressure and thrust of the
grinding. operation are recommended.
Proper maintenance of grinding machines is
very important to insure safe operation.
Grinding machine maintenance should be per-
formed only by qualified personnel.
3.2 Safety Guards
Safety guards must be used on grinding ma-
chines to insure protection in case of an acci-
dental wheel breakage. (See section 4.1 page
27 for exceptions.)
3.3 Power
If the grinding wheel speed is reduced materi-
ally under normal grinding pressure, its cut-
ting ability is decreased and excessive heat
and pressure often result. Adequate power
will avoid this hazard.
3.4 Exhaust Provision
iLLUSTfcATION NO. 36
Note th* excellent provision* employed to oxkauit
grinding dust.
20
2857
C-7
3.5 Diameter of Spindle
3.5 Diameter of Spindle
Table 1 page 22 shows the minimum diameters
of spindles which should be used for wheels of
various sizes. It applies to machines where
wheels are not mounted between bearings. The
use of heavier spindles than those listed in
this table is often desirable.
Standard machine design generally conforms
to the minimum spindle diameter requirements
in Table 1 page 22. Investigation has shown
that requests for wheels with undersize holes
often result from the desire to use larger diam-
eter wheels than were originally intended for
the machine.
3.6 Flanges
3.6 Flanges
Grinding machines shall be equipped with
flanges in accordance with the requirements
listed in section 5 page 42.
3.7 Work Rests
On offhand grinding machines (see section
1.3.6 page 6), work rests shall be used to sup-
port the work. They shall be of rigid construc-
tion and designed to be adjustable to compen-
sate for wheel wear.
Work rests shall be kept adjusted closely to
the wheel with a maximum opening of </g" to
prevent the work from being jammed between
the wheel and the rest, which may cause wheel
breakage. The work rest shall be securely
clamped after each adjustment. The adjust-
ment shall not be made with the wheel in
motion.
3.8 Limiting Wheel Diameter
Grinding machines should be provided with a
means of limiting the diameter of wheel which
can be mounted. The safety guard is generally
satisfactory for this purpose on single speed
machines.
On variable speed machines, the speed shifting
device should be connected with an adjustable
guard or another diameter Bmlting device to
prevent the mounting of a wheel which might
run at higher than the recommended surface
■peed.
Proper selection, use and maintenance of
flanges are all essential factors in the safe use
of grinding wheels. See section 5 page 42.
3.7 Work Rests
Illustiution No. 87
This floor stand grinder has a work reit which is
property adjusted. Note the provisions for
work-rest adjustment.
3.8 Limiting Wheel Diameter
On variable speed machines, a positive me-
chanical or manual regulation check should
be maintained to avoid overspeeding another
or full size wheel after the original wheel stub
has been removed.
21
2858
C-8
TABLE 1
K>
OB
MINIMUM DIAMETERS OF MACHINE SPINDLES AT POINT OF MOUNTING FOR WHEELS OF VARIOUS
DIAMETERS AND THICKNESSES OPERATING AT STANDARD SPEEDS AS LISTED IN TABLE 20
n
i
8
-----
Thickness of Wheel, 1
hehei
Diam-
eter of
Leu
Than
*
Is
M
H
K
1 1 IK 1 ltt I 2 J 2U
2H 1 2%
1.
|.«
|..
1 >
1 .1 ..
Wheel
%
2
Va
%
A
A
*4
V*
%
%
%
%
%
*4
Vt
Vi
%
Vt
Vt
%
%
3
%
%
u
%
%
%
%
%
%
Vi
%
V4
Vt
Vt
V4
%
%
%
%
4
ft
yV
y 8
%
%
%
%
%
%
Vi
Vi
%
%
%
%
%
%
%
%
6
%
%
%
%
V4
V2
V*
Vt
Vi
Vt
%
%
%
%
%
%
"A
%
»/+
6
%
Vt
Vt
V4
V4
Vt
V4
Vi
%
%
%
%
%
%
%
%
%
%
1
7
%■
Vt
Vi
Vt
Vi
Vt
V4
%
%
%
%
%
%
%
%
%
1
1
1
8
%
Vt
%
Vt
Vt
%
%
%
%
%
%
%
%
1
1
1
1
1
1
9
%
%
%
%
%
%
%
%
%
%
1
1
1
1
1
1
H/4
VA
1%
10
%
%
%
%
%
%
%
%
%
%
1
1
1
1%
1%
1*4
1%
VA
VA
12
%
%
%
%
%
%
%
%
l
1
1
1
1
1*4
1%
1'/+
VA
1*4
VA
14
%
%
8 4
%
%
I
1
1
1
1
1
VA
VA
VA
VA
VA
VA
1*4
VA
16
%
1
1
1%
114
1%
1%
114
VA
VA
VA
VA
VA
VA
VA
VA
VA
1%
18 __
%
1
1
1V4
U4
m
1*4
VA
VA
va
VA
VA
VA
VA
VA
1%
1%
1%
20
1
1
1
m
i'/i
U4
VA
VA
VA
VA
VA
VA
VA
VA
VA
1%
VA
W
2
24
1
1
1
1%
VA
VA
VA
va
VA
VA
VA
1%
in
1%
2
2
2
26
1
1
1
1%
1V4
W>
VA
VA
VA
1%
1%
1%
1%
2
2
2
2
2
30
1
VA
1V4
144
1%
114
VA
VA
\%
1%
1%
1%
2
2
2
2
2H
214
2%
36
V/i
l%
1%
1%
1%
1%
2
2
2
2
2
2
2%
21,4
2%
214
2*4
2%
2%
40
1%
2
2
2
2
2
2*4
2%
2%
214
2V4
2*4
2*4
2«4
2%
2%
2%
2%
2%
44
2
2'/*
2V»
214
2Vt
2%
2%
2%
2%
3
3
3
3
3
3V4
3%
3*4
3V4
314
48
214
.2%
2%
2%
2%
2%
2%
3
3
3
314
3*4
314
3%
314
31/2
814
3V4
4
53
214
3
3
3
3
3l/ 2
3«/2
3»/i
3*4
314
3«/2
314
3*4
3*4
4
4
4
4
4V4
60
2%
31/5
3«/2
3!4
8%
3'/*
3%
4
4
4
4
4
4
4
4
4V4
4%
5
6
72
3
314
314
314
3"/*
3Vi
8%
4
4
4
4*4
414
4V4
4!4
4*4
5
5
6
6
NOTE: For tpeedt exceeding thote listed in Table to page 59, for unusually tevtrt operations and for wheel* with heavy mounting* (tuch at bolted-on abra-
1 'tiee*), the tpindle sixes shown in the above table mag not be adequat' asmuch as the proper tpindle $ixe it dependent upon many factors, /- "'
t iitral design of the machine, type of bearing*, quality of material*, w inship and application of wheel, a simple table it not practicable. W.
larger than specified by the machine manufacturer should not be used.
3.9 Direction of Machine Spindle
Thread
3.9 Direction of Machine Spindle
Thread
If wheels or flanges are secured by means of a
central spindle nut, the direction of the thread
shall be in such relation to the direction of
rotation that the nut will tend to tighten as
the spindle revolves. The following rule will
assist in determining the proper relationship:
"To remove the nut it must be turned in the
direction that the spindle revolves when the
wheel is in operation."
3.10 Length of Machine Spindle
Thread
If wheels are mounted by means of a central
spindle nut and flanges, two conditions shall
be maintained:
1. Spindles shall be of sufficient length to
allow a full nut mounting.
2. Threaded portion shall be of sufficient ex-
tent so that the threading shall extend well
inside the flange but not more than half way
within the hole of the wheel.
On double-end floor stands and bench grinders
one end of the spindle must therefore have a
right hand thread and the other a left hand
thread. Whenrre-assembling such machines
after repairs, care shall be used to properly
replace the Bpindle, with respect to direction
of threads.
Illustration No. 88
The direction of rotation of the eutting-off lohieel u
indicated by the arrow on the guard. Thit t* alto the
direction the nut mutt be turned for removal.
3.10 Length of Machine Spindle
Thread
FIXED FLANGE
BLOTTERS
IlXUffnUTION No. 89
The tpindle i$ of sufficient length to accommodate
tk* wheel and flanget.
23
O10
2860
3.11 Size of Spindle or Mount
3.11 Size of Spindle or Mount
Grinding wheels shall fit freely on the spindle
(wheel sleeves or adaptors) and remain free
under all grinding conditions.
To accomplish this, the spindle or wheel mount
shall be made to nominal (standard) size plus
.000 minus .002 inches. The wheel hole shall
be made suitably oversize to a 8 s u r e safety
clearance under the conditions of operating
heat and pressure.
To avoid rupturing pressure in the wheel hole,
the diameter of the spindle or wheel mount
shall be kept within the limits of plus zero,
minus .002 inches. The hole in the wheel must
be suitably oversize so that the wheel fits
freely but not loosely under all operating con-
ditions, to allow for expansion of the wheel
spindle or mount caused by the heat of opera-
tion.
3.12 Threaded Hole Wheels
3.12 .Threaded Hole Wheels
Machines on which threaded hole wheels are
mounted shall be provided with spindles which
are so threaded as to allow the wheel to be
screwed firmly and flat against the back flange.
(See Figs. 6 and 7.)
The back flange shall be flat, unrelieved, se-
curely fastened and square to the spindle axis.
(See III. 40.) The fixed back flange shall be of
sufficient diameter to insure proper support to
the wheeL (See Table 13 page 48.)
The direction of the thread shall be such that
to remove the wheel it must be turned in the
same direction that it rotates when in use.
If threaded hole wheels are of cone or plug
shape with blind holes, the length of the spin-
dle and the depth of the hole shall be such
that the end of the spindle shall not touch
the bottom of the wheel hole.
A relieved back flange shall not be used. If
made with a relief, the flange will cause the
bushing. to be pulled out of the wheel, as
shown in Illustration 40.
The fixed back flange should be perfectly flat
and heavy enough to prevent distortion.
Illustration No. 40
Unrelieved and relieved flange.
If the spindle stops quickly when power is shut
off, the-renergy stored in the spinning wheel
may cause the wheel to unscrew from the
spindle and "Spin Off" the machine.
To help prevent "spinning off" the threads on
the machine spindle should be maintained in
good condition and the wheel should be held
in contact with the work piece until the wheel
has stopped.
FIGURE NO.
FIGURE NO. 7
24
2A61
C-li
3.13 Mounting of Abrasive Discs
(Inserted Nut, Inserted Washer
and Projecting Stud Type)
Machines on which inserted nnt wheels are
mounted shall be provided with a steel disc
wheel (machine face plate) of approximately
the same diameter as the wheel, and of suffi-
cient thickness to provide necessary support.
Minimum steel disc wheel (machine face plate)
thicknesses for disc grinders are shown in
Table 2.
TABLE 2
MINIMUM THICKNESS OF STEEL DISC
WHEELS (MACHINE FACE PLATE)
FOR MOUNTING ABRASIVE DISCS
Diameter
Inches
Minimum
Thickness
Inches
8 to 14 inclusive
15 to 18 inclusive
19 to 26 inclusive
27 to 36 inclusive . . .
87 to 40 inclusive
41 to 72 inclusive
%
H
%
%
1
IVi
Screw holes in steel disc wheel (machine face
plate) should be accurately located to match
the threaded holes in the inserted nuts in the
wheel, and shall be large enough so that the
screws will not bind.
Dimension X (Fig. 8) shall be uniform for
all holes so that screws can be used inter-
changeably.
END OF SCREW
SHALL NOT TOUCH
BOTTOM OF HOLE
HOLES LARGE
ENOUGH SO THAT
SCREWS WILL
NOT BIND
FIGURE NO. 8
Screws shall be of sufficient length to properly
engage the threads in the inserted nuts, yet
not so long that /there will be any possibility
of the ends touching bottom.
3.13 Mounting of Abrasive Discs
(Inserted Nut, Inserted Washer
and Projecting Stud Type)
The following illustrations (Nos. 41, 42 and
43) will serve to clarify the differences which
exist between the three types of mountings
for abrasive discs, i.e. the inserted nut type,
the inserted washer type, and the projecting
stud type.
Illustration No. 41
Inserted nut type abrative disc.
Illustration No. 42
Inserted %oa*h*r typ* abrariw disc.
25
2862
C-12
Steel disc wheels (machine face plates) shall
be flat concentric and at a 90° angle as mount*
ed to the machine spindle.
3.14 Mounting of Plate Mounted
Type Wheels
If the plates attached to the wheel are as
thick or thicker than shown in Table 2 page
25, there are no special requirements as to
the diameter and thickness of the steel disc
wheel (machine face plate) on the machine.
If the plates attached to the wheel are thin-
ner than shown In Table 2 page 25, the ma-
chine shall be equipped with a steel disc wheel
(machine face plate) of sufficient diameter and
thickness to provide adequate additional sup-
port. Minimum specifications are given in Ta-
ble 3 for disc grinders.
TABLE 3
MINIMUM THICKNESS OF STEEL DISC WHEELS
FOR MACHINES USING PLATE MOUNTED
WHEELS HAVING THIN MOUNTING PLATES
«0UNTM« PLATE STEEL OtSC MEL
(Machine Face Plate)
P« shall never be less than P * H nor shall the dif-
ference between D and P< exceed 2 inches. It is rec-
ommended that P« equal D wherever practical.
Abrasive Disc
Diameter
D (Inches)
Minimum
Thickness
Pt (Inches)
12 and smaller
%
14 to 16 inclusive
%
17 to 18 inclusive
%
19 to 26 inclusive
%
27 to 86 inclusive
%
Machine face plate and the mounting surface
of the abrasive disc shall be maintained true,
flat and clean. This is the user's responsibility.
Illustration No. 43
Various method* of mounting projecting $tud or ttud
mounted type abrasive disc*.
3.14 Mounting of Plate Mounted
Type Wheels
A typical method of mounting a plate mounted
type wheel is shown in Illustration No. 44.
Note the additional reinforcement given the
abrasive disc, and the mounting plate by the
steel disc wheel (machine face plate).
Even when plate mounted wheels are used, the
machine face plate (steel disc wheel) should
be the full diameter of the wheel where pos-
sible. The original thickness of the machine
face plate should be thicker than minimum in
Table 3 to allow for remachining.to correct for
wear.
26
Illustration No. 44
Plat* moartsd type wtoelt-
2863
C-13
(. )
CODE REGULATIONS
Section 4
SAFETY GUARDS
4.1 General Requirements
All abrasive wheels shall be used only on ma-
chines provided with Safety Guards as defined
in the following paragraphs of this section.
Exceptions: This requirement shall not apply
to. the following classes of wheels and con-
ditions.
(1) Wheels used for internal work while with-
in the work being ground.
(2) Mounted wheels used in portable opera-
tions (see definition Sec 1.4.18 page 15) 2
inches and smaller in diameter.
(3) Types 16, 17, 18, 18R and 19 cones and
plugs and threaded hole pot balls where the
work offers protection.
Note: For additional forms of operator pro-
tection see Appendix A page 87.
4.2 Cup Wheels
Cup wheels (Types 6 and 11) shall be protect-
ed by
(a) Safely. Guards as specified in Sections 4.1
page 27 to 4.10 page 37 inclusive or
(b) Band Type Guards as specified in Sections
4.11 page 40 and 4.12 page 40 or
(c) Special "Revolving Cup Guards" which
mount behind the wheel and turn with it.
They shall be made of steel or other material
with adequate strength and shall enclose the
wheel sides upward from the back for % of
the wheel thickness. The mounting features
shall conform with all Code regulations. (See
section 6 page 52.)
It is necessary to maintain clearance between
the wheel side and the guard. This clearance
shall not exceed 1/16 inch.
(d) Some other form of guard that will in-
sure as good protection as that provided by
the guards specified in (a) and (b) and (c).
Explanatory Information
(NOT PART OF AKBI COM)
Section 4
Safety Guards
4.1 General Requirements
Exceptions to the use of safety guards are
based on the impossibility of using these
classes of wheels with, conventional guards in
place. In these cases, the work often forms a
guard and the mass of the wheel is small. Face
protection is particularly important when us-
ing this class of wheel.
4.2 Cup Wheels
Cup wheels are available with either a thread-
ed or unthreaded hole. Guards are available
for each, of these types. The following illus-
trations Nos. 45, 46 and 47, show the typical
types manufactured. Each is shown mounted
in conjunction with a guard.
nxmcCLttfjut
Illustration No. 45
Type I cup wheel thawing band type guard.
NOTE tELIEF
Illustration No. 46
An unthreaded hole cup wheel and revolving cup
guard attembly. Note relief in guard
which act* at a flange.
NOTE NO KUEF
*7
w
Illustration No. 47
Type II emp wheel thawing threaded prong-anchor
buthing molded into back, and revolving cup
guard. Net* there it no relief between
guanl and wheel buthing .
2864
Ol*
4.3 Guard Exposure Angles
The maximum exposure angles specified in the
following paragraphs, shall not be exceeded.
Visors or other accessory equipment shall not
be Included as a part of the guard when meas-
uring the guard opening, unless such equip-
ment has strength equal to that of the guard.
4.3.1 BENCH AND FLOOR STANDS
The angular exposure of the grinding wheel
periphery and sides for safety guards used on
machines known as bench and floor stands
should not exceed 90 degrees or one-fourth of
the periphery. This exposure shall begin at a
point not more than 65 degrees above the hori-
zontal plane of the wheel spindle. (See Figs.
9 and 10 and section 4.4 page 31.)
4.3 Guard .Exposure Angles
Maximum guard openings are based on the
fact that the line of flight of broken wheel
pieces will be tangential in the direction of
rotation of the wheel. The maximum exposure
angles must not be exceeded.
4.3.1 BENCH AND FLOOR STANDS
Illustration No. 48
An. example of a well-designed guard for a bench
grinder. Note that exposure does not exceed
the 90' maximum stipulated.
FIGURE NO. 9
FIGURE NO. 10
Wherever the nature of the work requires con-
tact with the wheel below the horizontal plane
of the spindle, the exposure shall not exceed
125 degrees. (See Figs. 11 and 12.)
FIGURE NO. 11
FIGURE NO. 12
28
«><*.■
2865
U-L
4.3.2 CYLINDRICAL GRINDERS
4.S.2 CYLINDRICAL GRINDERS
The maximum angular exposure of the grind-
ing; wheel periphery and sides for safety
guards used on cylindrical grinding machines
Bhall not exceed 180 degrees. This exposure
shall begin at a point not more than 65 degrees
above the horizontal plane of the wheel spin-
dle. (See Figs. 13 and 14 and section 4.4 page
31.)
FIGURE NO. IS
FIGURE NO. 14
4.3.3 SURFACE GRINDERS AND
CUTCING-OFF MACHINES
The maximum angular exposure of the grind-
ing wheel periphery and sides for safety
guards used on cutting-off machines and on
surface grinding machines which employ the
wheel periphery shall not exceed 150 degrees.
This exposure shall begin at a point not less
than 15 degrees below the horizontal plane of
the wheel spindle. (See Figs. 15 and 16.)
lfHN.
UfMM
15' ten
FIGURE NO. 15
7
FIGURENO. 16
4.3.4 SWING FRAME GRINDERS
The maximum angular exposure of the grind-
ing wheel periphery and sides for safety
guards used on machines known as swing
frame grinding machines shall not exceed 180
degrees, and the top half of the wheel shall be
enclosed at all times. (See Figs. 17 and 18.)
FIGURE NO. 17
Illustration No. 49
A cylindrical grinding machine employing
a well-designed guard.
4.3.3 SURFACE GRINDERS AND
CUTTING-OFF MACHINES
Illustration No. SO
This surface grinder has a well-designed guard
conforming to basic requirements. The guard is
to designed as to allow easy acctss to the wheel.
4.3.4 SWING FRAME GRINDERS
29
Illustration No. 51
This swing frame grinder has an excellent guard.
Note that the guard encloses at least
1W of the wheel.
2866
l>-2
4.3.5 AUTOMATIC SNAGGING
MACHINES
The maximum angular exposure of the grind-
ing wheel periphery and sides for safety
guards used on grinders known as automatic
snagging machines shall not exceed 180 de-
grees and the top half of the wheel shall be
enclosed at all times. (See Figs. 17 and 18.)
4.3.6 TOP GRINDING
Where the work is applied to the wheel above
the horizontal center line, the exposure of the
grinding wheel periphery shall be as small as
possible and shall not exceed 60 degrees. (See
Figs. 19 and 20.)
£&£c^v
6<f ***£***,
/ \ 1/ \
1
I 1 J
4.3.5 AUTOMATIC SNAGGING
MACHINES
Illustration No. 52
The operator of a temi-automatic nagging machine
easily control* movementa of the grinder in
all direction*.
FIGURE NO. 19
FIGURE NO. 20
4.3.7 PORTABLE GRINDERS
43.7.1 Right Angle Bead or Vertical
Portable Grinder* for tue with
Type 27 and 28 WheeU
Safety guards used on machines known as
right angle head or vertical portable grinders
shall have a maximum exposure angle of .180
degrees, and the guard shall be so located so as
to be between the operator and the wheel dur-
ing use. Adjustment of guard shall be such
that pieces of an accidentally broken wheel will
be deflected away from the operator. (See Fig.
39, page 39.)
4.3.7.2 Other Portable Grinder*
The maximum angular exposure of the grind-
ing wheel periphery and sides for safety
guards used on other portable grinding ma-
chines shall not > exceed 180 degrees and the
top half of the wheel shall be enclosed at all
times. (See Figs. 17 and 18.)
4.3.7 PORTABLE GRINDERS
&>V
■SE&V
f
in
II V _: ^v
>
.;;
ivp^
^<
C^ H
■" / "; V>^
HEfil 1
;__. x
- -W^gj
-:'M*^(
r *3r
^fci^fiffl
• ^S*"*
ILLUSTIUTJOH No. 63
A Type t7 reinforced wheel properly mounted and
i guarded on a vertical portable grinder. I
' • I
80
28 67
0-3
4.4 Exposure Adjustment
4.4 Exposure Adjustment
Safety guards of the types described in Rules
4.3.1 page 28 and 4.3J2 page 29 where the op-
erator stands in front of the opening, shall be
constructed so that the peripheral protecting
member can be adjusted to the constantly de-
creasing diameter of the wheel. The maximum
angular exposure above the horizontal plane
of the wheel spindle as specified in Rules 4.3.1
page 28 and 4.3.2 page 29 shall never be ex-
ceeded, and the distance between the wheel
periphery and the adjustable tongue or the
end of the peripheral member at the top shall
never exceed % inch. (See Figs. 21, 22, 23,
24, 25 and 26.)
Figures 21,-22, 23 and 24 show two satisfac-
tory methods of accomplishing exposure ad-
justment. These sketches are for purposes of
illustration. only. Other methods that agree
with the basic rule are also acceptable. Fig-
ures 25 and 26 show a condition that does not
comply with the requirements.
FIGURE NO. 21
FIGURE NO. 22
CORRECT
Showing adjustable tongue giving required angular
protection for all sizes of wheel used.
FIGURE NO. 23
FIGURE NO. 24
CORRECT
Showing movable guard with opening small enough to
give required protection for smallest size wheel used.
FIGURE NO. 25
FIGURE NO. 26
INCORRECT
Showing movable guard with slxe or opening correct
for full slxe wheel but too Urge for smaller wheels.
31
2868
4.5 Enclosure Requirement
4.5 Enclosure Requirement
4.5.1 SAFETY GUARD
The safety guard shall cover, the spindle end,
nut. and flange projections. The safety guard
shall be mounted so as to maintain proper
alignment with the wheel, and the strength of
the fastenings shall exceed the strength of
the guard.
Exception A — Safety guards on all operations
where the work provides a suitable measure of
protection to the operator, may be so con-
structed that the spindle end, nut, and outer
flange are exposed ; and where the nature of the
work is such as to entirely cover the side of the
wheel, the side covers of the guard may be
omitted.
Exception 6 — The spindle end, nut and outer
flange may be exposed on machines designed as
portable saws. (See paragraph 1.4.17, page 14.)
4.5.1 SAFETY GUARD
Illustration No. 64
An example of a well-detigned guard for a bench
grinder. Note the ride member of the guard it
readily removed for aeeen to wheel.
4.5.2 ADDITIONAL ENCLOSURE
The nature of many operations requires that
adjacent personnel other than the operator be
afforded protection.
Such protection should take the form of an
enclosure which isolates the operation from
the remaining working area.
Heavy wire screen, corrugated iron, steel sheet
or other suitable material may be used in its
construction.
4.5.2 ADDITIONAL ENCLOSURE
IixusnuTioR No. 66
Notice tiu protective ecreen placed around tkt grinding
area. Thi* auxiliary enelotur* itolaU* the grinding
area from the remainder of the plant.
22
2869
0-5
4.6 Material Requirements and
Minimum Dimensions
S«e Figures 33 and 34 and Table 5 page 36
for minimum basic thickness of peripheral
and side members for various types of safety
guards and classes of service.
4.6.1 FOR SPEEDS UP TO
8.000 S.F.P.M.
If operating speed does not exceed 8,000 sur-
face feet per minute cast iron safety guards,
malleable iron guards or other guards as de-
scribed in paragraph 4.6.2 shall be used.
4.6.2 FOR SPEEDS UP TO
16,000 S.F.P.M.
Cast steel, or structural steel, safety guards
as specified in Table 5 page 36 shall be used
where operating speeds of wheels are faster
than 8,000 surface feel per minute up to a
maximum of 16,000 surface feet per minute.
4.6.3 OPTIONAL MATERIALS
If materials other than those listed in Table 5
page 36 are used, the thickness of the periph-
eral and side members shall be such that the
resultant safety guard will be as strong or
stronger than a similar guard constructed ac-
cording to Table 5 page 36.
4.6.4 EXCEPTIONS:
1. For cutting-off wheels* 16 inches diameter
and smaller and where speed does not exceed
16,000 surface feet per minute, cast iron or
malleable iron safety guards as specified in
Table 5 page 36 or other safety guards provid-
ing equal or better protection shall be used.
2. For cutting-off wheels* larger than 16
inches diameter and where speed does not ex-
ceed 14^200 surface feet per minute, fabricated
safety guards as specified in Table 6 page 37
or other safety guards providing equal or bet-
ter protection shall be used.
3. For thread grinding wheels not exceeding
1 inch in thickness cast iron or malleable iron
safety guards as specified in Table 5 page 36
or other safety guards providing equal or bet-
ter protection shall be used.
•See section L4.15 page 14 for cutting-off
wheel definition.
4.6 Material. Requirements and
Minimum -Dimensions
Illustration No. 56
This cutting-off machine it employing a wheel lets than
It inches in diameter and is operating at a ipeed
lest than J 6,000 surface feet per minute
Note excellent cait vron guard.
Illustration No. 67
Thit cutting-off machine hat a icheel larger than 16
inches diameter and it operating at a tpeed lest than
HJtOO surface feet per minute. Note complete
enclosure of tcheel by the fabricated tafety guard.
Illustration No,
Not* tkt heavy east iron safety guard completely ■
tnclomg tkt cutting -off whetL
83
2870
U-6
4.7 Material Specifications
The minimum thickness specifications shown
in Tables 5 page 36 and 6 page 37 are based
on the following: material specifications of the
American Society for Testing Materials.
(a) Gray Iron Castings — A 48-48
(b) Malleable Iron Castings— A 47-52
(c) Steel Castings— A 27-52T
(d) Structural Steel Plate— A 7-53T
(Excluding specifications for rivet
steeL)
Note: Copies of the above listed specifications
may be procured at a nominal price from the
American Society for Testing Materials, Phil-
adelphia, Pennsylvania.
Illustration No. 59
Clote-up view of thread grinding wheel. Note
thm excellent eafety guard.
Other materials having at least equal strength
properties and which lend themselves equally
well to the desired type of construction may
also be used.
4.8 Construction Guide for
Fabricated Guards
Guides for the construction of fabricated
guards of structural steel are shown in Figs.
27 to 32 inclusive and in Table 4 page 35. Two
designs are 6hown. Other designs affording
equal or better protection are also acceptable.
The requirements given in Column A of Table
4 page 35 shall apply also to cast guards and
in such eases, where the tongue is held by
bolts, Column B shall also apply.
4.9 Specifications for Rivets, Bolts,
Welds and Studs for Fabricated
Guards
Table 7 page 38 may be used as a guide in
determining the spacings and size of rivets,
bolts and studs to provide satisfactory con-
nections. Any means of fastening shall be con-
sidered satisfactory if, when assembled, it has
strength at least equal to the tensile strength
of the members being Joined.
4.9 Specifications for Rivets, Bolts,
Welds and Studs for Fabricated
Guards
lUOSTSATION NO. «0
The fabricated eafety guard u eaeUy identifiable bg
the rivett, bolte and velde uted t* tte auemblg.
34
2871
0-7
**«»
narrow otdml
nvrarrio m k .
FIGURE NO. 27
FIGURE NO. 29
FIGURE NO. 31
rosmaicnxMH.
nsrnotemawu.
MJUSTAttt
tonguc —
FIGURE NO. 28
FIGURE NO. 30
FIGURE NO. 32
See Section 34 Page to for Exhaust Provision.
TABLE 4
DIMENSIONAL REQUIREMENTS FOR CONSTRUCTION OF FABRICATED GUARDS
MAXIMUM WHEEL SPEED 10,000 SFPM
A
B
C
D
E
F
G*
H»
Dieawter
•1
Wheel
lach«*
Lmtfta
•1
Th(m
lachn
Dtaaarter
•1 BolU
Mediaa-Girboa
Oaeechea 1 *
Trapered
lachn
SIst al
Aafle Sapperts
Teajce aad
Rnt
lachn
Diiattir
•1
Riveta lor
Sapparu
lachn
Dieantar;
al Eat •*
Coaawtiaa)
Belli
lacbti
Tblckacaa
al
Toa|ue
lacbri
Maxianai
Space be-
tweaa New
Wheal and
Gaard at
Periphery
lachn
Maximaai
laaide
Width el
Gaard
lachn
Under 12
Stt
a
lVixlVixA
4 ea @ U
V4
%
IVi
1% wider than wheel
16
6
K
2 x2 x,V
4n@K
•
If
A
ia
2 wider than wheel
24
6
*
2 x2 xU
6ei@%
%
%
ltt
2 wider than wheel
SO
7
U
2%x2%x%
6et@ H
U
%
1*4
2 wider than wheel
Note: Column D a**ume* low carbon steel (38000 PSI Untile) rivet*. Two rivet* per bar It and Iff" diameter. Four
rivet* per bar Si and SO" diameter. '
'Limitation* tx Column* G and H refer only to guard* the tkapt of which i* timOar to thott thown tie fioui
M and SI.
■re* t7,
85
2872
0-8
00
FIGURE NO. S3
FIGURE NO. 34
Action X-X
TABLE 5
MINIMUM BASIC THICKNESSES OF PERIPHERAL AND SIDE MEMBERS FOR SAFETY GUARDS
I
Maximum
Thickness
Grinding Wheel Diameters
Over 8
Over 12
Over 16
Over 20
Over 24
Over 30
Material Used In
of Grind*
3 to 6 Inches
to 12 inches
to 16 inches
to 20 Inches
to 24 inches
to 30 inches
to 48 inches
Construction of Guard
ing Wheel
A
B
A B
A B
A B
A B
A B
A B
Inches
Inches
Inches
Inches
Inches
Inches
Inches
Inches
lfi 5 S Cast Iron
«rgft (Min. Tensile
■ah a n Strength
%a,l9. 20,000 PSI)
52*8 Class 20
2
Vi
M
% Ms
Vi Vi
Vi Vi
% %
1 Vi
154 1
4
6
Ms
Vi
Ms
Ms
Vi Ms
Vi Ms
Vi Vi
Vi Vi
% Vi
1 H
1 Vi
IVi Vi
IVi Vi
IVi %
IVi 1
IVi IVi
8
% Ms
% Vi
1 %
IVi %
IVi Ti
IVi IVi
10
Vi 'Ms
% Vi
1 Vi
IVi Vi
IVi Ti
IVi IVi
-S&co
16
ltt 1
lVt 1
lMs 1
lMs lMs
IVi IVi
•
20
IVi lVs
IVi IVi
IVi 1%
2 1%
5 o5S Malleable Iron
2
H
Vi
% Me
H H
% Vi
* H
Ti K
1 Ti
4
Ms
M«
M Ms
Vi M
% VI
% %
Ti Vi
IVi Ti
w rSft (Min. Tensile
■ap.w Strength
6
Vi
Ms
H Ms
Vi Vi
% Vi
% %
1 Vi
IVi Ti
8
Vi Ms
Vi Vi
Vi %
% %
1 Vi
IVi Ti
xsfo 60,000 PSI)
5SS.S. Grade 82610
10
% Ms
% VI
VI Vi
% %
1 Vi
IVi Ti
16
'Ms 'Ms
'Ms 'Ms
1 *
IVi Ti
IVi 1
a
20
% Vi
1 Vi
1* %
IVi IVi
2
%
Vi
Ms Ms
% Vi
Vi Ms
% Vi
Vi %
% Vi
4
VI
%
% Vi
Vi Vi
Ms Vi
Vi Vi
Vi %
1 Vi
Steel Castings
V Min. Tensile
o a Strength
Pm 60,000 PSI)
| §■£ Grade V60-30
.it? w
6
8
%
U
Vi H
Vi Vi
% . Vi
'Ms 'Ms
'Ms 'Ms
'Ms 'Ms
IVi Vi
IVi 1
10
1 %
1 %
1 %
1M 'Ms
IVi 1
lMs lMs
16
IK 1%
IVi IVi
IVi IVi
IVi IVi
l'Ms lMs
20
1% IVi
1% IVi
lMs lMs
2Ms l'Ms
Ik
2
VI
Ms
Ms Vi
Ms VI
Ms Vi
Ms Vi
% Ms
Vi %
4
%
Ms
% Ms
% Ms
% Ms
% Ms
Vi Ms
Vi Vi
«5 r< Structural Steel
■g (Min. Tensile
S Strength
6
8
Ms
Ms
Vi Vi
H Vi
Ms Vi
Ms Ms
Ms %
Ms Ms
Ms H.
Ms Ms
Ms %
Vi Vi
Vi Vi
Vi Vi
60,000 PSI)
10
Ms Ms
« %
Vi Vi
H Vi
Vi Vi
Ti *-
16
Ms
% Vi
Vi %
'Ma »Ma 1
'Ms 'Ma
IMa »"'
20
»M« 'Ma
Ti fc
lMs »►..
Rtrjpfimt prwfwe tr tf
■f^l
Action X-X
FIGURE NO. 35
FIGURE NO. 36
TABLE 6
MINIMUM BASIC THICKNESSES FOR PERIPHERAL AND SIDE MEMBERS
FOR SAFETY GUARDS USED WITH CUTTTNG-OFF WHEELS
Material Used
Maximum Thickness
of
Cutting Off Wheel
Speed
Not to
Exceed
Cutting Off Wheel Diameters
in Construction
of Guard
6 to 11
inches
A B
Over 11
to 20 in.
A B
Over 20
to 30 in.
A B
Over 30
to 48 in.
A B.
Over 48
to 72 in.
A B •
Structural Steel
(Min. Tensile
H inch
or less
14,200
SFPM
inches
A A
A A
% %
A A
Strength
60,000 PSI)
ft inch
or less
16,000
SFPM
inches
A H
H %
A %
K A
A %
4.10 Construction Guide for Drawn
Steel Guards
As a guide for the construction of drawn steel
guards for wheel 8 inches diameter and small-
er, Figure 38 and Table 8 page 39 have been
prepared. Other designs affording equal or
better protection are also acceptable.
Special design drawn steel guards for use with
Types 27 and 28 abrasive wheels on portable
machines are shown in Fig. 89 page 39. An
essential feature of design is the lip on the
outer edge which curls inward to deflect pieces
If a wheel Is broken in the 180* arc next to the
operator and to provide necessary strength
with' light sheet steeL
Dimension B shall be sufficient to allow the lip
to curl outside the wheel.
4.10 Construction Guide for Drawn
Steel Guards
Iu.ornu.TTOK No. 61
A typical application of tk$ drown »Uel tafity guard.
87
2874
D-10
GUIDE SHOWING CORRECT FASTENING PROCEDURE
FOR SIDE MEMBERS (See Section 4.8 page 34)
front view, also cross sections showing rouft
SATISFACTORY METHODS Or SECURING -COVER-OS
T/>«»« vi'iw] mil apply to lypmm A,OmC GuOfUS
sxctmn »ia »»'»«■ eeir wrioco
m*TO «*«o** • cove* fct.o ev
NUTS ON CH01 Of MOLTS -
accnen km Sioe v«c«v Onowwo
Srcr>oM *i ei«»» i oot-r rw«<eco
«xre «ncl( o~tr • eort » hclo
• ' HHTJ SN CMOS O' »OtT3-
-#T.r«r.a^
oeerioM »owiMo two THntAoto
("TO «««lt Of LIT- COH* MIO
flr ^«#vs THttowfM c#wos or sri/o»«
-or.— wait ««v
FIGURE NO. 37
TABLE 7
MINIMUM SIZES AND SPACING OF RITETS, BOLTS AND STUDS FOR CONNECTING PERIPHERAL
AND SIDE MEMBERS IN FABRICATED GUARDS OF STEEL PLATE
Thickness
of Pistes being
Connected
For Side Plate (B-l) Attached
to Machine
For Detachable Side Plate
(B-2)
Diameter of
Rivets
Maximum Distance
between Centers
Diameter of Bolts
or Studs'
Maximum Distance
between Centers
Inches
Hand Ms
Ms M Mt
Mt " %
Inches
Mt
tit
tit
Inches
3
3
3
Inches
Ms
Mt
Ms
Inches
6
6
6
Mt " Mt
% - Mt
tit
M
%
3
4
3%
Me
Me
Ms
6
8
7
% ■" *
Mt " Mt
Mt " %
*
Mt
Mt
3
4
4
Ms
Hit
>Mo
6
8
8
* " Ms
lit " %
Mt
Mt
Mt
4
3%
3
Hi.
His
Hit
8
7
6
lit * Ms
H " Ms
Mt
Mt
Mt
8
3
3
Hi.
Hit
Hi.
6
6
6
*Ms " lit
%
3
3
6
6
38
287S
0-11
TYPICAL DRAWN STEEL GUARD. FOR WHEELS
8 Inches Diameter and Smaller (See Section 4.10 page 37)
> mi n t w i —
AMD MATKMIM« *TI«1»ft
t» rtrvmn TMMta mm
<w H-V-X
FIGURE NO. 38
TABLE 8
GUIDE FOR CONSTRUCTION OF DRAWN STEEL. GUARDS FOR WHEEL
2" THICK AND LESS, 8" AND LESS IN: DIAMETER
( )
Material Used in Construction of Guard
Hot Rolled Steel SAE 1008
Maximum Thickness
of
Wheel, Inches
2 to 5 Inches
Above 5 to 8 Inches
Min. Tensile Strength 60,000 PSI
A B
A B
For Speeds Up to (SFPM)
9,600
2
Inches
Inches
A *
12,500
2
A A
A A
17,000
1
A *
% A
FIGURE NO. 89
TABLE 9
DRAWN STEEL GUARD FOR PORTABLE GRINDERS USED WITH TYPES 27 AND 28 WHEELS
Material Used in Construction of Guard
Thickness
of Wheel
Wheel Diameter
Inches
A
Inches
B
Inches
For speeds up to
14.200 SFPM
Hot Rolled Steel
SAE 1008 min. tensile
strength 60,000 PSI
K inches
or less
2to9
*
%
Orer % to
1 inch
7to9
A
1%
89
2376
0-12
4.11 Band Type Guards — General
Specifications
4.11 Band Type Guards — General
Specifications
Band type guards shall conform to the follow-
ing general specifications:
(a) The bands shall be of steel plate or other
material of equal or greater strength. They
shall be continuous, the ends being either riv-
eted, bolted or welded together in such a man-
ner M8 to leave the inside free from projec-
tions.
(b) The inside diameter of the band shall not
be more than 1 inch larger than the outside
diameter of the wheel, and shall be mounted as
nearly concentric with the wheel as practical.
(c) The band shall be of sufficient width and
its position kept so adjusted that at no time
will the wheel protrude beyond the edge of the
band a distance greater than indicated in Ta-
ble 10 page 41; nor the wall thickness (W)
whichever of these dimensions is smaller.
4.12 Construction Guide For Band
Type Guards
As a guide for the construction of band type
guards, Figure 40 and Table 11 page 41 have
been prepared. Other designs affording equal
or better protection are also acceptable.
Illustration No. 62
A p r op erly constructed band type guard. Notice that.
the exposure of the abrative wheel t» in conformance
mzith the requirement* lilted in Table 11.
4.12 Construction Guide For Band
Type Guards
Illustration No. 63
Another example of a well constructed
band type guard.
40
28 77
D-13
1
*o*u»TA«ta
MMKNSION B MOTTO CXCUO Vi"
DIMENSION C UIUC 4.11(C)
FIGURE NO. 40
TABI
EXPOSURE VERSUS
,E 10
WHEEL THICKNESS
Overall Thickness
of Wheel (T)
Inches
Maximum Exposure
of Wheel (C)
Inches
Vi
1
2
S
4
5 and over
1
1%
2
TABLE 11
GUIDE FOR CONSTRUCTION OF BAND TYPE GUARDS
Maximum Wheel Speed 70M SFPM
Minimum
Material
Specifications
Diameter of
Wheel
Minimum
Thickness
of Band
A
Minimum
Diameter
of Rivets
Maximum
Distance
between
Centers of
Rivets
Hot Rolled Steel SAE 1008
Inches
Under 8
8to24
Over 24 to SO
Inches
VI.
%
Inches
7i«
%
Inches
%
1
1*
41
2878
D-14
CODE REGULATIONS
Section 5
FLANGES
5.1 General Requirements
All abrasive wheels shall be mounted between
flanges which shall not be less than one-third
the diameter of the wheel.
Exceptions:
A) Mounted Wheels
B) Portable Wheels with threaded inserts or
projecting studs
C) Abrasive Discs (Inserted Nut, Inserted
Washer and Projecting Stud Type)
D) Plate Mounted Wheels
E) Cylinders, Cup or Segmental Wheels that
are mounted in chucks
F) Types 27 and 28 Wheels (see section 5.4
page 43)
G) Certain Internal Wheels
H) Modified Types 6 and 11 Wheels
(Terrazzo)
I) Cutting-Off Wheels, Types 1 and 27A
(See section 5.1.1 and 5.1.2)
5.1.1 Type 1 Cutting-Off Wheels
Type 1 cutting-off wheels are to be mounted
between properly relieved flanges which have
matching bearing surfaces. Such flanges shall
be at least one-fourth the wheel diameter.
Explanatory Information
(MOT PART Or ANSI CODE)
Section 5
Flanges
5.1 General Requirements
The major stresses produced in an operating
grinding wheel tend to combine and become
greatest at the hole. It is, therefore, important
that stresses due to mounting and driving, act
as far from the hole as practicable.
This is best accomplished by using flanges at
least as. large as those listed in Tables 12, 13,
14, 15, 16, 17, 18 and 19, pages 47, 48, 49, 50
and 51.
Flanges should be at least minimum diameters
specified, identical in diameter and radial bear-
ing surface to avoid cross bending pressures
and stresses in the wheel structure. Cutting-
off wheel flange diameter equal to % the wheel
diameter, is a minimum requirement. In many
cutting-off operations, better results may be
obtained-through the use of larger flanges.
Blotters (Compressible Washers) should al-
ways be used between metal flanges and abra-
sive wheel surfaces for uniform distribution
of flange pressure.
See Sec 5.6 page 44 for exceptions regarding
the use of blotters.
Flanges shall be checked periodically for flat-
ness, burrs or wear.
5.1.2 Type 27A Cutting-Off Wheels
Type 27A cutting-off wheels are designed to
be mounted by means of flat, not relieved,
flanges having matching bearing surfaces and
which may be less than one-third but shall not
be less than one-fourth the wheel diameter.
See Illustration 77 page 56 for one such type
of mounting.
42
2879
5-1
5.1.3 Flange Types
There are three general types of flanges:
Btraight relieved flanges (see Figure 41 page
47); straight unrelieved flanges (see Figure
42 page 48) ; adaptor flanges (see Figures 44
and 45, page 49).
Regardless of flange type used, the wheel shall
always be guarded. (See Bection 4 page 27.)
Blotters shall be used as listed in section 5.6
page 44.
52 Design and Material
Flanges shall be of such design as to satisfac-
torily transmit the driving torque from the
spindle to the grinding wheel.
Flanges may be made of steel, cast iron or
other material of equal or greater strength
and rigidity.
Illustration No. 64
Note the flange* used here are at least % diameter
of wheel; finished all over, and free of rough
or sharp edges.
D
5.4 Uniformity of Diameter
5.3 Finish and Balance
Flanges shall be dimensionally accurate and
in good balance. There shall be no rough sur-
' faces or sharp edges.
5.4 Uniformity of Diameter
Both flanges, of any type, between which a
wheel is mounted, shall be of the same diame-
ter and have equal bearing surface.
Exception: Types 27 and 28 wheels are de-
signed to be mounted by means of a special
adaptor (aee Dins. No. 65 for one type of
adaptor). (Modified types 6 and 11 wheels (ter-
razzo) with tapered K dimension (see section
1.4£0 page 15). Equivalent or better mount-
ing techniques may also be used. (See section
6.15 page 56.) ,
Illustration No. 65
One type of adaptor for a Type £7 wheel.
COCRECT INCORRECT
Illustration Nd. 66 ,*
Proper and improper method* of mounting
wheels having small holes.
43
2880
E-^
5.5 Recess and Undercut
Straight relieved flanges maae according to
Fig. 41 page 47 shall be recessed at least -fa"
on the side next to the wheel for a distance as
specified In the respective tables of dimensions
for these flanges.
Straight flanges of the adaptor or sleeve type
(Figs. 44 and 45 page 49) shall be undercut so
that there will be no bearing on the sides of
the wheel within V4 inch of the arbor hole.
5.6 Contact
5.6 Contact
(A) Flanges shall be designed with respect
to rigidity so that when tightened, the
radial width of bearing surface of con-
tact on the wheel is maintained.
See Table 12 page 47.
Note: See Sec. 5.9 page 46 for Mainte-
nance of Flanges.
(B) Blotters (compressible washers) shall al-
ways be used between flanges and abra-
sive wheel surfaces to Insure uniform dis-
tribution of flange pressure. See Sec. 6.5
page 53.
Exception:
1. Mounted wheels
2. Abrasive discs (inserted nut, inserted
washer and projecting stud type)
3. Plate mounted wheels
4. Cylinders, cups or segmental wheels
that are mounted in chucks
5. Types 27 and 28 wheels
6. Certain Type 1 and Type 27A cutting-
(A) Flanges must be at least minimum diam-
eter specified, identical in diameter and
radial bearing surface to avoid cross
bending, pressures and stresses in the
wheel structure. Flanges must be of suf-
ficient rigidity to resist "springing" from
mounting pressure. This "springing" can
be detected by inserting a feeler gauge
between bearing area of the flange and
the wheel.
(B) Care must be taken to clean the flanges
thoroughly before mounting a wheel. On
certain operations, blotters have a tend-
ency to adhere to the flange.
off wheeb . ,
7. Certain internal wheels
8. Type 4 tapered wheels
9. Diamond wheeb, except certain vitri-
fied diamond wheeb.
10. Modified Types 6 and 11 wheel (terrazzo)
— blotters applied flat side of wheel only.
. CORRECT INCORRECT
iLLUm&TION NO. 67
Proper emd improper method* of mounting
wheele having. large holt*.
44
2S3S
E-3
5.7 Driving Flange
5.7 Driving. Flange
The driving flange shall be securely fastened
to the spindle and the bearing surface shall
run true.
5.7.1 FLANGES. MULTIPLE WHEEL
MOUNTING
When more than one wheel is mounted be-
tween a single set of flanges, wheels may be
cemented together or separated by specially
designed spacers. Spacers shall be equal in di-
ameter to the mounting flanges and have equal
bearing surfaces. (See section 6.7, page 53.)
5.8 Dimensions
The driving flange shall be checked on a regu-
larly maintained schedule for any damage or
run-out.
6.7.1 FLANGES, MULTIPLE WHEEL
MOUNTING
In certain multiple wheel operations where
wheel slippage may be a problem it may be
necessary to key or otherwise securely fasten
both the spacers and the outside flange to the
spindle.
5.8 Dimensions
5.8.1 STRAIGHT FLANGES, RELIEVED
AND UNRELIEVED (See Figs. 41
and 42, Tables 12 and 13, pages 47
and 48)
The tables show minimum dimensions for
straight relieved and unrelieved flanges for
use with wheels with small holes that fit di-
rectly on the machine spindle. Dimensions of
such flanges shall never be less than indicated
and should be greater where practicable.
Illustration No. 68
The proper flange attembliet for Typt 1 and
Type 11 wheelt.
5.8.2 STRAIGHT ADAPTOR FLANGES
HEAVY DUTY GRINDING
Table 14 page 48 and table 15 page 49 shows
minimum dimensions for straight adaptor
flanges for use with wheels having holes
larger than the spindle. Dimensions of such
adaptor flanges shall never be less than indi-
cated and should be greater where practicable.
Note: Inorganic wheels with large holes are
not recommended for snagging. (See
section 9.13 page 68.)
5.8.2 STRAIGHT ADAPTOR FLANGES
HEAVY DUTY GRINDING
Flanges of this type are frequently used with
organic bonded snagging wheels having large
holes.
Inorganic wheels with large holes are not
recommended for- rough snagging operations.
These wheels are not suitable for current
methods of reinforcement and therefore, it is
necessary for the wheels to have small holes
and be used .with straight relieved or tapered
safety flanges.
45
23 82
5AS SLEEVE FLANGES (See Fig. 51)
Table 19 page 51 shows minimum dimensions
for straight flanges that are an integral part
of wheel sleeves which are frequently used on
precision grinding machines. Dimensions of
such flanges shall never be less than indi-
cated and shook! be greater where practicable.
5.8.3 SLEEVE FLANGES
In mounting Jarge hole wheels, it is most im-
portant that equipment and mounting proced-
ures are satisfactory to avoid distorting of
flanges. Careful mounting procedures, using
new clean -blotters and gradual criss-cross
tightening ^of the mounting screws, are im-
portant. Excessive tightening beyond that
necessary to drive the wheel without slippage
results in: abnormal stresses near the hole.
This must be avoided.
5.9 Repairs and Maintenance
AH flanges shall be maintained in good condi-
tion. When the bearing surfaces become worn,
warped, sprang or damaged they should be
trued or ref aced. When ref acing or truing,
care shall be exercised to make sure that
proper relief and rigidity is maintained as
specified in Sections 5.5 and 5.6 page 44 and
they shall be replaced when they do not con-
form to these Sections and Tables 12, 13, 14,
or 19 pages 47, 43 and 51. Failure to observe
these rules might cause excessive flange pres-
sure around the hole of the wheel. This is
especially true of wheel-sleeve or adaptor
flanges.
All flanges should be frequently inspected for
compliance with this rule.
5.9 Repairs and Maintenance
A Standard Inspection Frequency Schedule
should be adopted by each grinding wheel user
depending, on his experience and severity of
use.
Illustration No.
Cheek flange* with etraight edge to be ture they
are not warped or sprung.
46
2883
E-5
u<
'&
c
o
a
•■3
CO
o
t?d
CO
o
w
CO.
I
w
S
o
w
-a
O
g::0
FIGURE NO 41
Driving flange tecured to tptndle. Set Section S.T Page 45.
TABLE 12
MINIMUM DIMENSIONS FOR STRAIGHTJtELIEVED FLANGES
A*
Diameter
of Wheel
B(l)
Minimum
Outside
Diameter of
Flanges
C
Radial Width of
Bearing Surface
D
Minimum
Thickness
of Flange
at Bore
E
Minimum
Thickness of
Flange at Edge
of Recess
Minimum
Maximum
Inches
1
2
3
Inches
%
Hi.
1
Inches
A
K
K
Inches
K
Ms
Inches
V.
H
A
Inches
A
A
A
4
6
6
7
1%
1%
2
2%
K
A
K
K
K
A
K
*
%
K
K
A
A
8
10
12
2%
3%
4
Mt
%
H
%
K
A
K
A
14
16
18
4Hi,
6%
6
K
K
K
%
1
1
' A
A
*
20
22
24
6%
7*
8
H
K
1%
IK
IK
%
*
K
K
A
A
26 >
28
SO
8%
8*
10
*
%
1% -
ltt
1%
*
K
*
36
12
1
2
%
*
42
48
60
72
14
16
20
24
1
1%
1%
IK
2
2
2
2K
%
IK
IK
ltt
K
1
IK
IK
'Flange* for wheel* under X inekee diameter may be unrelieved and ekall be maintained flat and true.
(J) For exception* to minimum outeide diameter of flange*, see paragraph ff J and 6 J J. Dimention* lieted are
rounded to + Jit inehe*.
v_
47
2884
E-6
FIGURE NO. 42
Driving flange oecured to spindle for use only on portable vhetls with threaded inserts or projecting studs.
TABLE 13
MINIMUM DIMENSIONS FOR STRAIGHT UNRELIEVED FLANGES
FOR WHEELS WITH THREADED INSERTS OR PROJECTING STUDS
A
Diameter of Wheel
Minimum Outside
Diameter of Flange
T
Minimum Thickness
of Flange
Inches
Inches
Inches
1 .
S
%
2
1
H
3
1
K«
4
1%
K«
6
1*
%
6
2
%
'NOTE: Mutt be large enough to extend beyond the bushing. • Where prong anchor or
eupback bushing are used, this footnote doe* not apply.
FIGURE NO. 43
TABLE 14
MINIMUM DIMENSIONS FOR STRAIGHT ADAPTOR FLANGE— FOR
ORGANIC BONDED WHEELS OVER 1% INCH THICK*
Wheel Diameter
Wheel
Hole Diameter
B
Minimum
Flange
Diameter
D
Minimum
Thickness of
Flange at Bore
E
Minimum
Thickness of
Flange at Edge
of Undercut
F«
(D-E)
Minimum
Thickness
Inches
Inches
Inches
Inches
Inches
Inches
12
4
6
%
K
%
to
5
7
%
*
H
14
6
8
%
H
%
Larger than
\ <
6
%
%
%
14
5
7
Ti
%
%
to
6
8
%
*
H
18
7
9
%
%
tt
8^
10
%
%
%
Larger than
6
8
1
tt
tt
18
7
9
1
%
%
to
8
/10
1
tt
%
24
\ 10
12
1
tt
%
12
14
1
tt
V*
Larger than 24 to 80
12
15
1
H
%
Larger than 80 to 88
12
,"
IK
%
%
•For wheels under 1M inch thick F dimension ehaU Ml exceed 40% of wheel thickness.
48
2885
6-7
... Wm»\w sm
*$Bfc
FIGURE NO. 44
Central Nut Mounting
Driving flange secured to epindle.
See Section S.7 Page 45.
Blotte
Comer Undercut
FIGURE NO. 45
Multiple Screw Mounting
Driving flange aecured to epindle. See Section 5.7 Page 45.
TABLE IS
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES— FOR :MECH AN ICAL GRINDERS
12*00 8.F.P.M. to 16*00 SJU\M.(1)
Wheel
Diameter
Wheel Hole
Diameter
"B" Minimum
Flange
Diameter
"D" Minimum
Thickness of
Flange at Bore
"E" Minimum
Thickness of
Flange at Edge
of Undercut
F*(D-E)
Minimum
Thickness
20
20
24
30
86
6
8
12
12
12
8
10
15
15
15
1
1%
2
2
2
%
1
1
1
%
1
1
1
0) FLANGES ehall be of eteel, quality SAE 1040 or equivalent, annealed plate, heat treated to R e tS-30.
*For wheel* under 1% inch thick F dimension thall not exceed 40% of wheel thickneee.
FIGURE NO. 46
Driving flange eecured to epindle. See Section 5.7 Page 45.
TABLE 16
MINIMUM DIMENSIONS FOR STRAIGHT ADAPTORiFLANGE— FOR
ORGANIC BONDED WHEELS USED ON SWING FRAME GRINDERS AT
12*00 8J\P.M. to 16*00 SF.P.M.O)
Wheel
Diameter
Wheel Hole
Diameter
"B" Minimum
Flange
Diameter
"D" Minimum
Thickness of
Flange at Bore
"E" Minimum
Thickness of
Flange at Edge
of Undercut
F*(D-E)
Minimum
Thickness
20
20
24
SO
6
8
12
4
8
10
15
15
1
1
IK
1U
%
*
r
P)FLANGES tkatl he of eteel, muaiitn SAE 1040 or equivalent, annealed plmte, heat treated to R K 15-30.
•For wheel* under 1%\ fads ttiefc F Omuneion ehaU not exceed 40% of wheel tkicknee*.
49
2886
E-8
Blotte
Corner Undercut
FIGURE NO. 47
Multiple Screw Mounting
Driving flange secured to spindle. See Section 5.7 Page 45.
FIGURE NO. 48
Central Nut Mounting
Driving flange secured to spindle.
See Section 5.7 Page 45.
o
TABLE 17
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES FOR HEAVY DUTY,
HIGH SPEED FLOOR STAND GRINDERS(l)
12,500 SJJ»J4 to 16,500 SJJPJtt.
Wheel
Diameter
Hole
Diameter
"B" Minimum
Flange
Diameter
"D" Minimum (2)
Thickness of Flange
at Bore
20
24
SO
6 thru 10
12
12
S thru 12
15
15
1
1%
ltt
C) FLANGES $hall be of steel, quality SAE 1010 or equivalent, annealed plate, heat treated to Re 15-30.
OJFor central nut mounting, increase "D" dimension by % in. for each wheel size shown. For flanges not heat
treated, increase "D" dimension by % in. for each wheel size shown.
FIGURE NO. 49
Doable End Spindle
BOLT&KLC
FIGURE NO. 50
Open End Spindle
facrteusmiG
rmcrtausH**:
TABLE IS
MINIMUM DIMENSIONS FOR FLANGES FOR ARBORLESS WHEELS— ORGANIC BOND
Wheel
Diameter
Bolt Circle
Diameter
"B" Minimum
Flange
Diameter
Torque .Used
in Mounting
Ft Lb*.
Mounting Hole Size
Dimension!. (S holes)
(holes equally spaced)
18
20
24
80
8
9%
12
i 8%
( 10%
12
14%
j 80-40
80-40
40-eo
40-60
i /
All mounting holes shall
be 11" inside 'diameter,
with a fiber bushing in
place, not to exceed 11'
outside diameter.
SO
2887
E-9
Blotter!
Corner Undercut
FIGURE NO. 51
Driving flange secured to spindle. See Section 5.7 Page 45.
TABLE 19
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES USED AS WHEEL SLEEVES
FOR PRECISION GRINDING ONLY
Wheel
B
Minimum Outside
D
Minimum Thickness
E
Minimum
Wheel Diameter
Hole Diameter
Diameter of
Flange
of Flange
at Bore
Flange at Edge
of Undercut
Inches
Inches
Inches
Inches
Inches
12 to 14
5
7
%
*
5
7
%
A
6
8
%
A
Larger than 14 to 20
8
10
%
A
10
11%
%
A
12
13%
%
A
8
10
%
%
Larger than 20 to SO
10
11%
*
%
12
13%
tt
%
16
17%
%
%
12
13%
*
%
16
17%
*
%
Larger than 80 to 42
18
19%
%
%
20
21%
K
%
16
20
1
%
Larger than 42 to 60
20
24
1
%
24
29
•
1%
%
Note; These flange* may be clamped together 6y means of a central nut, or by a tenet of bolt* or tome
other equivalent meant of fattening. For hole tixet entailer than ehowmrin this table, use table It.
61
2888
*fe
E-10
CODE REGULATIONS
Section 6
MOUNTING
Explanatory Information
(HOT TAXT Or AMU CODS)
Section 6
Mounting:
O
6.1 Inspection
Immediately before mounting, all wheels shall
be closely inspected and sounded by the user
(ring test, see section 2.3 page. 18) to make
sure they have not been damaged in transit,
storage or otherwise. The spindle speed of the
machine shall be checked before mounting of
the wheel to be certain that it does not exceed
the maximum operating speed marked on the
wheeL
6.2 Arbor Size
Grinding wheels shall fit freely on the spindle
and remain free under all grinding conditions.
A controlled clearance between the wheel hole
and the machine spindle (or wheel sleeves or
adaptors) is essential to avoid excessive pres-
sure from mounting and spindle expansion.
To accomplish this, the machine spindle shall
be made to nominal (standard) size plus zero
minus .002 inches, and the wheel hole shall be
made suitably over size to assure safety clear-
ance, under the conditions of operating heat
and pressure. The spindle diameter should not
be less than listed in section 3.5 page 21 and
Table 1 page 22.
6.3 Surface Condition
All contact surfaces of wheels, blotters and
flanges shall be flat and free of foreign matter.
6.4 Bushing
When a bushing to used in the wheel hole it
shall not exceed the width of the wheel and
shall not contact the flanges. Loose reducing
bushing (not mechanically held) should not
be used with wheels less than % inch In thick-
ness.
6.1 Inspection
A cracked wheel is unsafe
and must not be used. If
any evidence ol damage is
found, the ..information
should be reported to the
manufacturer and ar-
rangements made for in-
spection.
6.2 Arbor Size
Illustration No. 70
"Ring U$f
The machine spindle or adaptor size must be
maintained by the user. Worn or undersize
spindles or adaptors can cause an out-of-
balance condition, contributing to wheel failure.
6.3 Surface Condition
Flanges can be distorted by excessive tight-
ening or burred by dropping and should be
checked periodically. (See section 5.9 page 46
Repairs and Maintenance.) Inspection for for-
eign particles should be made on wheels, blot-
ters and flanges.
Presence of foreign particles in these areas
can result in uneven pressure against the sides
of the wheelxausirig stresses that can lead to
wheel failure.- . Scuffed or damaged blotters
should be replaced.
6.4 Bushing
If a bushing is wider than the wheel in which
it is used it will interefere with proper tight-
ening of the flanges against the wheel.
The power required to drive a grinding wheel
is transferred through the flanges. If this
power is partially or completely transferred
through the bushing, wheel failure may result.
bz
2889
E-ll
6.5 Blotters
When blotters or flange facings of compressi-
ble material are required, they shall cover
entire contact area of wheel flanges.
Highly compressible material such as blotting
paper as normally used should not exceed .025
inches in thickness.
If material of lower compressibility is used,
greater thickness msy be necessary.
Blotters need not be used with the following
types of wheels:
1. Mounted wheels.
2. Abrasive discs (inserted nut, inserted
washer and projecting-stud type).
3. Plate mounted wheels.
4. Cylinders, cups or segmental wheels that
are mounted in chucks.
5. Types 27 and 28 wheels.
6. Certain Type i and Type 27A cutting-ofF
wheels.
7. Certain internal wheels.
8. Type 4 tapered wheels.
9. Diamond wheels, except certain vitrified
diamond wheels.
6.6 Flanges
All abrasive wheels shall be mounted between
flanges which should not be less than one-third
the diameter of the wheel. For exceptions and
further explanation see section S page 42.
6.7 Multiple Wheel Mounting
When more than one wheel is mounted be-
tween a single set of flanges, wheels may be
cemented together or separated by specially
designed spacers. Spacers shall be equal in
diameter to the mounting flanges and have
equal bearing surfaces. When mounting wheels
which have not been cemented together, or
ones which do not utilize separating spacers,
care must be exercised to use wheels specially
manufactured for that purpose. (See section
5.7.1, page 45.)
6.5iBlotters
Blotters are used for several reasons. TIk
tend:to cushion the pressure of the flanges
against high points or uneven surfaces and
distribute the pressure evenly. They prevent
damage to the surfaces of the flanges from the
abrasive surface of the wheel. They provide a
better coefficient of friction than would be ob-
tained between the flange and the wheel, there-
by providing better transmission of the driv-
ing power to the wheel.
Illustration No. 71
Note the blotter between the abrasive
wheel and the flange.
6.61 Flanges
Flanges drive the wheel and must have sv
ficient contact area. They must be of propt
design to prevent distortion causing damaging
stresses in the wheel. -
canto sv
fXCCMIVC TIWTtimN
MCORRECT
Illustration No. 72
The above clearly illustrate* the result* encountered
uiken the spindle end nut is excessively tightened.
6.7 Multiple Wheel Mounting
Soft compressible blotter material is not gen-
erally satisfactory for use as a spacer. Spacers
should be of material rated as of low compres-
sibility such as soft copper or brass.
M
2390
E-12
6.8 Tightening of the Mounting Nut
6.8.1 SINGLE END NUT
The spindle end not shall only be tightened
sufficiently to drive the wheel and prevent
slippage.
6.8.2 MULTIPLE SCREWS
Multiple screw flanges shall be tightened uni-
formly to prevent springing of the flanges
and to insure even distribution of mounting
pressure over entire surface of the flanges.
6.9 Direction and Length of Thread
on Machine Spindle
If flanges are tightened by means of a central
nut, three conditions shall be maintained.
1. Spindles shall be of sufficient length to al-
low a full nut mounting.
2. Threaded portion shall be of sufficient ex-
tent so that the threading shall extend well
inside the flange but not more than half way
within the hole of the wheel.
«
3. Thtdirection of the thread shall be such
that to remove wheel the nut must be turn-
ed the same direction as the wheel rotates
when in use.
6.10 Threaded Hole Wheels
Special consideration other than listed above
must be given to threaded hole wheels of the
following types: 5, 6, 11, 16, 17, 18, 18R and
19.
The machine spindle for such wheels shall be
provided with an unrelieved flat fixed back
flange to allow the wheel to be screwed firmly
against It.
The direction of the thread shall be such that
to remove the wheel it must be turned in the
same direction it rotates when in use.
The length of the spindle shall be such that
it shall not bottom in blind threaded hole type
wheels.
6.8.2 MULTIPLE SCREWS
The gradual -tightening of screws on multiple
screw type flanges by use of a torque wrench
is recommended. The tightening should pro-
ceed from one screw to one diametrically op-
posite and then in a criss cross manner until
sufficient pressure is applied uniformly to
prevent slippage. Care must be taken to avoid
excessive tightening as it may cause springing
of the flanges resulting in wheel breakage.
Torque pressure of 15 to 20 foot pounds is
common with single wheel mounting, how-
ever, some exceptionally severe operations re-
quire greater pressure.
6.9 Direction and Length of Thread
on Machine Spindle
Illustration No. 73
The tpindle u of tufficient length to accommodate
the wheel and flanget.
6.10 Threaded Hole Wheels
When threaded hole wheels are used, as in
cups, cones and plugs, the size and mass of
threaded hole wheels shall be kept within lim-
its which have been found safe by experience
for this mounting procedure.
With this type of mounting, a relieved back
flange shall not be used. If made with a relief,
it can pull the bushing out of the wheel. See
Illustration No. 74.
RELIEVED >ACK
PLATE (FLAME)
Illustration No. 74
M mtntcHp of thrtatUd koU wheel*.
M
2891
t-li
Threaded hole wheel mounting should not be
used with wheeb larger than 6 inches diam-
eter.
Threads in threaded hole wheeb should be of
class 2B fit and should be relieved on the side
fitting against the flange so as to allow the
wheel to be screwed firmly and flat against the
back flange.
6.11 Mounting of Abrasive Discs
(Inserted Nat, Inserted Washer
and Projecting- Stud Type)
For requirements for mounting of abrasive
discs see section 3.13 page 25.
6.12 Mounting of Plate Mounted
Type Wheels
For requirements for mounting plate mounted
type wheeb see section 3.14 page 26.
6.13 Safety Guards
At the completion of wheel mounting the safe-
ty guard should be checked for condition and
adjustment If necessary. AH abrasive wheeb
shall be provided with safety guards. (See sec-
tion 4 page 27 for full information and excep-
tions.)
6.14 Mounted Wheels
The maximum safe operating speed for mount-
ed wheeb shall be determined by the following
factors:
1. Shape and size of mounted wheel.
2. Size of mandrel.
3. Overhang of mandrel
4. Wheel specifications.
(See section 10 page 69 for explanation, and
Tables 23 through 31 pages 72 through 85
for speeds.)
6.13 Safety Guards
Illustration No. 75
Note thvmoell fatigued cup wAeel guard.
6.14 Mounted Wheels
Since the overhang of the mandrel of a mount-
ed wheel is a factor in determining the maxi-
mum allowable operating speed, care should
be taken to assure the overhang conforms to
the limitations set forth in section 10 page 69.
BS
2892
E-14
6.15 Type 27 and Type 28 Wheels
Type 27 and Type 28 wheels, because of their
shape and usage, require specially designed
adaptors. The back flange shall extend beyond
the central hub or raised portion and contact
the wheel to counteract the side pressure on
the wheel in use. The adaptor nut which is less
than the minimum one third diameter of wheel
fits in the depressed side of wheel to prevent in-
terference In side grinding and serves to drive
the wheel by its clamping force against the
depressed portion of the back flange. The vari-
ance in flange diameters, the adaptor nut be-
ing less than one third wheel diameter, and
use of side pressure in wheel operation limits
the use to reinforced organic bonded wheels.
Mounts which are affixed to the wheel by the
manufacturer shall not be reused.
Type 27 and Type 28 wheels shall be used only
with a safety guard located between wheel and
operator during use. (See section 4.3.7.1. page
30 and Figure 39, page 39.)
6.16 Type 27A Wheels
Type 27A cutting-off wheels are designed to be
mounted by means of flat non-relieved flanges,
having matching bearing surfaces not less
than one-fourth the wheel diameter. See Illus-
tration No. 77.
6.15 Type -27 and Type 28 Wheels
Type 27 and 28 wheels are designed for spe-
cific usage on right angle head grinders. Type
27 with -flat outer area is better suited for
notching iand cutting operations as well as
flat area i grinding. Type 28 with saucer-
shaped outer area is better suited for corner
cleaning ?work. When' these wheels are sup-
plied with ji throw-away type adaptor (mount-
ing flange attached by the manufacturer) .the
adaptor should not be reused. It is important
•when mounting Type 27 and Type 28 wheels
that proper contact is made with the larger
back flange.
Flanges -.should be checked for flatness since
a warped flange will cause vibration and pos-
sible wheel failure.
SEAIINO SUtFACE
INCCUKCT
IMMOrtllY MOUNTED
TTPt 37 WHEEL
Illustration No. 76
Type* Z7 and t8 wheel*, became of their ehape,
require tpeeially designed adaptors.
6.16 Type 27A Wheels
Type 27A wheels are designed for cutting-off
on specially designed machines to provide side
relief or clearance when used.
riAT riANcu
il
SHAFT
-
-
3
Illustration
The Trpe t7A Wheel it mounted between flat
non-rrheved flange* of equal bearing nrfaeet.
66
2893
jT
P-8
6.17 Type 2 Cylinder Wheels
6.17 Type 2 Cylinder Wheels
Type 2 Cylinder wheeb have diameter, wheel
thickness and rim thickness dimensions. The
wheel is mounted on the diameter with grind*
ing performed on (wall) rim. The wheel is
chocked or cemented directly to the machine
face plate which Is securely attached to ma-
chine spindle. The machine face plate shall be
flat, concentric and at 90 degree angle as
mounted to machine spindle. (See section 3
page 20, Table 2 page 25 for minimum thick-
ness of machine face plate.) Cylinder wheels
shall be used only on machines equipped with
band type safety guards that conform to gen-
eral specifications outlined in section 4.11 and
4.12 page 40.
ILLURHATION NO. 78
Example* of Type t cylinder vheelt.
6.18 Segments
6.18 Segments
Segments individually chucked in suitable
holding mechanisms to form a grinding unit
shall be mounted in a manner prescribed by
manufacturer of the chucking device. The
safety guard should conform to that used for
Cylinder Wheels, see section 6.17 and specifica-
tions outlined in section 4.11 and 4.12 page 40.
IlLUSTKATION No. 79
A tegmental wheel auembly.
87
2894
F-2
CODE REGULATIONS
Section 7
SPEEDS
7.1 Standard Speeds
7.1.1 STANDARD MAXIMUM SPEEDS
The maximum operating speed of each wheel
shall be established by the wheel manufactur-
er. Table 20 page 59 Indicates maximum sur-
face feet per minnte (SFPM) for various class-
es of wheels. (See Sec. 1 page 1.)
The number of revolutions per minute may be
increased as the diameter of a wheel is re-
duced through wear, provided the original sur-
face feet per minute (SFPM) is never exceed-
ed. (The speed table on page 86 will be help-
ful in converting RPM to SFPM.) It shall be
the user's responsibility not to exceed these
maximnm operating speeds.
7.1.2 MACHINE BUILDER'S
RESPONSIBILITY
All wheels classified for use under Table 20
page 59 of this Code shall be used on grind-
ing machines designed and equipped in accord-
ance with the following Code sections:
a. Sec. 3 page 20 — General Machine Condi-
tions
b. Sec 4 page 27— Safety Guards
c. Sec 5 page 42— Flanges
7.1.3 WHEEL USER'S
RESPONSIBILITY
All grinding wheels shall be used in conform-
ance with instructions given in:
a. Sec 1 page 1 — Definitions
b. Sec 3 page 20 — General Machine
Conditions
c Sec 4 page 27— Safety Guards
d. Sec 5 page 42— Flanges
c Sec 6 page 52 — Mounting
f. Sec 7 page 58— Speeds
g. Sec 9 page 66 — General Operating
Rules
and shall be handled, stored and inspected in
accordance with Section 2 page 16.
Grinding wheels used at speeds higher than
those shown In Table 20 page 59 shall be sub-
ject to the additional requirements outlined in
Section 8 page 62 Special Speeds.
Explanatory Information
(NOT PAST OF AM8I COOK)
Section 7
Speeds
7.1 Standard Speeds
7.1.1 STANDARD MAXIMUM SPEEDS
The maximum operating speeds established in
Table 20 page 59 have proven satisfactory for
the wheels as classified.
Under no condition, should a wheel be oper-
ated faster than the maximum operating speed
established by the manufacturer. This is the
responsibility of the wheel user.
The maximum operating speed as determined
by the manufacturer is dependent on the wheel
shape and strength. The strength of a bonded
abrasive wheel may be defined as the ability
of the wheel to withstand rotational stress.
The maximum operating speed is not neces-
sarily the most efficient grinding speed. Bet-
ter results, are frequently obtained at lower
than maximum operating speeds.
7.1.2 MACHINE BUILDER'S
RESPONSIBILITY
The repeated references to other applicable
Code Sections and Regulations are important.
All designers of grinding machinery should be
familiar with these sections. Their proper ap-
plication has a direct relationship to the safe
use of grinding wheels.
7.1.3 WHEEL USER'S
RESPONSIBILITY
The repeated references to other applicable
Code Sections and Regulations are important.
All users of grinding wheels should be familiar
with these sections. Their proper application
has a direct relationship to the safe use of
grinding wheels.
W
/
2895
F-3
STANDARD MAXIMUM SPEEDS
IN SURFACE FEET PER MINUTE
CUtd-
Type* of Wheels
(See Section 1 for Definitions)
Inorganic Bonds
Organic Bonds
fieatioa
Number
Low
Strength
Medium
Strength
High
Strength
Low
Strength
Medium
Strength
High
Strength
1
Type 1— Straight Wheels— except
classifications 6, 7, 9, 10, 11, 12
and 18 below.
Type 4*— Taper Side Wheels
Types 5, 7. 20, 21. 22. 23, 24, 26. 26
Recessed, Dovetailed and/or
relieved wheels. (Except
Classification 7 below.)
Type 12— Dish Wheels
Type IS — Saucer Wheels
Types 16. 17, 18. 19— Cones and Plugs
01
SFPM
5,500
»ERATING
SFPM
6,000
SPEED £
SFPM
6,600
SHALL N<
SFPM
6,500
>T EXCEE
SFPM
8,000
D:
SFPM
9.500
t
Type 2— Cylinder Wheels including
plate mounted, inserted nut and
projecting stud — Segments
5,000
6,500
6,000
6,000
6,000
7.000
8
Cup Shape Tool Grinding Wheels
(For Fixed Base Machines)
Type 6— Straight Side Cups
Type 11 — Flaring Cups
4,600
6,000
6,000
6,000
7,500
8,500
4
Cup Shape Snagging Wheels
(For Portable Machines)
Type 6— Straight Side Cups
Type 11 — Flaring Cups
4,500
6,500
6,500
6,000
8,000
9,600
S
Abrasive Discs: Plate Mounted
Inserted Nut and Projecting Stud:
Solid or Segmental
5,500
6,000
6,500
5,500
7,000
8,500
Reinforced Wheels Type 1
Max. Dia. 4"
Max. Thickness 'A"
X
X
X
9,500
12.600
16,000
« t
Max. Dia. 10*
Max. Thickness W
X
X
X
9,500
12.500
14,200
All Other Diss, and Thicknesses
X
X
X
9,500
12,500
12,500
Reinforced Wheels— Types 27 and 28
Max. Dia. 9"
Max. Thickness %"
X
X
X
9,500
12,500
14,200
Max. Dia. 9"— Over %" Thick
X
X
X
X
9,600
11,000
7
Type 1 Wheels for Bench and
Prdestal Grinders and
Types 1 and 6 for Surface Grinders
in following sizes only.
7" dia. up to 2" thick and up to
2" hole
5,500
6,326
6,600
6,500
8,000
9,500
8" dia. up to 2" thick and up to
2' hole
5,500
6,325
7,550
6,600
8,000
9,500
Diamond Wheels
Cutttng-Off— IAI, IAXR, lAIRS**
X
X
16,000
X
X
16,000
8
Metal Bond
X
X
12,000
X
X
X
Resin Bond
X
X
X
X
X
9,600
Vitrified Bond
X
X
6,500
X
X
X
9
Cutting Off Wheels Type 1 and 27A
Larger than 16" dia. Including
Reinforced Organic
X
X
X
9,500
12,000
14,200
10
Cutting Off Wheels Type 1 and 27A
16" dia, and Smaller — Including
Reinforced Organic
X
X
X
9,500
12,000
16,000
11
Thread and Flute Grinding Wheels
8,000
10.000
12.000
8,000
10,000
12,000
12
Crankshaft and Camshaft Grinding
Wheels
5,500
8,000
8,500
6,500
8,000
9.500
IS
Type 1 Snagging Wheels 16" dia.
and Larger, Organic Bond, Non
Reinforced Used on Specially
Designed Swine Frame and
Mechanical Grinders
X
•
X
X
X
X
12,500
,14
Internal Wheels— Type 1 and &
Maximum dia. 6"
5,500
8,000
8£00
/ 6,500
8,600
9,500
".Now-standard S*apt tCisattyCeattra $ exclude* emt-off wheel*.
••Sttmdtwd Ditmtmd Whttl Shmpt*. Ftr dtfadiin. ttt ANSI BT+J, iitntifiacUom cede /or Diamond Wheel Shape*.
NtUtFtr «s*s*rtta# turf met fttt ptr •*£»* (SFPM) ta revolutions per minute (RPU) tee Conversion Table
****• "f .
— FkaSaa!**"*" *' **** i °— 6n * rmiM * ckin ' to-***""": Section J^pagt t? — Safety Guard,; teetitn $, page **
2896
59
7.1.4 WHEEL MANUFACTURER'S
RESPONSIBILITY
All wheels shall be tested In accordance with
Table 21. In some cases the shape, size, con-
struction, or use conditions of the wheel make
the speed test Impractical or unnecessary. Ex-
amples of wheeb which need not be speed test-
ed are:
Wheels less than 6" diameter;
Diamond wheels, metal and organic bonds;
Ball grinding wheels;
Segments, segmental disc wheels and disc
wheels;
Regulating wheels (for centerless type
grinders) ;
Mounted wheels.
7.1.4 WHEEL MANUFACTURER'S
RESPONSIBILITY
The test speed subjects a grinding wheel to
significantly greater forces than does the safe
maximum- operating speed. This test estab-
lishes aniadequate factor of safety provided
the wheels are used in accordance with safe
practices-outlined in this Code and have not
been altered, damaged or abused after speed
testing.
The speed test does not justify operation of
the wheeLat higher than the safe maximum
operating speed established by the wheel man-
ufacturer. The maximum safe speed should
never be-exceeded because the additional test-
ed strength covers other normal grinding
stresses.
TABLE 21
WHEEL MANUFACTURERS TESTING SPEEDS
Class of Wheel
Operating Speed
Surface Feet Per Minute
Minimum
Test Factor*
Cuttlng-off Wheeli
All speeds
1.20
All Bonds and Wheel Type*
(Except Cutting-off wheels)
Up to 5,000
1.25
AU Bonds and Wheel Types
(Except Cutting-off wheels)
Faster than 6,000
1.50
* Actual operating speed shall b* multiplied fry this test factor to establish minimum speed at which wheel* *hall
be tested fry the wheel moxu/octttrer.
\
\
60
2897
F-5
12 Speed Check of Machines —
User's Responsibility
The speed of the wheel spindle on grinding
machines shall be frequently cheeked with
snitable Instruments, by competent user per-
sonnel, to make sore that the speed is correct
for the size and type of wheels used. A suit-
able record of such speed checks should be
maintained by the user.
7.2 Speed Check of Machines —
User's Responsibility
It is of special importance that portable air
grinders -should be checked to be sure that
proper air pressure is maintained and that the
machine governor mechanism is clean, in good
operating condition, and functioning properly.
This reference to air grinders is not intended
to overlook the necessity for a regular check
of the speed of wheel spindles on all types of
grindingrmachines. The user should assign
this responsibility to competent personnel us-
ing equipment properly designed for such
speed check purposes. The user should also
keep a regular inspection record of such speed
checks.
7.3 Speed Adjustment Control —
User's Responsibility
7.3 Speed Adjustment Control -
User's Responsibility
If the speed of the machine wheel spindle is
adjustable to compensate for wheel wear, the
speed adjustment shall be under the super-
vision snd control of competent and authorized
persons only.
Certainmachines are designed with adjustable
speeds topermit maintenance of efficient sur-
face speeds by increasing the wheel spindle
speed to: compensate for wheel wear. Special
care must be exercised under proper supervi-
sion, to-be certain that the present operating
speed of : the machine conforms to and does
not exceed the peripheral speed in surface feet
per minute as established for a new wheel.
(See conversion table, page 86.)
61
2898
F-6
( 1
CODE REGULATIONS
Section 8
SPECIAL SPEEDS
8.1 Introduction
This section of the Code Is designed to recog-
nize the importance of continuing development
in the science of grinding with bonded abra-
sive wheels. In such development it is well to
restate the fact that the maximum safe oper-
ating speed marked on a wheel is not neces-
sarily the most efficient grinding speed. Better
results may be obtained at lower speeds. Con-
stant reference to and a knowledge of the
regulations of this Code will be helpful in plan-
ning the development of new equipment.
This section also defines the responsibilities of
the Wheel Manufacturers; the Machine Build-
ers (including one who converts, changes or
otherwise alters a grinding or cut off machine
from the design or purpose originally supplied
by the builder); and the Users of wheels and
machines. It shall be understood that these
areas of responsibility apply to those wheels
and machines operated at Special Speeds in
excess of those listed in Table 20 page 59.
Explanatory Information
(NOT VAST Of ANSI CODE)
Section 8
Special Speeds
8.1 Introduction
The grinding or rcutting-off operations per-
formed with bonded abrasive wheels on many
different types of machines are extremely im-
portant factors in. the industrial productivity
of our country. It.is essential that wheels be
operated and that-machines be designed in ac-
cordance with the -sections of this Code and
that the users of wheels and machines observe
the safety measures applicable to them in this
Code. The cooperation of all three parties
should materially iaid in promoting the safe
use, care and protection of abrasive wheels.
8.2 Requirements for Special Speeds
8.2 Requirements for Special Speeds
Wheels used on special applications at speeds When wheels are used at speeds in excess of
higher than those listed in Table 20 (Section
7 page 58) shall only be used subject to the
following three conditions: (A), (B) and (C),
on effectively guarded, fully protected ma-
chines.
standard speeds - listed in Table 20 page 59
extra precautionashould be observed to assure
safe operation ofclhe abrasive wheel.
8.2.1 CONDITION A— THE WHEEL
MANUFACTURER
The wheel manufacturer shall make certain
that the wheels are of adequate strength, have
been /tested at a suitable overspeed in accord-
ance' with Section 7.1.4 page 60, and bear the
wheel manufacturer** approval of the higher
speed. See Section 1.2.17 page 4 for definition
of The Wheel Manufacturer*'. '
8.2.1 CONDITION A— THE WHEEL
MANUFACTURER
The wheel manufacturer should do such test-
ing as he deems necessary to establish an ade-
quate factor of safety before approving the
wheel for t^ie higher speed. The wheel should
be marked that it has been approved for high
speed application under specific conditions of
use.
62
2899
8.2.2 CONDITION B— THE MACHINE
BUILDER
The machine builder shall make certain at
time of manufacture that the machine is of
suitable design and adequately guarded for the
operation in question. See Section 1.2.18 page
5 for definition of The Machine Builder."
It shall be the machine builder's responsibility
to consult with a wheel manufacturer to de-
termine that a wheel for the special speed ap-
plication can be manufactured and tested in
accordance with the requirements established
in Section 7.1.4 page 60.
8.2.3 CONDITION C— THE USER
The machine user shall make certain that the
machine is operated with approved safety
guards and that the machine is maintained in
a satisfactory condition, as defined in Sections
8 and 4, page 20 and page 27. See Section
1.2.19 page 5 for definition of "the User".
8.3 Wheel Manufacturer's Responsibility
It shall be the wheel manufacturer's responsi-
bility to speed test wheels required for special
speeds and so identify them as follows:
8.3.1 MANUFACTURER'S TEST
It shall be the wheel manufacturer's responsi-
bility to speed test wheels in accordance with
Table 21 page 60 to determine their suita-
bility for safe application. Some wheels that
need not be speed tested are as listed in Sec-
tion 7.1.4 page 60.
8.3.2 IDENTIFICATION
It shall be the wheel manufacturer's responsi-
bility to identify wheels which may be run at
special speeds.
8.4 Machine Builder's Responsibility
It shall be the responsibility of the machine
builder to design and construct those machine
components which are concerned with the
proper and safe operation of the grinding or
cutting-off wheels for the speed and the type
of operation for which the machine is intend-
ed. Particular attention shall be given to the
design of the wheel safety guards, wheel
flanges and wheel mounting spindle as Indi-
cated in the following paragraphs:
8.2.2 CONDITION B— THE MACHINE
BUILDER
The machine builder should be sure the com-
ponents of the machine such as spindle, bear-
ings, guards, flanges, horsepower, etc., are ade-
quate for the grinding operation in question.
Because of design and composition limitations,
certain grinding wheels will not be suitable for
speciaLspeed operations. It is, therefore, im-
portant that the machine builder and grinding
wheel manufacturer cooperate to make certain
a wheel, of adequate strength can be manu-
factured for the operation in question.
8.2.3 CONDITION C— THE USER
The minimum guard requirements of Section 4
page 27. should be met. Where guard data for
the wheel size and operating speed to be used
is not available, requirements should be estab-
lished by actual test. The machine user should
also maintain machines in good condition for
continuing safety (see Section 3 page 20).
8.3 Wheel Manufacturer's
Responsibility
It is important that wheels used at special
speeds be tested and identified for use at the
proper maximum operating speed.
8.3.1 MANUFACTURER'S TEST
Accepted industry practice for speed testing
grinding wheels is outlined in Section 7.1.4
page 60.
8.3.2. IDENTIFICATION
Wheels-approved for special speed applications
shouldhave the special speed indicated on the
wheeIs,z:blotters, accompanying tags, stickers
or container.
8.4 Machine Builder's Responsibility
The machine builder should decide upon the
fitness of the machine for the proposed oper-
ation. ~If it becomes necessary or desirable to
convert, change or alter the machine from the
design or purpose for which it was originally
made by the builder it is important that the
components involved with the use of the abra-
sive wheel be designed in accordance with the
appropriate sections of this Code.
68
2900
F-8
8.4.1 GENERAL MACHINE
CONDITIONS
If an existing machine is to be adapted for use
at a special speed, the general machine condi-
tions of Section 3 page 20 shall be observed
and all component parts of the grinding ma-
chine shall be checked and, If necessary, modi-
fled or adjusted prior to operating at the spe-
cial speed.
8.4.2 SAFETY GUARDS
Grinding and catting off machines shall be
equipped with safety guards in conformance
with the requirements contained in Section 4
page 27 when applicable. When the operation
is beyond the conditions for which guards in
Section 4 page 27 were designed, the machine
builder shall establish by test or calculation
the adequacy of the guard.
8.4.3 FLANGES
Flanges shall be of such design as to satis-
factorily transmit the driving torque from the
spindle to the grinding wheel and conform to
all requirements of Section 5 page 42.
8.5 User Responsibility
The user shall be responsible for the proper
handling, storage, and inspection of grinding
wheels after receipt, in accordance with the
requirements of Section 2 page 16.
It shall be the responsibility of the user to
maintain his grinding equipment in a safe op-
erating condition at all times. Rules of safe
operation of this equipment submitted by the
machine builder shall be observed, as well as
those rules specified In other sections of this
Code.
When an existing machine Is altered by the
user to operate at special speeds, the user shall
assume all of the responsibility of a machine
builder as outlined In Section 3 page 20.
The user shall f uUy inform all operating per-
sonnel that only wheels Identified for operation
at special speeds shall be used and that at no
time shall the maximum speed of the wheel be
.exceeded.
j Protection to operating personnel, as well as
adjacent areas,! shall be m ai n tai n ed at all
times.
8.4.1 GENERAL MACHINE
CONDITIONS
It is important to remember that the grinding
wheel is only one part of the grinding opera-
tion. When the speed of the wheel is increas-
ed, changes may be necessary in the machine
(bearings,: table traverse rates, guards, sens-
ing devices,: power, etc.), so that the entire
unit will operate safely at the special speed.
8.4.2 SAFETY GUARDS
Guards built in conformance with instructions
contained in Section 4 page 27 will have a safe-
ty factor which satisfies good engineering prac-
tice. When speeds in excess of those shown in
Section 4 page 27 are used, either a stronger
guard material or thicker guard members
must be used. The increase in strength should
be sufficient: to maintain the proper safety
factor.
8.4.3 FLANGES
The driving:torque is transmitted from the
spindle through the flange to the wheel. There-
fore, the minimum bearing area specified in
Section 5 page 42 may be inadequate in these
cases. The machine builder should determine
by test that his design is adequate to perform
its intended operation.
8.5 User .Responsibility
The maximum operating speed as determined
by the manufacturer is dependent on the wheel
shape and strength. The strength of a bonded
abrasive wheel may be defined as the ability
of the wheel to withstand rotational stress.
Under no condition should a wheel be oper-
ated faster than the maximum operating Bpeed
established by the manufacturer. This is the
responsibility .of the wheel user.
It is an important responsibility of the user
to maintain grinding machines in a safe op-
erating condition. Machine builders usually
issue rules for the safe operation of their
equipment or fasten warning signs to their
machines calling attention to areas that could
be unsafe if the rules or signs are disregarded.
The user should recognize the importance of
instructing personnel concerning these safety
warnings.
Furthermore, grinding machines are usually
designed to perform certain specific oper-
ations. It is strongly recommended that the
machines be used only on those types of op-
erations for which they are designed.
64
F-9
2901
&5.1 HANDLING, STORAGE AND
INSPECTION
It shmll be the user's responsibility to adhere
to all parts of Section 2 page 16.
SJZJ2 GENERAL MACHINE CONDITIONS
It shall be the user's responsibility to see that
the machine is maintained in such condition
that all requirements of Section 3 page 20 will
contlnae to be adequate.
8.5.1 -HANDLING, STORAGE AND
INSPECTION
It is important that all wheels be handled and
stored .correctly, and inspected carefully. It
is recommended that wheels for special high
speeds be stored in a separate or special area
so that, personnel will be aware they are for
speciaUappIications.
8.6.2.GENERAL MACHINE CONDITIONS
It is important that the maintenance of the
machine be such that the equipment remains
in the aame condition as originally furnished.
8.5.3 SAFETY GUARDS
It shall be the user's responsibility to m«t"Mn
the guards and other protection devices in
good condition. The user shall also make pro-
vision for adequate protection of the personnel
in the operating area. (See Section 4.5.2 page
32.)
&5.4 FLANGES
It shall be the user's responsibility to maintain
flanges in good condition according to Section
5 page 42.
8.5.3 SAFETY GUARDS
When: operating at special high speeds, the
pieces of an accidentally broken wheel will
have more force than those broken at lower
speeds. _It is, therefore, imperative that all
guardsiand protective devices be maintained
in good condition and correctly replaced when
removed. It is also important that adjacent
personnel be protected by barriers, booths or
segregated work areas.
8.6.4: FLANGES
A primary function of flanges is to transfer
the machine power to the abrasive wheel and
grinding operation. It is therefore important
that flanges be maintained as defined in Sec-
tion 5 page 42. Flanges which are worn, warp-
ed or sprung can contribute to wheel breakage.
8JSJ6 MOUNTING
It shall be the users responsibility to see that
all rules of Section 6 page 52 which apply to
the particular operation are observed.
&5.6 GENERAL OPERATING RULES
It shall be the user's responsibility to see that
all General Operating Rules (see Section 9
page 66) that are applicable to the special high
speed operation are observed. It shaU also be
the user's responsibUUy to follow any special
operating instructions furnished by the ma-
chine builder.
8.5.5 JdOUNTING
It is extremely important that all wheels, re-
gardless of speed of operation or the type of
machine involved, be inspected before mount-
ing (see Section 6.1 page 62) and that all rules
for safe mounting practices be observed.
8.6.6GENERAL OPERATING RULES
In some instances the machine builder will
provide special operating instructions and/or
place warning signs on his machines. These,
as well as the general operating rules listed in
Section 9 page 66, should be followed to insure
a safe grinding operation.
66
2902
F-10
CODE REGULATIONS
Section 9
GENERAL OPERATING RULES
Explanatory Information
OTOTVAXT 07 ANSI CODE)
Section 9
General Operating Rules
~)
9.1 Users' Responsibility
Competent persons shall be assigned to the
mounting, care, and inspection of grinding
wheels and machines.
The grinding wheel operator shall be fully
instructed in the use, care and protection of
grinding wheels as defined in this Code.
92 Investigation After Breakage
If a grinding wheel is broken, a careful in-
vestigation shall be made by the user to de-
termine and correct the cause.
9.3 Wheel Speed
Before mounting a wheeL.it shall be deter-
mined that the machine speed does not exceed
the maximum safe operating speed for the
wheel as established by the wheel manufac-
turer. Under no circumstances shall a wheel
be mounted on a machine on which the RPM
exceeds the maximum safe RPM recommended
for the wheeL
9.4 Replacing Safety Guard
After mounting a wheel, care should be taken
to see that the safety guard is properly posi-
tioned before starting the wheeL
9.1 Users* Responsibility
More efficient grinding and a reduction of
wheel breakages -will result when the user
insists that only -personnel with mechanical
aptitude and a good knowledge of the contents
of this Code be assigned to the mounting, care,
inspection and operation of grinding wheels
and machines.
9.2 Investigation After Breakage
Should a grinding wheel be broken in service,
an investigation must be made immediately by
the user to be sure that any conditions at vari-
ance with the requirements contained in this
code and state-laws are corrected. This will
help determine.the cause of the breakage so
that a recurrence of the trouble can be pre-
vented. Assistance in such an investigation
may be obtained irom the machine maker and
the wheel manufacturer.
9.3 Wheel Speed
On some variable speed machines, spindle
speed is governed by an interlock with the
guard or some mother device that allows the
RPM to be increased as wheel diameter de-
creases. Care must be exercised to determine
that such devices are in good working order,
to prevent the possibility of over-speeding and
wheel breakage.
9.5 Starting the Wheel
All grinding wheels shall be run at operating
speed with safety guard In place or in a pro-
tected enclosure for at least one minute before
applying work, during which time no one shall
stand in front of or in line with the wheeL (See
Section 4 page 27.)
9.6 Balance i
Wheels should be rebalanced by the user when
and as often as necessary.
9.5 Startingjthe Wheel
This regulation provides for the safety of the
operator and others should there have been
damage to the wheel or malfunction of the
machine from: any cause.
9.6 Balance
Out of balance wheels set up vibrations which
can result in marred work surfaces, machine
damage and also cause stresses which could
result in wheel failure. On most machines, the
wheels can be rebalanced by truing.
66
2905
F-ll
9.7 Truing and Dressing
9.7 Truing and Dressing
Out of troth wheels shall be trued by a com-
petent person. Wheeb out of balance which
cannot be balanced by truing or dressing:, shall
be removed from the machine. (See Fig. No.
52.)
FIGURE NO. 52
The correct and Incorrect method of dreuins a wheeL
9.8 Wet Grinding
When shutting down a wet grinding operation,
the coolant should first be shut off and the
wheel allowed to rotate until coolant has been
spun out.
The strength of organic bonded wheels can
be affected by coolants. Therefore, the con-
centration and alkalinity of the coolant should
be checked regularly and adjusted accordingly.
9.9 Side Grinding
Side grinding shall only be performed with
wheels designed for this purpose. Grinding
on the flat sides of straight wheels is often
hazardous and should not be allowed on such
operations when the sides of the wheel are
appreciably worn thereby or when any con-
siderable or sudden pressure is brought to
bear against the sides.
910 Lubrication
The machine spindle bearings shall be properly
lubricated to prevent heating which might
causa damage to the grinding wheel
Truing a wheel corrects any out of truth con-
dition in the wheel.
Dressing a wheel alters its cutting action or
shape.
A common method of dressing a wheel used in
off-hand operations is shown in Fig. No. 52.
Note that the dresser should be supported on
a work rest, and that the work rest should
be adjusted away from the wheel so that the
heel of the dresser may hook over the work
rest and be guided by it as the dresser is
moved evenly across the wheel face.
9.8 Wet Grinding
Uneven accumulation of coolant can cause ex-
cessive out of balance in a wheel.
The. concentration and alkalinity of coolants
determines the degree to which they affec'
organic bonded wheels. To avoid injurious a.
feet upon these wheels, it is important to fol-
low the directions of the coolant manufacturer.
9.9 Side Grinding
Peripheral grinding wheels should not be used
for -side grinding because of insufficient sup-
port-io withstand the pressures exerted.
Wheels designed for side grinding such as
abrasive discs are mounted with one flat Bide
against a suitable steel machine plate to safely
withstand side pressure.
9.10 Lubrication
Improperly lubricated spindle beirings will
cause the mounting spindle to expand because
of heat generated thus exerting a stress J-
the arbor hole area.
«7
2904
f--l2
9.11 Check for Wear
9.12 Work Rests
All spindles, adaptors, flanges or other ma-
chine parts on which wheels fit, shall be
periodical]/ inspected and maintained to size.
(See Section S pace 20.)
9.12 Work Rests
On offhand grinding machines (see sec 1.3.6,
page 6) work rests shall be used to support
the work. They shall be of rigid construction
and designed to be adjustable to compensate
for wheel wear.
Work rests shall be kept adjusted closely to
the wheel with a maximum opening of %" to
prevent the work from being jammed between
the wheel and the rest, which may cause wheel
breakage. The work rest shall be securely
clamped after each adjustment. The adjust-
ment shall not be made with the wheel in
motion.
9.13 Large Hole Inorganic Bonded
Wheels
Large hole inorganic bonded wheels (those
with hole in excess of V* of the wheel diam-
eter) should not be used on snagging or other
heavy duty operations.
Jj/Si*. i
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IU.USTRATXON NO. 80
This floor atand grinder ha* a work rett which u
property adjusted. Note the provisions for
work-reft adjustment.
9.13 Large Hole Inorganic Bonded
Wheels
Since the strength of a grinding wheel decreas-
es as its diameter approaches its hole size, it is
not advisable to use large hole inorganic wheels
for rough ^grinding operations since ample
cross section required for strength is not main-
tained throughout the life of the wheel
The fact that large hole inorganic bonded
wheels cannot be manufactured with reinforc-
ing media. near the hole makes them unsuit-
able for rough grinding operations.
68
290S
F-13
CODE REGULATIONS
Section 10
MOUNTED WHEELS
10.1 Maximum Safe Operating Speed
The maximum safe operating speed for mount-
ed wheels shall be determir?? by the follow-
ing four factors:
1. Shape and size of the mounted wheel
2. Size of mandrel
3. Overhang of mandrel (See Fig. 53.)
4. Wheel specifications.
Taking the first three factors noted above into
consideration, look up the maximum safe oper-
ating speed in the corresponding Tables 23
through 31 page 72 through page 85. The
overhangs indicated on the charts are for un-
threaded mandrels. Threaded mandrels will
take the same speed as the % inch overhang
of the unthreaded mandrel
Tables 23 through 31 page 72 through page
85 are set up for medium and high strength
wheels. If the specification indicates a low
strength wheel consult the wheel manufac-
turer for speeds. In no case shall the max-
imum operating speed recommended by the
manufacturer be exceeded.
Exception: Under certain ideal conditions of
truth and balance where the operation is fully
guarded, it may be permissible to operate at
a speed higher than the indicated maximum
safe operating speed, provided the speed
shown in section 10.2 page 70, is not exceeded.
FIGURE NO. M
SketdMi Mnlac vrerkuf 4te
Bet Tabid 23 throve* SL
•0"
Explanatory Information
(HOT PAST Or ANSI CODS)
Section 10
Mounted Wheels
10.1 Maximum Safe Operating Speed
Maximum safe speeds for mounted wheels are
generally limited by the size and shape of the
wheel, the mandrel material and diameter, and
the distance from the mounting chuck to the
abrasive body (overhang).
Due to the size of some mounted wheels, it is
necessary to reduce the size of the mandrel
where it enters the wheel. These are called
tapered mandrels. It will be noted however,
that the resistance- to bending or whipping due
to speed is dependent on the size of the man-
drel at the point where it is chucked, so that
the size of the maffdrcl for speed purposes will
be the diameter of the chucked section.
As threading reduces the effect! 7e diameter of
the mandrel,- mounted wheels with threaded
mandrels require lower operating speeds than
the same size-unthreaded mandrels. Because
these mandrels, are usually short and held
closely in the chuck, the tables give only the
speeds for Vi inch overhang.
Tables 23 to 31 page 72 through page 85 indi-
cate the maximum operating speeds for vari-
ous standard mounted wheels in combination
with several standard mandrel sizes and vari-
ous overhangs.. For many common combina-
tions, the maximum operating speeds can be
read directly from the tables. For interme-
diate wheel and mandrel sizes and overhangs
not shown the maximum operating speed can
be determinedly interpolation.
If it is found ^hat the desired combination of
conditions would result in operation beyond
the maximum speed, a slight change in any one
of the following conditions may be all that is
necessary to eliminate the danger of operating
over the maximum safe speed. Such correc-
tive steps are:
1. For a given shape, reducing the size of the
wheel (either- diameter or thickness, or both)
will raise the maximum speed.
2. Increasing the diameter of the mandrel
will raise pie maximum speed.
3. Reducing the overhang (pushing the man-
drel back into the chuck) will raise the maxi-
mum speed.
2906
F-U
10.2 Special Maximum Operating
Speed
Table 22 shows the maximum operating speed
for rations diameters of mounted wheels. This
speed shall not be exceeded even though high-
er speeds than the maximum safe operating
speed are used under the exception in Section
10.1 page 69.
TABLE 22
SPECIAL MAXIMUM OPERATING SPEEDS
FOR MOUNTED WHEELS
(Sec Exception See. 10.1 pare 69.)
Outside Diameter
of Wheel
Maximum Speed
Inches
(R.P.M.)
%
305,500
K
152,800
%.
122,200
%
101,900
'A*
87,310
%
76,390
%
61,120
"A*
55,560
K
60,930
»%•
47,010
%
43,650
/-~-\
'%•
40,740
(J
1
38,200
ltt
33,950
1%
30,560
1%
27,780
ltt
25,470
1H
23,520
1%
21,830
2
19,100
10.3 Work Pressure
Pressure between the wheel and the work
shall not be so heavy that excessive springing
of the mandrel will result.
10.2 Special Maximum Operating
Speed
Tables 23 to 81 page 72 through page 85 are
based on the several factors which affect the
maximum safe operating speed, however, there
is a limiting speed beyond which no mounted
wheel should be run due to the inherent
strength of the. abrasive body itself. This is
the speed set up in Table 22. No matter what
factors of .wheel size, shape or specification,
mandrel size, overhang, or machine conditions
are changed, the speeds in Table 22 shall not
be exceeded.
IixosntATioM No. 81
A mounted wheel being need to JinuK a die.
10.3 Work Pressure
Work pressure, if excessive, can be the cause
of trouble and a source of danger, through
bending or fracture of the mandrel. If there
is burning of the work or excessive reduction
in mandrel Bpeed, it is quite likely that ex-
cessive pressure is being used. A freer cutting
wheel specification may permit the desired
rate of stock removal without excessive pres-
sure.
f
/
70
2907
TABLES OF MAXIMUM OPERATING SPEEDS
FOR
MOUNTED WHEELS
71
290a G " 2
TABLE 23
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/32" MANDRELS
Wheel
Diam.
Inches
Wheel
Thickness
Inches
Overhanir
AThd.
Overhang — Dimension O*
Shape
No.
1"
1%"
2*
2%"
Mdls.
VV 141
.A
.-is
93.750
53,250
37,500
25,500
16,500
W 142
a
Vv
93,750
53,250
37,500
25,500
16.500
W 143
Vh
Vh
93,750
53,250
37,500
25,500
16,500
W 144
Vh
Vv
93,750
53,250
37,500
25,500
16,500
W 145
Vh
%
88,500
49,500
35.250 |
24,000
15,750
W 146
*
Vx
81,000
43.750
31.500 j
22,500
15.000
W 147
A
A
93,750
53,250
37.500
25.500
16,500
W 148
Hi
A
93,750
53,250
37,500
25,500
16.500
W 149
s
Si
%
90,750
50,250
36,000 :
24.750
15.750
W 150
A
A
93,750
53,250
37,500 j
25,500
16,500
W 151
A
Va
93,750
53,250
37,500 1
25,500
16.500
W 152
A
Vv
83,250
47,250
33,000
23,250
15.000
W 153
A
%
73,500
42,000
28,500
21,000
13.500
W 154
A
%
66,000
38,250
25,500
18,750
12,750
W 155
U
'A
78,000
44,250
30,750
21,750
14.250
W 156
Vv
A
93,750
53,250
37,500
25,500
16.500
W 157
Vx
A
93,750
53,250
37.500
25,500
16,500
W 158
Vv
%
93,750
53,250
37,500
25,500
16,500
W 159
Vx
A
78,000
44,250
30,750
21,750
14,250
W 160
Vv
y+
69,000
42,000
27,750
18,750
13,500
W 161
Vv
A
66,000
39,750
24,750
17,250
12,750
W 162
Vv
%
57,000
34,500
23,250
16,500
11,250
W 165
A
A
93,000
51,750
37,500
25,500
16.500
W 166
A
%
84,750
48,750
28,500
19,500
14,250
W 167
A
'A
61.500
39,000
24,750
18,000
12,000
W 168
A
A
56,250
33,750
22,500
16,500
12,000
W 169
A
%
48.000
28,500
20,250
15,000
11,250
W 170
A
Va
39.750
26,250
16,500
12,750
9,750
W 171
A
•%
27,750
19,500
13.500
10,500
8.250
W 172
%
A
85.500
48.750
33.750
24,000
15.000
W 173
%
V8
71.250
46,500
30.000
19,500
12.750
W 174
%
H
54,000
32,250
21,000
15.000
10,500
W 175
%
%
41.250
24.000
18.000
12,750
9,750
W 176
%
i*
33.750
21.000
15,750
12.000
9.000
■See Figure 53, P»*e 69.
72
2909
0-3
TABLE 24
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8" MANDRELS
Wheel
Diatn.
Inches
Overhanir— Dimension O*
Shape
No.
Wheel
Thickness
Inches
Overhanjr
&Thd.
Mdls.
1"
1%"
2"
2*4"
W 143
W 144
W 145
W 146
•/a
Va
%
%
%
Vi
105,000
105,000
105,000
105,000
64,500
64,500
64,500
64,500
46,650
46,650
46,650
46,650
32,400
32,400
32,400
32,400
21,370
21,370
21,370
21,370
W 151
W 152
W 153
W 154
A
A
A
A
Vi
Va.
%
Vi
105,000
105,000
80,850
70,500
64,500
64,500
52,500
45,600
46,650
46,650
37,500
31,500
32,400
32,400
26,250
21,970
21,370
21,370
17,620
15.220
W 157
W 158
W 159
W 160
%
Va.
Va,
Va,
A
Vz
A
123,000
105,000
92,400
81,370
65,625
64,500
57,370
51,000
47,770
46,650
39,370
34,120
33,150
32,400
27,900
24,000
21,750
21,370
18,900
16,870
W 161
W 162
W 163
W 164
%
Va,
Va,
Va,
A
%
Vi
y*
77,250
68,400
60.000
45,900
45,970
42,370
38,020
30,000
30,900
28,870
26,250
21,750
22,500
20,850
18,750
15,900
16,120
15,000
13,870
11,850
W 165
W 166
W 167
W 168
A
A
A
A
A
Vb
Va,
A
107,400'
96,970
75,000
68,400
62,470
57,000
45,750
41,770
41,250
35,620
31,120
28,650
29,250
25,120
22,500
21,000
20,250
18,000
15,750
15,000
. W 169
W 170
W 171
A
A
A
»/8
%.
61,650
52,500
37,120
37,720
33,000
25,500
27,000
23,020
18,750
19,870
16,650
14,620
14,250
12.600
10,020
W 172
W 173
W 174
W 175
%
%
%
%
A
%
99,370
87,600
69,000
54,000
59,250
53,250
41,250
33,000
41,020
35,250
27,750
24,150
29,250
24,750
20,400
18,000
20,250
17,250
15,000
13,500
W 176
W 177
W 178
%
%
%
1
45,370
33,750
26,250
28,500
23.250
18,750
21,000
17,620
14,250
15,900
13,650
10,870
12,150 '
10,350
8,250
••See Figure 53, Page 69.
73
2910
G-*
(' )
TABLE 24 — (Continued)
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8" MANDRELS
Wheel
Diam.
Inches
Wheel
Thickness
Inches
Overhang
AThd.
Mdls.
Overhang — Dimension O*
Ship*
V
1H"
V
2V4"
W 181
W 182
W 183
W 184
Vb
%
76,390
73,500
51,750
41,020
55,500
43,650
31,870
26,400
36,750
29,100
22,500
19.500
25,500
20,770
17,250
15,000
17,850
15,450
12,900
11,400
W 185
W 186
W 187
%
1
34,500
26,250
20,620
22,500
17,400
13,870
16,870
12,750
10,120
13,120
9,750
7,870
9,900
8,020
6,370
W 190
W 191
W 192
W 193
%
%
%
%
Va
61,120
58,870
43,120
32,250
48,000
34,500
27,370
23,020
31,500
25,120
19,870
16,500
22,650
18,900
15,220
12,520
16,870
14,250
11,620
9,750
W 194
W 195
W 196
%
%
%
y 2
1
29,400
22,120
17,620
19,120
14,250
11,620
13,500
10,120
8,100
10,500
7,650
6,150
8,250
6,150
6,100
W 199
W 200
W 201
W 202
y±
y*
50,930
50,930
88,250
30,600
44,770
33,520
24,370
19,500
30,000
23,850
17,400
13,500
21,750
17,850
13,270
10,120
15,750
13,350
9,970
7,800
W 203
W 204
25,500
18,900
15,900
12,000
10,870
8,400
8,250
6,220
6,600
6,250
W 210
W 211
W 212
W 213
%
7 /a
%
%
y 8
43,650
43,650
33,750
27,000
35,250
27,900
20,400
16,870
25,720
20,400
14,400
11,250
18,900
15,820
11,020
8,250
14,320
12,220
9,000
6,600
W 215
W 216
1
1
y*
88,200
30,520
24,900
18,600
18,000
12,750
13,870
9,620
10,500
7,500
•See Figure 63, Page 69.
74
2911
G-5
TABLE 25
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/16" MANDRELS
Wheel
Diam.
Inches
Wheel
Thickness
Inches
Overhang
AThd.
Mdls.
Overhang — Dimension O*
Shape
No.
1-
1%-
2"
2M~
W 158
W 159
W 160
W 161
Vi
V*
A
%
A
121,500
112.500
103,500
93,750
66.750
63,000
60,000
58,120
48.000
47.250
44.250
42.750
36.000
34,650
33,000
31,870
26.250
25.120
24.000
22.500
W 162
W 163
W 164
Vx
V*
V*
%
89,250
78,750
62,250
56,250
52,500
39,750
41,250
39.000
30.000
30,000
28,870
23.250
21.750
20,620
16.500
W 166
W 167
W 168
W 169
4
A
A
A
A
%
A
%
118.500
100,500
93,000
87,370
65,250
58,500
57,000
55,350
47,250
43.500
42,000
40.870
35.250
32.620
30,750
28.880
25,500
23.250
22,120
21,000
W 170
W 171
A
A
76,500
57,000
47,250
37,500
34300
27,750
25.500
21,750
18,750
15,750
W 173
W 174
W 175
W 176
%
%
%-
%
%
»/2
101,900
98,850
81,750
66,750
65,250
57,750
50.620
43.120
46.500
42.750
36.750
31,350
34,500
32.250
27,750
23,620
24,750
23,250
20,250
17.400
W 177
W 178
1
54.000
42,000
36,000
29,250
26350
22,500
20,250
17,250
15.000
12.900
W 182
W 183
W 184
W 185
76,390
75,000
57,750
49.870
56,250
47.400
39,750
33.750
39370
33370
29350
25300
29,250
24,900
21,750
19,500
.21,750
18,750
15,750
14,620
W 186
W 187
W 188
W 189
Vt
%
1
1&
2
39.000
32.250
22.870
17,250
28.120
23.250
17.620
13.500
21370
18370
13370
10300
15.750
13,500
11,250
8,620
12,000
10,500
W 191
W 192
W 194
%
%
%
14
61,120
61.120
52.500
44.400
1
51.370
43.500
34.870
31.120
36370
30.750
25300
23,400
27.000
23,400
18,750
18,000
20.250
18,000
15,000
13,500
•See Figure S3, Page >
75
2912
G-6
TABLE 25 — (Continued)
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/16" MANDRELS
k ;
•See Figure 53, £a«e 69.
Wheel
Diam.
Inches
Wheel
Thickness
Inches
Overhang
&Thd.
Mdls.
Overhang — Dimension O*
Shape
No.
1"
ltt"
2-
2H"
W 195
W 196
W 197
W 200
W 201
W 202
W 203
%
%
%
%
%
%
%
1
2
Vb
Va,
%
34,500
25,870
14,770
50,930
50,930
45,750
39,750
24,000
18,900
11,770
48,750
37,500
31,500
27,370
18,370
15,000
8,700
33,750
27,900
24,370
20,620
14,250
11,620
7,270
25,500
21,370
18,000
15,900
.10,500
9,370
19,500
16,500
13,870
12,000
W 204
W 205
W 206
W 207
%
%
1
1%
1%
29,250
24,750
19,500
16,500
20,250
17,250
14,250
12,370
15,000
12,750
11,620
9,750
12,000
10,500
9,000
7,870
9,370
8,620
6,750
W 208
%
2
12,750
9,370
7,500
6,000
W 211
W 212
W 213
%
%
7 /8
y*
%
43,650
43,650
42,370
43,650
34,500
28,120
31,870
25,870
21,370
24,000
19,870
16,500
18,370
14,620
12,370
W 215
W 216
W 217
W 218
1
1
1
1
y 8
Vx
%
38,200
38,200
38,200
32,700
38,200
33,750
27,000
22,120
31,120
24,750
19,870
16,870
23,620
19,120
15,750 .
12,900
18,000
14,250
12,000
10,350
W 219
W 220
W 221
W 222
1
1
1
1
i
2
25,120
19,500
13,120
9,000
17,620
14,250
9,370
7,120
12,900
11,150
7,120
5,620
9,900
8,620
6,000
4,870
8,400
7,120
W 225
W 226
W 227
W 228
i%
%
30,560
30,560
27,750
20,620
28,870
22,120
19,120
14,620
21,220
16,350
13,950
11.020
16,270
12,750
10,650
8,770
12,300
10,270
8,700
7,120
W 229
W 230
W 231
W 232
i%
i%
1
1%
1*4
2
16,500
13,270
10,270
7,500
12,000
9,150
7,270
6,000
8,620
6,970
6,000
4,870
6,900
5.700
* 5,100'
4,500
5,770
W 235
W 236
W 237
[ W 238
i%
1%
V*
1
U'i
25,470
25,470
15.750
9,900
24,900
18,750
11,250
6.970
18,900
13,870
7,870
5,470
15,150
10,500
6,370
4,870
i
11,770
8.620
5.620
76
2915
&-T
TABLE 26
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR V A " MANDRELS
Shape
No.
Wheel
Diameter
Inches
Wheel
Thickness
Inches
X"
Overhang
& Thd.
Mdls.
Overhang
— Dimension O*
-
1K-
2"
2%~
3"
,
5"
W176
*
X
81,000
64,379
42,000
33,000
25,500
20,400
13,260
9,550
W177
%
%
66,000
46,500
32,250
27,370
21,000
16,800
10,920
7,860
W178
%
1
55,200
40,500
30,000
23^60
17,250
13,800
8,970
6,460
W179
K
IK
45,750
33,750
25,720
19,720
15,300
12,240
7,960
6,730
W182
hi
X
76,390
62,400
45,750
35,400
27,520
22,020
14,310
10,300
W183
K
%
76,390
54,750
40,500
3U20
24,000
19,200
12,480
8,990
W184
K
%
71,250
47,620
35,020
27,000
20,850
16,680
10,840
7,800
W18S
X
X
61,500
42,000
31,500
24,000
18,370
14,700
9,560
6,880
W186
X
%
51,000
36,370
27,750
21,220
16,120
12,900
8,390
6,040
W187
X
1
40,500
30,000
24,000
18,750
14,250
11,400
7,410
5,340
W188
X
1%
30,370
24,000
18,900
15,000
12,000
9,600
6,240
4,490
W189
X
2
24,000
18,750
15,000
12,150
9,900
7,920
5,150
3,710
W190
X
A
61,120
61,120
48,000
31,600
29,020
23,220
15,090
10,800
W191
X
%
61,120
60,000
44,250
34,500
27,000
21,600
14,040
10,110
W192
X
%
61,120
61,750
38,400
29,770
23,250
18,680.
12,140
8,740
W193
X
%
61,120
45,000
33,370
25,870
20,100
16,080
10,450
7,520
W194
X
X
56,400
39,750
29,400
22,720
17,400
13,920
9,050
6,520
W195
X
X
46,600
32,400
24,900
19,720
15,370
12,300
8,000
5,760
W196
X
1
35,250
27,000
21,300
16,870
13,120
10,600
6,830
4,920
W197
%
2
•
21,000
16,500
12,900
10,870
8,700
6,960
4,520
3,250
W198
%
2X
16,500
12,900
10,870
8,700
7,000
5,600
3,640
2,620
W201
X
X
50,930
60,930
38,100
29,020
22,500
18,000
11,700
8,420
W202
%
%
60,930
44,100
32,400
25420
19,350
15,480
10,060
7,240
W203
*
X
50,930.
36,370
27,750
21,750
16,870
13,500
8,780
6,320
W204
%
X
42,750
30,750
23,250
18,000
14,020
11,220
7,290
5,250
W205
%
1
34,500
25,870
19,500
15,000
12,000
9,600
6,240
4,490
W206
X
IK
28,720
21,520
17,020
13,500
10,800
8,640
6,620
4,050
W207
%
IK
24,000
18,520
14,620
12,000
9,900
7,920
5,150
3,710
W208
X
'-,« /
18/T50
15,370
12,000
9,900
8,000
6,400
4,160
3,000
W209
%
2K \
15,000
12.160
10,500
8,400
6,800
5,440
3,540
2,650
W211
%
X
43,650
43,650
42,900
33,000
26,250
21.000
13,650
9^20
•See Figure 53, Page 69.
77
2914
A- 1
TABLE 26 — (Continued)
GROUP W— (PLAIN WHEELS)
MAX. OPER. SPEED (RPM) FOR %" MANDRELS
Shape
No.
Wheel
Diameter
Inches
Wheel
Thickness
Inches
Overhang
& Thd.
Mdls.
Overhang — Dimension O*
1"
ltt"
2"
2V4-
3"
4"
5*
W212
W213
%
%
43,650
43,650
43,650
40,870
35,100
29,400
27,600
23,400
21,370
18,370
17.100
14,700
11,120
9,560
8,010
6,880
W215
W216
W217
W218
1
1
1
1
38,200
38,200
38,200
38,200
38,200
38,200
38,200
32,770
38,200
33,750
28,500
24,900
33,750
26,250
22,500
19,500
25,500
20,250
17,400
14.850
20,400
16,200
13,920
11,880
13,260
10,530
9,050
7,720
9,550
7,580
6,520
5,560
W219
W220
W221
W222
1
1
1
1
1
1%
2
35,100
25,500
19,120
15,900
24,520
19,120
14,620
12,370
18.750
15,750
12,000
9,750
15,000
12,370
10,500
8,620
12,000
10,500
8,400
6,900
9,600
8,400
6,720
5,520
6,240
5,460
4,370
3,590
4,490
3,930
3,160
2,580
W223
W225
W226
W227
W228
1
IVi
1%
2tt
%
%
%
12,370
30,560
30,560
30,560
30,520
9,900
30,560
30,560
29,620
22,500
8,620
30,560
26,250
22,650
17,850
6,900
24,000
20,100
18,000
14,250
5,500
18,750
15,750
14,100
11,400
4,400
15,000
12,600
11,280
9,120
2,860
9,750
8,190
7,330
6,930
2,060
7,020
5,900
5,280
4,270
W229
W230
W231
W232
1%
m.
ik
1
1%
1V4
2
24,000
20,400
17,620
14,250
18,750
15,900
13,500
10,650
15,370
12,750
10,650
9,000
12,000
10,500
9,000
7.500
9,900
8,400
7,200
6,000
7,920
6,720
5,760
4,800
6,150
4,370
3,740
3,120
3,710
3,150
2,690
2,250
W235
W23S
W237
W238
i%
i%
1%
1%
1
1%
25,470
25,470
22,500
15,600
25,470
25,470
17,620
12,000
25,470
21,750
13,270
9,750
22,720
17,250
10,870
8,250
17,620
13.650
9,520
6,600
14,100
10,920
7,620
5,280
9,170
7,100
4,950
3,430
6,600
5,110
3,560
2,470
W239
W240
W241
1H
IV.
1%
2
2%
3
12,750
10,500
9,000
9,900
8,400
7,250
8,000
6,800
6,000
6,400
5,500
4,800
5,100
4,400
3,900
4,080
3,520
3,120
2,650
2,290
2,030
1,910
1,650
1,460
W242
W243
W244
W245
2
2
2
2
1
2
2tt
19,100
14.500
11,750
9,600
15,950
12,750
10,500
7,250
11,760
9300
7.5O0
6,400
10,000
7,800
6,200
6,300
8,800
6,300
5.030
4,250
7,040
5,040
4,000
3,400
4,580
3,280
2,600
2.210
3,300
2,360
1,870
1,590
W246
2
3
8,250
6,750
5,600
4,600
3.700
2,960
1,920
1,380
*Se« Figure 53, Page 69.
78
29 IS
&-2
TABLE 27
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR %" MANDRELS
Shape
No.
Wheel
Diameter
Inches
Wheel
Thickness
Inches
Overhang
& Thd.
Mdls.
1-
Overhang — Dimension O*
ltt"
2-
2%"
3"
4"
6"
W18S
W186
W187
W188
tt
tt
H
tt
1
ltt
76,390
76,390
76,390
60,740
76,390
72,740
60,000
48,000
63,000
55,500
48,000
37,800
48,000
42,440
37300
30,000
36,740
32,240
28.500
24,000
29,400
25,800
22,800
19300
19,120
16,780
14,820
12,480
13,760
12,080
10,680
8,980
W189
tt
2
48,000
37,500
30,000
24,300
19,800
15,840
10,300
7,420
W194
W195
W196
W197
S
%
tt
%
1
2
61,120
61,120
61,120
42,000
61,120
61,120
54,000
33,000
58,800
49,800
42,600
25,800
45^40
39,440
33,740
21,740
34,800
30,740
26,240
17,400
27,840
24,600
21,000
13,970
18,100
16,000
13,660
9,040
13,040
11,520
9,840
6,600
W198
%
2%
33,000
25,800
21,740
17,400
14,000
11300
7,280
6340
W203
W204
W205
W206
1
1%
60,930
60,930
60,930
60,930
50,930
50,930
50,930
43,040
60,930
46,500
39,000
34,040
43,500
86,000
30300
27.000
33,740
28,040
24,000
21,600
27,000
22,440
19300
17,280
17,560
14,580
12,480
11,240
12,640
10,500
8,980
8,100
W207
W208
W209
K
ltt
2
2%
48,000
37,500
30,000
37,040
30,740
24,300
29,240
24,000
21,000
24,000
19300
16,800
19,800
16,000
13,600
15,840
12,800
10,880
10,300
8,320
7,080
7,420
6,000
5,100
W218
W219
W220
W221
1
1
1
1
tt
%
1
ltt
38,200
38,200
38,200
38300
38,200
38,200
38,200
29340
38,200
37,500
31,500
24,000
38,200
30,000
24,740
21,000
29,700
24,000
21,000
16,800
23,760
19,200
16,800
13,440
15,440
12,480
10,920
8,740
11,120
8,980
7,860
6,300
W222
W223
1
1
2
2%
31,800
24,740
24,740
19,800
19,500
17,240
17340
13300
13,800
11,000
11,040
8,800
7,180
5,720
5,160
4,120
W227
^y 228
W229
W230
1%
m,
IK
1
1%
30,560
30,560
30,560
30,560
30,560
•
30,660
30,560
30,660
30,560
30,560
30,560
25,600
30360
283O0
24,000
21,000
28300
22,800
19,800
16,800
22,660
18340
15,840
13,440
14,660
11,860
10,300
8,740
10,560
8,640
7,420
6300
W231
W232
*
30,560
28300
27,000"
21,300
21,300
18,000
18,000
15,000
14,400
12,000
11320
9,600
7,480
6340
6380
4300
•See Figure 53, Page 69.
79
2916
A- 3
TABLE 27— (Continued)
GROUP W— (PLAIN WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR tf w MANDRELS
Shape
No.
Wheel
Diameter
Inches
Wheel
Thicknesa
Inches
Overhang
AThd.
Mdls.
Overhang — Dimension O*
1"
i
1%"
V
2H-
3-
4"
5"
W236
1%
V,
26,470
26,470
25,470
25,470
25,470
21,840
14300
10320
W237
1%
1
26,470
25,470
25,470
21.740
19,040
15340
9300
7,120
W238
1%
1%
26,470
24,000
19,500
16*00
13300
10,560
6,860
4340
W239
1%
2
26,470
19300
16,000
12300
10300
8,160
6300
3,820
W240
1%
2%
21,000
16,800
13,600
11400
8,800
7,040
4,580
3300
W241
i%
S
18,000
14,500
12,000
9.600
7,800
6340
4,060
2320
W242
2
1
19,100
19,100
19,100
19400
17,600
14,080
9,160
6,600
W243
2
1%
19,100
19,100
19,100
15,600
12,600
10,080
6,560
4,720
W244
2
2
19,100
19,100
15,000
12,400
10,000
8,000
6300
3,740
W245
2
2tt
19,100
14,500
12,800
10300
8,500
6,800
4,420
8,180
W246
2
3
16,600
13,600
11,200
9300
7,400
5320
3,840
2,760
•See Figure 63, Page 69.
80
2917
A-*
TABLE 28
GROUP B— (SHAPED WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/32" MANDRELS
1
%-
Cveihang
AThd.
Mdls.
Overhang — Dimension O*
Shape
No.
Wheel
Diam.
Inches
Wheel
Thickness
Inches
1"
1%-
2-
2%-
B 43
B 44
B 45
B 46
ft
A
A
ft
%
A
A
67,500
57,000
86,250
87,000
41,250
34,500
60,250
52,500
27,000
22,500
35,250
36,750
18,750
16,500
24.000
24,750
12,750
11,250
15,000
16,500
B 47
B 53
B 55
B 63
ft
ft
ft
ft
A
%
ft
A
87,000
49,500
87,000
76,500
52,500
30,750
52,500
46,500
36,750
20,250
36,750
30,750
24,750
14,250
24,750
21,750
16,500
10,500
16,500
14,250
B 64
B 65
B 70
B 71
B 72
ft
ft
%
%
ft
A
ft
ft
ft
ft
87,000
87,000
50,930
61,120
60,750
52,500
52,500
33,750
39,000
35,250
36,750
36,750
21,750
24,750
23,250
24,750
24,750
15,750
17,250
16,500
16,500
16.500
11,250
12,750
12,000
B 73
B 74
B 81
B 82
ft
A
%
ft
ft
A
A
ft
60,750
87,000
50,930
67,500
35,250
52,500
33,750
41,250
23,250
36,750
21,750
27,000
16,500
24,750
15,750
18,750
12,000
16,500
11,250
12,750
B 83
B 84
B 92
B 93
%
A
ft
A
A
A
ft
A
72,750
87,000
67,500
87,000
43,500
52,500
41,250
52,500
27,750
36,750
27,000
36,750
19,500
24,750
18,750
24,750
12,750
16,500
12,750
16,500
B 94
B 95
B 96
B' 97
H
ft
ft
ft
A
A
ft
%
87,000
87,000
87,000
87,000
52,500
52,500
52,500
52,500
36,750
36,750
36,750
36,750
24,750
24,750
24,750
24,750
16,500
16,600
16,500
16,500
B 98
B 104
B 105
B 106
A
ft
ft
ft
%
ft
A
87,000
67,000
86,250
87,000
52,500
34,500
50,250
52,500
36,750
22,500
85,250
36,750
24,750
16,500
24,000
24,750
16.500
11,250
15,000
16.500
B 112
B 113
B 114
B 115
%
ft
ft
ft
ft
ft
37,500
67,500
57.000
87,000
23,250
41,250
34,500
62,500
16,500
27,000
22,500
36,750
12,750
18,750
16,500
24,750
9,000
12,750
11,250
16.500
B 122
B 123
B 124
ft
A
ft
%
A
ft
51,000
86.250
87,000
30,750
60,250
52,500
21,000
85,250
36,750
15.000
24,000
24,750
10,500
15,000
16,500
•See Figure 63, Pag* 69.
81
2918
A- 5
TABLE 29
GROUP B— (SHAPED WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8" MANDRELS
Wheel
Diam.
Inches
Wheel
Thickness
Inches
Overhan*
AThd.
Mdls.
Overhanp — Dimension O*
Shape
No.
1-
l%-
2"
2H~
B 41
%
H
33,750
23,250
17,620
13,650
10,350
B 42
l'a
%
33,750
23,250
17,620
13,650
10,350
B 43
H
A
81,370
51,000
34,120
24,000
16,870
B 44
* T i
%
68,400
42,370
28,870
20,850
15.000
B 45
A
A
104,250
61,870
44,620
30.900
20,250
B 46
>/b
A
105,000
64,500
46,650
32,400
21.370
B 47
%
A
»2
105,000
64,500
46,650
32.400
21,370
B 51
A
•H
45,370
28,500
21.000
15,900
12.150
B 52
%
•Vi.
45,370
28,500
21,000
15,900
12.150
B 53
%
%
60,000
38,020
26,250
18.750
13,870
B 54
V*
'/a
60,000
38.020
26,250
18,750
13,870
B 5f>
Vh
H
105,000
64,500
46,650
32,400
21.370
B 61
%
A
111
38,250
24,370
17,400
13,270
9.970
B 62
V2
%
41,020
26,400
19,500
15,000
11.400
B 63
•/+
A
92,400
57,370
39,370
27.900
18.900
B 64
H
A
105,000
64,500
46,650
32,400
21,370
B 65
%
Vr
105,000
64.500
46,650
32,400
21,370
B 70
%
Vs
50,930
41,250
27,750
20,400
15,000
B 71
%
Vs
61,120
48,000
31,500
22,650
16,870
B 72
V4
Vs
73,500
43,650
29,100
20,770
15.450
B 73
'/2
Vs
73,500
43,650
29,100
20,700
15.450
B 74
s'f
ft
105,000
64,500
46,650
32,400
21,370
B 81
%
A
50,930
41,250
27,750
20,400
15.000
B 82
%
V\
76,390
51,000
34,120
24,000
16,870
B 83
%
A
87,600
53,250
35,250
24,750
17.250
B 84
A
A
105,000
64,500
46,650
32,400
21.370
B 91
%
Vb
34,500
22,500
16,870
13,120
9,900
B 92
%
V*
81,370
51.000
34,120
24,000
16.870
B 93
A
A
105,000
64,500
46,650
32,400
21,370
B 94
H
A
105,000
64.500
46.650
32,400
21,370
B 95
V6
A
105,000
64,500
46,650
32,400
21,370
B 96
%
V*
105,000
64,500
46,650
32,400
-21,370
B 97
V.
— i
105,000
64,500
46,650
32.400
! 21,370
1 i
rr^—. 1 _
-See Figure 63, Page 69.
82
2919
A- 6
TABLE 29 — (Continued)
GROUP B— (SHAPED WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8" MANDRELS
Wheel
Diim.
Inches
Wheel
Thickneis
Inches
Overhang
AThd.
Mdls.
Overhang — Dimension <)•
Shape
No.
1"
l%-
2-
2tt"
B 98
B 101
B 102
B 103
A
%
%
%
V*
n
Vi
A
105,000
33,750
45,370
61,120
64,500
23,250
28,500
41,250
46,650
17,620
21,000
27,750
32,400
13,650
15,900
20,400
21,370.
10,350
12,150
15,000
B 104
B 105
B 106
B 111
A
V*
Yb
A
%
%
A
ii
68,400
104,250
105,000
33,750
42,370
61,870
64,500
23,250
28,870
44,620
46,650
17,620
20,850
30,900
32,400
13,650
15,000
20,250
21,370
10,350
B 112
B 113
B 114
B 115
%
V*
A
A
%
45,370
81,370
68,400
105,000
28,500
51,000
42,370
64,500
21,000
34,120
28,870
46,650
15,900
24,000
20,850
32,400
12,150
16,870
15,000
21,370
B 121
B 122
B 123
B 124
%
A
%
A
45,370
61,650
104,250
105,000
28,500
37,720
61,820
64,500
21,000
27,000
44,620
46,650
15,900
19.870
30,900
32,400
12,150
14,250
20,250
21,370
B 131
B 132
B 133
B 134
%
%
A
%
%
34,500
45,370
54,000
61,650
22,500
28,500
33,000
37,720
16,870
21,000
24,150
27,000
13,120
15,900
18,000
19,870
9,900
12,150
13,500
14,250
B 135
B 136
V*
A
60,000
77,250
38,020
45,920
26,250
30.900
18,750
22,500
13,870
16,120
•See Figure 53, Page 69.
83
2920
A- 7
TABLE 30
GROUP B— (SHAPED WHEELS)
MAXIMUM OPERATING SPEEDS(RPM) FOR 1/4" MANDRELS
Wheel
Diam.
Inchei
Wheel
Thickneas
Inches
Overhang
4Thd.
Mdls.
Overhang — Dimension O*
Shapt
No.
r
ltt"
2"
2tt"
B 41
B 42
B 51
B 52
%
%
%
61,120
61,120
81,000
81,000
46,500
46,500
54,370
54.370
35,250
35,250
42,000
42,000
27,370
27,370
33,000
33,000
21,000
21,000
25,500
25,500
B 61
B 62
B 71
B 72
A
%
y 8
50,930
71,250
61,120
76,390
50,930
47,620
61,120
62,400
38,100
35,020
48,000
45,750
29,020
27,000
37,500
35,400
22,500
20,850
29,020
27,520
B 73
B 91
B 101
B 102
Vt
%
%
%
76,390
61,500
61,120
61,120
62,400
42,000
46,500
64,370
45,750
31,500
35,250
42,000
35,400
24,000
27,370
33,000
27,520
18,370
21,000
25,500
B 111
B 112
B 121
B 131
%
V2
66,000
81,000
76,330
61,500
46,500
64,370
54,370
42,000
35,250
42,000
42,000
31,600
27,370
83,000
33,000
24,000
21,000
25,500
25,500
18,370
B 132
%
%
81,000
64,370
42,000
33,000
25,500
•See Figure 63, Page 69.
84
2921
A- 8
TABLE 31
GROUP A— (SHAPED WHEELS)
MAXIMUM OPERATING SPEEDS (RPM) FORI/4" MANDRELS
Wheel
Wheel
%"
Overhang —
Dimension 0°
snap*
No.
Diam.
Inches
Thickness
Inches
Orei-hang
AThd.
Mdls.
1"
1H"
2"
2Vi"*
S"
A 1
%
2H
19,800
16,500
13,120
10,650
9,000
6,750
A 2
1
VA
38,200
32,620
25,500
20,620
16,870
13.500
A 3
1
2%
16,100
13,080
10,730
8,720
6,710
4,700
A 4
IV*
w*
30,560
24,750
20,250
16.120
13,120
10,500
A 5
%
1%
45,000
33,750
27,000
21,000
16,500
13,500
A 6
y+
1%
39,000
29,700
24,000
18,970
15,000
12,000
A 11
%
2
19,860
15,100
12,000
9,810
8,220
7,020
A 12
it
1%
48,000
35,250
27,370
21,750
17,250
13,500
A 13
i%
1%
33,950
32,250
25,500
20,620
16,500
12,750
A 14
ii
%
55,660
40,500
30,750
24,370
19,500
15,000
A 15
%
1*
72,750
47,620
34,500
26,250
19,870
13,870
A 21
i
1
34,500
26,250
21,000
17,250
13,870
10,870
A 22
%
%
50,930
40,500
30,750
24,370
19,500
15,000
A 23
%
1
39,370
30,370
24,370
19,500
15.000
12,000
A 24
v*
%
76,500
49,500
36,370
27,000
20,250
15,370
A 25
i
1
35,620
27,370
22,120
18.000
14,250
11,250
A 26
%
%
61,120
46,500
35,250
27,750
21,370
15,750
A 31
i%
1
27,780
26,250
21,000
17,250
13,500
10,870
A 32
i
%
88.200
38,200
30,000
24,000
18,900
15,000
A 33
i
Vt
38,200
38,200
30,000
24,000
18,900
15,000
. A. 34
itt
%
25,470
25,470
25,470
. . 21,970
18,000
13,870
A 35
i
%
38,200
38,200
31,500
25,500
20,250
15,900
A 36
i%
%
23,520
23,520
23,520
21,750
17,620
13,870
A 37
i%
%
30,560
30,560
30,560
28.100
22,500
18,000
A 38
i
1
34,500
26,250
21,000
17,020
13,500
10,650
A 39
%
%
47,250
35,250
27,750
22,120
17,250
13,120
•See Figure 63, Page 69.
85
2922
A-9
T
s
CONVERSION TABLE— WHEEL SPEEDS
REVOLUTIONS PER MINUTE FOR VARIOUS DIAMETERS OF GRINDING [WHEELS TO GIVE SURFACE SPEED
IN FEET PER MINUTE AS INDICATED
Dla-
mtur
of
Whtal
Surface Speed in Feet pb Minute
Dia-
meter
of
Wheel
in
4,000
4,600
6300
6300
6,000
6,600
7,000
7,600
8,000
8,500
9,000
9,500
10,000
12,000
12,500
14,200
18,000 116,600
17300
In
Inchn
Revolutions per Minute Revolution! per Minute Revolution! per Minute Revolution! per Minute
Revolution!
per Minute
Inchei
1
2
8
15,279
7,639
6,093
17,189
8.694
5.729
19,098
9,549
6366
21,008
10,504
7,003
22,918
11,459
7,639
24328
12,414
8,276
26,737
13,368
8,913
28,647
14,328
9,549
30,558
15,278
10,186
32,467
16,238
10,822
34,377
17,188
11,469
36,287
18,143
12,096
38,196
19,098
12,732
45,836
22,918
15378
47,746
23,876
16,916
64,240
27,120
18,080
61,116
30,658
20372
63,025
31310
21,010
32,465
21,646
1
2
3
4
5
e
3320
3,066
2,546
4,297
8,438
2365
4,775
3320
3,183
6362
4302
3301
6,729
4384
3320
6307
4,966
4,138
6,686
6348
4,466
7,162
6,730
4,775
7,640
6,112
5,092
8,116
6,494
5,411
8,695
6,876
6,729
9,072
7,268
8,048
9,549
7,640
6,366
11,459
9,168
7,639
11340
9,550
7360
13,560
10,850
9,040
15378
12324
10,186
15,765
12,605
10305
16,235
12385
10320
4
6
6
7
8
2,183
1,910
1,698
2,465
2,148
1,910
2,728
2387
2,122
3,001
2,626
2334
3374
2,865
2346
3,647
8,103
2,758
3320
3,342
2,970
4,092
3,580
3,182
4,366
3,820
3,396
4,638
4,058
3,606
4,911
4,297
3,820
5,183
4,535
4,032
6,456
4,775
4344
6,548
6,729
5,092
6,820
6370
5305
7,750
6,780
6,030
8,732
7,640
6,792
9,005
7,880
7,000
9376
8,115
7316
7
8
9
10
12
14
1,528
1,273
1,091
1,719
1,432
1328
1,910
1,691
1364
2,101
1,761
1,600
2392
1,910
1,637
2,483
2,069
1,773
2,674
2328
1,910
2365
2,388
2,046
3,056
2,546
2,182
3347
2,705
2319
3,438
2,864
2,465
3,629
3,023
2,592
3.820
3.183
2,728
4,684
3320
3374
4,776
3380
3,410
5,425
4,620
3375
6,112
5,092
4366
6300
6350
4,500
6,496
5,410
4,640
10
12
14
16
18
20
955
849
764
1,074
955
869
1,194
1,061
965
1313
1,167
1,050
1,432
1373
1,146
1,552
1379
1341
1,672
1,486
1337
1,791
1,691
1,432
1,910
1,698
1,628
2,029
1,803
1,623
2,149
1.910
1,719
2368
2,016
1.814
2,387
2,122
1,910
2,865
2,646
2392
2385
2,655
2390
3390
3,016
2,715
3.820
3396
3,056
3,940
3,500
3.150
4,060
3,605
3,245
16
18
20
23
84
26
694
637
588
781
716
661
868
"796
734
956
876
808
1,042
1966
881
1,128
1,034
955
1,215
1,115
1,028
1,302
1,194
1,101
1,388
1,274
1,176
1,476
1,353
1348
1,562
1,438
1,322
1,228
1,146
1.074
1,6*9
1,512
1.395
1,736
1,591
1,468
2,084
1,010
1,762
2,170
1,900
1,840
2,465
2,260
2,090
2.776
2,546
2352
2365
2,625
2,425
2350
2,706
2,495
22
24
26
28
30
32
646
609
477
614
673
637
682
637
697
750
700
656
818
764
716
887
828
776
955
891
836
1,023
955
895
1,092
1,018
954
1,169
1,082
1,014
1,296
1,210
1,134
1,364
1,274
1,194
1,637
1,628
1,432
1,705
1,595
1,495
1,940
1,810
1,695
2,182
2.066
1310
2360
2,100
1,970
2320
2,166
2,030
28
30
32
34
36
38
449
424
402
605
477
452
662
630
603
618
583
653
674
637
603
730
690
653
786
742
704
843
796
754
898
848
804
955
902
854
1,011
954
904
1,067
1,007
955
1,124
1,061
1,006
1,348
1,273
1306
1,406
1330
1,260
1,695
1,610
1.430
1,796
1,698
1,608
1,855
1,750
1,660
1310
1305
1,710
34
36
38
40
42
44
382
366
347
430
409
390
478
454
434
625
500
478
673
545
521
620
591
664
669
636
608
716
682
651
764
732
694
812
776
737
860
818
780
908
863
824
956
908
868
1,146
1,090
1,042
1,195
1,140
1,085
1355
1,295
1,235
1,528
1,404
1388
1375
1,500
1,432
1,625
1345
1.475
40
42
44
46
48
63
333
318
288
375
358
324
416
398
360
468
438
395
500
478
432
641
617
468
682
658
603
624
697
639
666
636
576
708
676
612
760
716
648
791
756
683
832
796
720
1,000
956
864
1,040
996
900
1,180
1,130
1,025
1332
1372
1.162
1370
1315
1.189
1,410
1350
1,225
46
48
53
60
72
255
212
287
239
319
265
350
291
387
318
414
345
446
371
478
398
610
424
542
451
674
477
606
504
638
630
774
637
795
665
905
755
1,020
849
1,050
875
1,080
905
60
72
oiven wheel when overapecding, increanet at tht aquar*
Note: "Centrifugal Force," which u tht force that tends to rupture «/»»«" -"7" al SJOO surface feet ver minute is l>9 per
of tk, velocity of that wheel. For example, the centrifugal force m a wheel ™»»W at f h i™%Tu £tYiaUy nly tt per lent
cent greater than in the same wheel running at ifiOO surface feet per mxnute, although the speed t* actually omy zz p r c
greater.
APPENDIX A
(Not Part of ANSI Safety Code B7.1-1970)
Introduction
While not part of this Code, the following relates a number of factors which contribute to the
safe operation of grinding wheels. Safety is everyone's business. «
General Requirements
Abrasive wheels should be used with operator safety in mind and in conjunction with the type
of protective devices most effective for each application.
Classes of Protection Devices
There are two main classes of protection devices: those that protect the operator (A.3.1), and
those that provide protection to others in the work area (A.3.2).
Operator Protection Devices
Safety Guards
The most positive way to protect the operator as well as others in the immediate area is by guard-
ing the wheel effectively. Section 4 (Safety Guards) page 27 explains the provisions necessary
for adequate guarding. A guard protects the operator either by containing or deflecting the pieces
of an accidentally broken wheel. Guards also control sparks and swarf.
Safety Goggles and Face Shields
Because the grinding operation produces sparks and swarf, eye protection is of utmost impor-
tance. Safety goggles or face shields shall be worn at all times in the grinding area. Dust masks
may be required as well.
Protective Clothing
Safety aprons, gloves, safety shoes, and other protective clothing should be worn as required by
the nature of the grinding operation. Well designed protective clothing will allow the operator to
work more efficiently and safely.
Dust Protection
Dust masks may be required in an extremely dusty or contaminated environment.
Work Area Protection
Barriers
In some operations, partitions, walls, or separate grinding booths will provide protection to other
people nearby.
Exhaust Systems
Adequate ventilation and swarf removal should be provided in the grinding area.
Types of Wheel Reinforcing Devices
Cop Back Bushing
The cup.wheel back bushing is a metallic cup with a mountingiroshing which encases the back
and extends from the back partially down the side of the wheetand is an integral part thereof.
This device, while not providing the same protection as a stationary guard, does reinforce the
wheel while in use.
Steel Rings
Steel rings are generally used in large hole organic bonded snagging wheels. They are molded into
the wheel and serve to reinforce the wheel as it approaches discard size.
Fiberglass and Filament Reinforcing
Fiberglass and filament reinforcing is molded on or into organic bonded wheels. This type of re-
inforcing increases the ability of wheels to withstand operational forces when cracked.
Wire or Tape Winding /
Certain types of wheels are wrapped with bands of wire or (tape. Such wrapping acts as a rein-
forcement of the wheel and can also serve to protect the wheel during handling, shipping, and
storage.
87
2924 A-ll
INDEX
This index is not part of the American National Standard Safety Code
for The Use, Care, and Protection of Abrasive Wheels, B7.1. Its object
is to aid the reader in finding references to key words and subjects.
A
Abrasive Disc Wheels,
Including Segmental Discs See "Wheel Types"
Abrasive Wheel— Definition 1
Adaptor Flanges 43 thnl 46 , 48 thru 61
Adaptors 13.24,62,66,68
Adaptors — For Types 27 & 28 Wheels . . . . 13. £6
Arbor Holes See "Holes"
Arborless Wheels 60
Automatic Snagging Machines
(Mechanical Grinders) .30, 49, 69
B
»*!f "£*• ,. W • , 43, 52, 66, 67, 69
Ball Grinding Wheels .... . 60
Band Type Guards [ 27,40,41,67
Bench Grinders . . 28, 32, 69
Bins, Storage 16, 17, 18
S ii te ™. * « 18, 43, 44, 46, 62, 53
Bolts, Guard Construction 34, 36, 38, 40
Boxes, Storage 16, 17, 18
Bushings 4, 11, 15, 24, 27, 48, 52, 64, 65
C
Camshaft Grinding Wheels 69
Centerless O.D. Grinding (Including Wheels) . . . 5. 8
Chucks 1.4,42,57
Coolants 67
Cone Wheels ! ! See "Wheel Types"
Coping & Coping Wheels 6. 14
Crankshaft Grinding Wheels 69
Cup Back Bushings 2. 4
Cup Wheel Guards 27
Cup Wheels See "Wheel Types"
Cutting Off (Including Wheels) 6, 13, 14, 17, 18, 29, 33, 37, 42, 44,
63, 66, 59, 60, 62, 63, 64, 69
Cylinder Wheels See "Wheel Types"
Cylindrical O.D. Grinding (Including Wheels) . . . 6. 8, 29, 31
D
Definitions 1 thru 15, 58
Depressed Center Wheels See "Wheel Types"
Diameter of Wheels, Limiting 21, 66
Diamond Wheels 1, 14, 44, 53, 59, 60
Disc Wheels, Steel 25. 26
Discs See "Abrasive Disc Wheels"
Dish Wheels See "Wheel Types"
Double Recessed Wheels See "Wheel Types"
Drawers, Storage 16, 17, 18
Drawn Steel Guards 37, 39
Driving Flanges 45, 47 thru 50
Driving Torque 43, 50, 64
E
Enclosure Requirements for Guards 32
Enclosures, Other than Guards 32, 66
Exhaust Provisions 20
Exposure Adjustment of Guards 30, 31
Exposure Angles of Guards 28, 29, 30
F
Fabricated Guards 34, 35, 36, 37, 38
Flanges 1, 3, 4, 8 thru 15, 21, 23, 24, 32,
^ , „ *2 thru 66, 68, 63, 64, 65, 68
Flaring Cups See "Wheel Types"
Floor Stand Grinders 28, 50
Flute Grinding Wheels 69
G
General Machine Conditions 20 thni 26, 68, 64, 65
General Operating Rules 68, 65 thru 68
Grinding Surface or Face 2. 8 thru 13
Grinding Wheel See "Abrasive Wheel"
Guards See "Safety Guards"
H
Handling 1. 16. 64, SJ
Heavy Duty Grinding 45,48,49,60,6*
HumW : :::::: : : * &■ aau 15 ' 24thrn «• «.«tiws2, u. k.i
292S
A- 12
Identification of Wheels
Inorganic Bonded Wheels
Inserted Nat Discs
Inserted Washer Discs
i ns y 3 jj
Internal Grinding (Including Wheels)
Large Hole Inorganic Wheels
Limitations of Wheel Shapes
Limiting Wheel Diameter .
Liquids
Lubrication, Bearings .
Machine Builder, Including Responsibi
Machine Face Plates .
Machine Spindles ....
Machines, General Conditions of .
Mandrels
Manufacturer of Machines .
Manufacturer of Wheels
Mechanical Grinders
(Automatic Snagging Machines)
Metal Bonded Wheels .
Mounted Wheels .
Mounting
ities
'Mounting Nut
Mounts, Spindle .
Mounts — For Types 27 and 28 Wheels
Multiple Screw Flanges
Multiple Wheel Flanges
Multiple Wheels .
Off-Hand Grinding
Operating Rules, General
Operating Speeds, Maximum
Organic Bonded Wheels
Overhang of Mandrels .
Plate Mounted Wheels .
Plug Wheels ...
Portable Grinding (Including Wheels)
Portable Saws
Power ....
Precision Grinding (Including Wheels)
Pressure, Work
Projecting Stud Type Discs
Protection, Other than Guards
Racks, Storage
Recessed Wheels ,
Recess of Flanges
Reducing Bushings
Regulating Wheels
Reinforced Wheels
Relieved Wheels .
Resin Bonded Wheels .
Rests, Work ....
Revolutions per Minute (rpm)
Revolving Cup Guards .
"Ring" Test ....
Rivets, Guard Construction .
Rubber Bonded Wheels
Safety Tapered Flanges
Safety Guards, Including Dimensions,
Maintenance, etc. .
Saucer Wheels ....
Saw Gumming (Including Wheels)
Scope
Screws, Mounting ....
Segmental Disc Wheels
Segments (Segmental Wheels), .
Shall— Definition . . . i ■
Shapes of Wheels . . . | .
Shelves, Storage ....
Shellac Bonded Wheels
Should— Definition
Side Grinding ....
Silicate Bonded Wheels
Sleeves, Wheel ....
Sleeve Typa Flanges .
Materials,
M
S
62,63
1.8, 15,45, S9, 68
See "Wheel Types"
See "Wheel Types"
ID Id if e* HO «4 « ««
.3, •«, Q3, W— , --W, ■*-., *ru>, ««*.
6, 27, 42, 44, 63, 59
45,68
7 thru 13
21,66
16
67
a-
5, 58, 62, 63, 64
4, 25, 26, 57
See "Spindles"
20 thru 26, 68, 61, 64, 65, 66
55, 69, 70, 72 thru 85
See "Machine Builder"
See *« Wheel Manufacturer"
30, 49, 59
1, 14, 59
15, 27, 42, 44, 53, 55, 60, 69 thru 85
1, 8 thru 14, 21, 23, 25, 26, 32, 42, 43, 44, 45,
49 thru £8, 65, 66
13. 23, 32,49, 50, 54, 56
24
13. 42, 43, 44, 53, 56
49, 60, 51, 54
45,53
45,53
6, 21, 67
58, 65 thru 68
See "Speeds"
1 thru 4, 13, 14, 15, 18, 48, 49, 50, 56, 59, 67
55, 69, 72 thru 85
8, 26, 42. 44, 53, 55
See "Wheel Types"
6, 27, 30, 37, 39, 42, 59
32
20, 52, 53, 65
6, 7, 8, 9, 10, 61
70
See "Wheel Types"
32, 66
16, 17, 18
See "Wheel Types"
43, 44. 45, 47
4.52
60
1. 2, 13, 14, 56, 59
See "Wheel Types"
1, 59
21,68
3, 58, 69 thru 86
27
18,19,52
34, 35, 38, 41
1
8
1, 2, 4, 14.20, 21, 27 thru 41, 43,
55 thru 58, 63 thru 66
See "Wheel Types"
7,17
1
25, 49, 50, 54
4, 59, 60
4, 42, 44, 53, 57, 59, 60
See "Wheel Types" |
16.17
1
1
56, 57, 67
1,19
24. 51, 52
3, 44. 46, 51
2926
89
,.- — V.
( }
s
Slotting 7
Small Wheel* 17, 18
Snagging (Including Wheels) , 7. 8. 30, 45, 49. 69. 68
Spacers, Multiple Wheel -45, S3
Special Speed* See "Speeds"
Speeds:
Conversion Table (rpm to sfpm) 8G
General 3,21.22.33,35,36,37.30,41,49,
60. 52, 55. 58. 60. 61, 66
Special Speed* 68, 62 thru 65, 69, 70
Standard Maximum Speeds 68 thru 61, 69 thru 85
Spindles 4. 11. 15, 21 thru 25, 28, 29, 32, 45, 49,
50, 52, 64, 57, 61, 63, 67. 68
Spindles— Direction of Threads 23, 24
Starting the Wheel fiC
Steel Disc Wheels 25, 26
Steel Rings 2, 3
Storage 1, 16. 17, 18, 64. 65
Straight Cup Wheels See "Wheel Types"
Straight Relieved Flanges 42 thru 45, 47
Straight Unrelieved Flanges 11,15,24,42.43,45,48
Straight Wheels See "Wheel Types"
Strength of Wheels 16,58,60,62,63,64,68,69
Stresses 20, 42, 44, 62, 53, 58, 60, 64, 66
Studs 34, 38
Surface Feet per Minute (sfpm) 3,21,33,35,36,37,39,41,49.50,58.69,86
Surface Grinding (Including Wheels) . : . . . 7, 8. 29, 59
Swing Frame Grinders 29, 49, 59
T
Tapered Safety Flanges 8
Taper Sided Wheels See "Wheel Types"
Tape Winding 2, 4
Temperature 16, 17, 18
Terrazto Wheels 15, 42, 43, 44
Test Speed. Wheel Manufacturer 60, 63
Threaded Bushings 4, 11
Threaded Hole Cup Wheels 15, 48, 54. 55 t
Threaded Hole Wheels 11,15,24,27,48,54,65
Thread Grinding Wheels 33, 59
Tool Grinding (Including Wheels) 7, 59
Tongues of Safety Guards 35
Top Grinding 30
Torque 43, 50, 64
Trucks 16
Truing 67
Tuck Pointing (Including Wheels) 7, 14
Types of Wheels See "Wheel Types"
U
Undercut of Flanges 44, 48 thru 51
Usage Definitions 5, 6, 7
User of Wheels and Machines,
Including Responsibilities 5, 16 thru 19, 52, 58, 61 thru 70
V
Variable Speed Machines 21. 61, 66
Vitrified Bonded Wheels 1, 19, 53, 59
W
Water 16
Wear, Check for 68
Welds, Guard Construction 34, 38, 39. 40
Wet Grinding 67
Wheel Manufacturer. Including Responsibilities ... 4, 68, 60, 62, 63
Wheel Manufacturer's Test 60, 63
Wheel Speeds See "Speeds"
Wheel Strength 16, 58, 60, 62, 63, 64, 68, 69
Wh*el Types — Definitions and Limitations .... 1 thru 13
Type 1— Straight Wheels 8, 14. 17. 18. 42. 44, 53, 59
Type 2— Cylinder Wheels 8, 14, 17, 18, 42. 44, 63, 57. 59
Abrasive Disc Wheels (Including Segmental Discs) . 8, 25. 26, 42, 44, 63. 55. 59. 60
Type 4— Taper Sided Wheels 8, 17, 18. 44. 63, 59
Type 6— Recessed One Side Wheels . 9, 18, 64. 59
Type 6— Straight Cup Wheels 9, 16. 17, 18, 27, 42, 43, 44, 54, 59
Type 7— Double Recessed Wheels ,. 9, 18. 59
Type 11-f Flaring Cup Wheels . . • . 10^ 15. 17, 18, 27, 42, 43, 44. 54, 59
Type 12-i-Diah Wheels I 10. 17. 18, 69 .'
Typa 13-L-Saucer Wheels 10. 18, 69 I
Types 16, 17, 1SJ 18R and 19 Cone and Plug Wheels . 1 1. 24. 27. 54,'69
Types 20. 21, 22. 23. 24. 25. 26
Relieved and/or Recessed Wheels . 12, 18, 59
Types 27 and 28— Depressed Center Wheels 13. 30. 37, 39, 42, 43, 44. 53. 56, 59
Type 27A— Depressed Center Wheels .... 13. 42. 44. 63. 66. 69
Wheel Users See "LVir of Wheels a*d Machines-
Wire Winding 2. 4
Work Rests 21. 67, 68
292?
B0
o
American National Standards
The standard in this booklet is one of nearly 4,000 standards approved
to date by the American National Standards Institute, formerly the USA
Standards Institute.
The Standards Institute provides the machinery for creating voluntary
standards. It serves to eliminate duplication of standards activities and to
weld conflicting 1 standards into single, nationally accepted standards under
the designation "American National Standards."
Each standard represents general agreement among maker, seller, and
user groups as to the best current practice with- regard to some specific
problem. Thus the completed standards cut across the whole fabric of
production, distribution, and consumption of goods and services. Amer-
ican National Standards, by reason of Institute, procedures, reflect a na-
tional consensus of manufacturers, consumers,_and scientific, technical,
and professional organizations, and governmental agencies. The com-
pleted standards are used widely by industry and commerce and often by
municipal, state, and federal governments.
The Standards Institute, under whose auspices this work is being done,
is the United States clearing house and coordinating body for standards
activity on the national level. It is a federation of trade associations, tech-
nical societies, professional groups, and consumer organizations. Some
1,000 companies are affiliated with the Institute as company members.
The American National Standards Institute is the United States member
of the International Organization for Standardization (ISO), the Interna-
tional Electro-technical Commission (IEC), and:the Fan American Stand-
ards Commission (COPANT) . Through these channels American industry
makes its position felt on the international level. American National Stand-
ards are on file in the libraries of the nationaLatandards bodies of more
than 50 countries.
For a free list of all American National Standards, write:
American National Standards Institute
1430 Broadway New York, N.Y. 10018
2928 *" l
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