DEPARTMENT OF ENERGY, LABOR AND ECONOMIC GROWTH  
DIRECTOR'S OFFICE  
GENERAL INDUSTRY SAFETY STANDARDS  
(By authority conferred on the director of the department of energy, labor and economic  
growth by sections 16 and 21 of 1974 PA 154, and Executive Reorganization Order Nos.  
1996-2, 2003-1, and 2008-4, MCL 408.1016, 408.1021, 445.2001, 445.2011, and  
445.2025)  
PART 1A. ABRASIVE WHEELS  
GENERAL PROVISIONS  
R 408.10101 Scope.  
Rule 101. This part sets forth rules and specifications for the safe use of abrasive wheels  
in, around and about places of employment. They include specifications for safety guards,  
flanges, chucks and rules for storage, handling, mounting and use of all grinding wheels,  
except natural sandstone wheels.  
History: 1979 AC.  
R 408.10102 Definitions; A to C.  
Rule 102. (1) "Abrasive wheel-wheel" means a cutting tool that consists of abrasive grains  
held together by a bonding material.  
(2) "Blotter" means a flat disc of compressible material that is used to cushion the area of  
a grinding wheel coming in contact with a flange.  
(3) "Centerless O.D. grinding" means the precision grinding of the outer surface of any  
cylindrical workpiece which is rotated by a regulating wheel and supported by a work  
blade.  
(4) "Concrete sawing" means the cutting or slotting of materials such as concrete or  
asphalt where the sawing machine rides upon the surface being sawed.  
(5) "Contour grinding" means a grinding operation in which the grinding wheel or part  
follows a machine-generated contour.  
(6) "Cutting off" means the slicing or parting of any material or part.  
(7) "Cylindrical O.D. grinding" means the precision grinding of the outer surface of any  
cylindrical workpiece which is supported at one or both ends.  
History: 1979 AC; 1990 AACS.  
R 408.10103 Definitions; D to L.  
Page 1  
Rule 103. (1) "Disc or plate-mounted grinding" means the removal of material using an  
abrasive wheel fastened to a metal plate.  
(2) "Flange" means a collar, disc, or plate between which abrasive wheels are mounted.  
(3) "Form grinding" means to impart a specific shape or form onto a grinding wheel for  
the purpose of grinding that specific shape to the material or workpiece.  
(4) "Guard" means an enclosure that is designed to restrain pieces of abrasive wheel and  
protect the employee if the wheel breaks.  
(5) "Internal grinding" means the precision grinding of the inside surface of the hole in a  
workpiece.  
(6) "Lapidary" means to cut off, shape, or grind precious or semiprecious gem-like  
materials.  
History: 1979 AC; 1990 AACS.  
R 408.10104 Definitions; M to R.  
Rule 104. (1) "Masonry cutting" means the cutting off, notching or slotting of units of  
materials such as brick, tile, block or refractory shapes where the workpiece is brought to  
the machine.  
(2) "Mounted wheels" means various shaped abrasive wheels not more than 2 inches in  
diameter and mounted on a plain steel mandrel.  
(3) "Off-hand grinding" means the grinding of any material which is held in an employee's  
hand.  
(4) "Portable grinding" means a grinding operation where the machine is designed to be  
hand-held and may be easily moved from 1 location to another.  
(5) "Precision grinding" means the grinding operation performed by machines used to  
finish work parts to specified dimensions and finish requirements.  
(6) "Revolutions per minute--rpm" means the number of complete turns that a grinding  
wheel makes in 1 minute.  
History: 1979 AC.  
R 408.10105 Definitions; S to W.  
Rule 105. (1) "Shoulder grinding" means a periphery grinding operation where a limited  
amount of grinding with the side of the wheel may be performed.  
(2) "Snagging" means the grinding which removes relatively large amounts of material  
without regard to close tolerances or surface finish requirements.  
(3) "Surface feet per minute" or "sfpm" means the distance in feet that any 1 abrasive  
grain travels in l minute on a peripheral surface of a rotating grinding wheel.  
(4) "Surface grinding" means the precision grinding of a plane or formed surface.  
(5) "Tool or cutter grinding" means the precision grinding or sharpening of various types  
of cutting tools.  
(6) "Tuck pointing" means the removal, by grinding, of mortar, cement, or other  
nonmetallic material.  
(7) "Wheel types" means the classification of abrasive wheels as listed in the following  
order:  
Page 2  
SHAPE TYPES OF GRINDING WHEELS  
Type 1 – Straight wheel  
Peripheral grinding wheel having a diameter thickness and hole.  
Type 2 – Cylinder wheel.  
Side grinding wheel having a diameter, thickness and wall — wheel is mounted on the diameter, or a  
similar wheel mounted in a chuck or on a plate.  
Type 5 – Wheel, recessed one side.  
Peripheral grinding wheel having one side straight or flat and the opposite side recessed. A recessed  
wheel allows a wider faced grinding wheel to be used when the available  
mounting thickness (E) is less than the required overall thickness (T).  
The recess allows grinding clearance for the nut and flange.  
Page 3  
Type 6 – Straight-cup wheel.  
Side grinding wheel having a diameter, thickness and hole with one side straight or flat  
and the opposite side recessed. This type, however, differs from Type 5 in that the grinding is performed  
by the wall (W). The wall dimension (W) takes precedence over the diameter  
of the recess as an essential intermediate dimension to describe this shape type.  
NOTE: Arrows indicate grinding surface.  
Type 7 – Wheel, recessed two sides.  
Peripheral grinding wheel having both sides recessed to allow grinding clearance for both flanges or  
recessed so that an unusually wide faced wheel may be mounted when the available mounting thickness  
(E) is less than the overall thickness (T).  
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).  
Page 4  
Type 12 – Dish wheel.  
Side grinding wheel known as a dish, differing from a Type 11 in that Type 12  
always has a (U) dimension. The (W) dimension of a Type 11 becomes the (A) dimension  
of a Type 12. The grinding may be performed by the (U) face.  
Type 13 – Saucer wheel.  
Peripheral grinding wheel known as a saucer, differing from a Type 12 in that the  
cross-section is equal throughout (U=E). The face is always half-round with R=U/2.  
SHAPE TYPES OF GRINDING WHEELS CONES AND PLUGS  
On all cones and plugs grinding is performed by all surfaces except the flat (dimension “D”) on the mounting  
side. These shapes normally have a blind hole threaded bushing for mounting.  
Type 16 – Cone, curved side.  
Curved sided cone with a radius nose sometimes referred to as “Bullet shape.”  
Page 5  
Type 17 – Cone, straight side, square tip.  
Cone with a straight side, square tip.  
Type 18 – Plug, square end.  
Plug – Cylindrical in shape with a square end.  
Type 18R – Plug, round end.  
Plug – Cylindrical in shape with a radius nose. R=D/2  
Page 6  
Type 19 – Plugs, conical end, square tip.  
Combination cone and plug with a square tip similar to Type 17  
and the Cylindrical portion similar to Type 18.  
The cylindrical portion (S) is normally equal to or greater than  
the depth of the blind hole threaded bushing (B).  
NOTE: Arrows indicate grinding surface.  
RELIEVED AND/OR RECESSED WHEELS  
A relieved side is a depression in the side of the wheel which is tapered from a radial flat at the periphery (A)  
to an inside flat (K) or recess diameter (P).  
Type 20 – Wheel, relieved one side.  
Peripheral grinding wheel having one side straight or flat  
and the other side relieved to a flat.  
Type 21 – Wheel, relieved two sides.  
Peripheral grinding wheel having both sides relieved to a flat.  
Page 7  
Type 22 – Wheel, relieved one side, recessed other side.  
Peripheral grinding wheel having one side recessed and the other side relieved to a flat.  
Type 23 – Wheel, relieved and recessed same side.  
Peripheral grinding wheel having one side straight or flat  
and the other side relieved to a recess.  
Type 24 – Wheel, relieved and recessed one side, recessed other side.  
Peripheral grinding wheel having one side recessed  
and the other side relieved to a recess.  
Page 8  
Type 25 – Wheel, relieved and recessed one side, relieved other side.  
Peripheral grinding wheel having one side relieved to a flat  
and the other side relieved to a recess.  
Type 26 – Wheel, relieved and recessed both sides.  
Peripheral grinding wheel having both sides relieved to a recess.  
Type 27 – Wheel, depressed center.  
Portable Grinding: Grinding normally done by contact with work at approximately a 15° angle  
with face of wheel.  
Cutting-Off: When used as a cutting-off wheel, the periphery is the grinding face.  
Page 9  
Type 28 – Wheel, depressed center (saucer shaped grinding face).  
Portable Grinding: Grinding normally done by contact with work at approximately a 15° angle  
with face of wheel.  
NOTE: Arrows indicate grinding surface.  
History: 1979 AC; 1990 AACS.  
R 408.10111 Handling and storage of abrasive wheels.  
Rule 111. (1) An abrasive wheel shall not be dropped, bumped, or rolled.  
(2) An abrasive wheel shall be stored in a rack, bin, box, or drawer in a manner to prevent  
damage to the wheel.  
(3) An abrasive wheel shall be disbursed on a first-in first-out basis.  
(4) An abrasive wheel shall not be stored subject to:  
(a) Exposure to high humidity, water, or other liquids.  
(b) Freezing temperatures, or any temperature low enough to cause condensation on the  
wheel when moving it from storage to an area of higher temperature.  
History: 1979 AC.  
R 408.10113 Inspection of abrasive wheels.  
Rule 113. (1) At time of unpacking, an abrasive wheel shall be inspected for damage.  
(2) Prior to mounting, a vitrified or silicate wheel more than 4 inches in diameter shall be  
given a ring test by being tapped by a nonmetallic tool such as a handle of a screwdriver  
for a light wheel or a wooden mallet for a heavy wheel. The ring test shall be conducted as  
follows:  
(a) Wheels must be dry and free from sawdust when applying the ring test, otherwise the  
sound will be deadened.  
(b) 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 the figures below.  
(c) Then rotate the wheel 45 degrees and repeat the test.  
(d) A sound and undamaged wheel will give a clear metallic tone. If cracked, there will  
be a dead sound and not a clear "ring."  
Page 10  
Light Wheels  
Heavy Wheels  
Suspend from hole by small pin or finger  
Support on clean hard floor  
History: 1979 AC.  
R 408.10114 Work rests.  
Rule 114. (1) An off hand grinder shall be equipped with either a work rest so located that  
the point of grinding is on a horizontal plane with the wheel spindle, or a device which  
shall prevent the work piece from jamming between the abrasive wheel and the wheel  
guard. Where a work rest or device is used at a height other than the horizontal plane with  
the spindle, a warning sign shall be installed to prohibit use of the grinder for other than  
the job for which the work rest or device was set.  
(2) A work rest shall be adjusted and maintained to within 1/8 inch of the abrasive wheel.  
The adjustment shall be accomplished when the abrasive wheel is at rest.  
(3) A work rest shall be designed and constructed of metal capable of supporting the work  
piece.  
History: 1979 AC.  
R 408.10115 Machine spindles.  
Rule 115. (1) A wheel or flange that is secured by a spindle nut shall have the direction  
of the thread opposite that of the spindle rotation so that the nut will tighten as the spindle  
revolves.  
(2) A spindle shall be long enough to engage all the threads within the nut.  
(3) Spindle threads shall extend inside the flange, but not more than halfway within the  
hole of the abrasive wheel.  
(4) The spindle shall not be larger than the nominal size, with the undersize tolerance  
limited as required to prevent a hazardous condition.  
(5) A spindle on which a threaded-hole wheel is mounted shall be threaded to allow the  
abrasive wheel to be screwed flat against the back flange. In addition, all of the following  
requirements shall be complied with:  
Page 11  
(a) The direction of the thread shall be such that removing the abrasive wheel requires  
rotation of the wheel in the same direction that it turns when in use.  
(b) A spindle shaft shall not touch the bottom of a blind hole in an abrasive wheel.  
(c) A back flange that is specified in this rule shall be flat, unrelieved, and square to the  
spindle axis.  
History: 1979 AC; 1990 AACS.  
GUARDING PROVISIONS  
R 408.10121 General requirements.  
Rule 121. (1) An abrasive wheel shall be provided with a guard, except as noted in this  
subrule, which shall cover the spindle end, nut, and flange projections, as well as the  
periphery, other than where work is to be performed (see figures). Exceptions are as  
follows:  
(a) Wheels used for internal grinding while advancing or retracting the work or while  
within the work.  
(b) Mounted wheels that are not more than 2 inches in diameter.  
(c) Plug and cones that are not more than 3 inches in diameter or 5 inches in length.  
(d) A type l reinforced wheel which is not more than 3 inches in diameter and 1/4 inch  
thick and with which safety glasses and face shield protection are provided and used as  
prescribed in Part 33. Personal Protective Equipment, being R 408.13301 et seq. of the  
Michigan Administrative Code.  
(e) Lapidary grinding. A metal diamond lapidary blade which is notched, segmented, or  
continuous rim and which is used within a coolant deflector does not require guards for  
speeds of not more than 3,500 sfpm.  
(f) Tuck point wheel, masonry, or concrete saws may have the spindle end, nut, and flange  
exposed as per figures 1 and 2 of R 408.10198.  
(2) The guard shall be constructed of material that is capable of retaining pieces of a  
broken wheel. See material tables. The guard shall be mounted so as to maintain alignment  
with the abrasive wheel to contain wheel breakage, and the strength of the fastenings shall  
exceed the strength of the guard. The guard shall be in position before starting the wheel.  
(3) Where flying particles or fragments are a hazard to employees other than the grinder  
operator, an enclosure or barrier shall be provided to isolate the operation from the  
remaining working area.  
(4) When openings in the wheel safety guard assemblies are required for dressing, a means  
shall be provided to protect the operator and other personnel from the hazards of flying  
particles, sparks, or wheel fragments.  
History: 1979 AC; 1983 AACS; 1990 AACS.  
R 408.10122. Guard exposure angles.  
Rule 122. The maximum angle of exposure in a guard opening shall be as prescribed in  
table 1 of R 408.10199.  
Page 12  
History: 1979 AC; 2009 AACS.  
R 408.10123. Guard for portable grinders.  
Rule 123. A guard on a right angle head or vertical portable grinder shall have the guard  
located so as to be between the operator and the abrasive wheel during use (see figure 3 of  
R 408.10198 and table 2 of R 408.10199). A portable grinder using a depressed center  
wheel shall have a guard as prescribed in figure 4 of R 408.10198 and table 3 of R  
408.10199.  
History: 1979 AC; 2009 AACS.  
R 408.10124 Guarding cup wheels.  
Rule 124. (1) A cup wheel on a portable grinder shall be protected by a band-type guard.  
(2) A band-type guard shall be constructed as prescribed in figures 6 and 7 of R 408.10198  
and tables 4 and 5 of R 408.10199 and adjusted within 1/2 inch of the working surface of  
the abrasive wheel.  
(3) A revolving cup guard shall not be used as a method of safeguarding.  
(4) A guard for a tool and cutter grinder cup wheel shall be not less than 180 degrees of  
the periphery and the back side of the wheel shall be guarded. The spindle end and nut and  
front of the wheel need not be guarded if the spindle end and nut are inside the plane of the  
working face of the wheel. See figure 5 of R 408.10198.  
History: 1979 AC; 1990 AACS.  
R 408.10125 Exposure adjustments.  
Rule 125. A guard for an abrasive wheel on a bench, floor, or cylindrical grinder shall be  
constructed so that the peripheral protecting member can be adjusted to the decreasing  
diameter of the abrasive wheel. The distance between the abrasive wheel and the end of  
the peripheral member at the top shall not exceed 1/4 inch. An adjustable tongue may be  
used to achieve this dimension.  
History: 1979 AC.  
R 408.10126. Material requirements and minimum dimensions.  
Rule 126. (1) Figures 8 and 9 of R 408.10198 and table 6 of R 408.10199 shall be  
followed for material requirements, and minimum dimensions of peripheral and side  
members for guards. A cutting-off wheel 16 inches or less in diameter and operating at not  
more than 16,000 surface feet per minute may use cast or malleable iron as prescribed in  
table 6 of R 408.10199.  
(2) A cutting-off wheel larger than 16 inches and operating at not more than 14,200  
surface feet per minute shall have guards as prescribed in table 6 or 7 of R 408.10199.  
Page 13  
History: 1979 AC; 2009 AACS.  
R 408.10127. Construction of fabricated guards.  
Rule 127. (1) A fabricated guard made of structural steel shall be as prescribed in table 8  
of R 408.10199.  
(2) Column A of table 8 shall also apply to cast guards.  
(3) Column B of table 8 shall apply where an adjustable tongue is held by bolts.  
(4) Any means of fastening shall be considered satisfactory if, when assembled, it has  
strength at least equal to the members being joined.  
History: 1979 AC; 2009 AACS.  
R 408.10128. Construction of drawn steel guards.  
Rule 128. (1) A drawn steel guard for an abrasive wheel 8 inches and smaller on a  
portable grinder shall be as prescribed in figure 3 of R 408.10198 and table 2 of R  
408.10199.  
(2) A drawn steel guard for a depressed center wheel shall be as prescribed in figure 4 of  
R 408.10198 and table 3 of R 408.10199. The lip, shown as dimension B in figure 4 of R  
408.10198, shall curl inward to deflect pieces if an abrasive wheel breaks.  
History: 1979 AC; 2009 AACS.  
R 408.10129. Construction of band type guards.  
Rule 129. A band type guard for a segment, ring or nut inserted disc wheel shall be  
constructed as follows:  
(a) The band shall be steel plate or material of equal strength and as prescribed in figure  
10 of R 408.10198 and table 9 of R 408.10199. The band shall be continuous with the ends  
being welded, riveted or bolted in such a manner as to leave the inside free of projections.  
(b) The inside diameter of the band shall not be more than 1 inch larger than the outside  
diameter of the abrasive wheel and shall be concentric with the abrasive wheel.  
(c) The width and adjustment of the band shall be such that the wheel will not protrude  
beyond the edge of the band a distance greater than that prescribed in table 10 of R  
408.10199.  
History: 1979 AC; 2009 AACS.  
FLANGE PROVISIONS  
R 408.10141 General requirements.  
Rule 141. (1) An abrasive wheel shall be mounted between flanges, except as noted  
below, which shall not be less than 1/3 the diameter of the abrasive wheel. Exceptions:  
(a) Mounted wheel.  
Page 14  
(b) Portable cup, plug and cone wheels with threaded inserts or studs.  
(c) Abrasive disc of the inserted nut, inserted washer and projecting stud type.  
(d) Plate mounted wheel.  
(e) Cylinder, cup or segmented wheel mounted in a chuck.  
(f) Depressed center wheel.  
(g) Internal wheel less than 2 inches in diameter.  
(h) Straight and flaring cup wheel for terrazzo use.  
(i) Cutting-off wheel (see subrule (2)).  
(j) Masonry and concrete saws.  
(2) A straight cutting-off wheel shall be mounted between relieved flanges which are not  
less than 1/4 the wheel diameter. A depressed center cutting-off wheel more than 16 inches  
in diameter shall be mounted between flat unrelieved flanges not less than 1/4 the wheel  
diameter.  
(3) A masonry saw using a reinforced resinoid and steel-centered wheel may use 4-inch  
diameter flanges for wheels through 20-inch diameter.  
(4) Concrete saws using a steel-centered wheel 20-inch and larger may use flanges 1/6  
the wheel diameter.  
History: 1979 AC.  
R 408.10142. Flange construction.  
Rule 142. (1) Whenever a wheel is mounted between flanges, the flange shall be designed  
to transmit the driving torque from the spindle to the abrasive wheel. They shall be  
dimensionally accurate and balanced with no rough surfaces or sharp edges.  
(2) A flange shall be made of steel, cast iron or materials of equal strength and rigidity  
so that when tightened, the radial width of the bearing surface of contact on the abrasive  
wheel is maintained (see figure 11 of R 408.10198).  
(3) Two flanges between which an abrasive wheel is mounted, except when a special  
adaptor is used on a depressed center wheel, shall have the same dimensions and bearing  
surface.  
(4) The minimum dimensions for the following types of flanges shall be maintained  
according to the listed figures and tables:  
(a) Straight relieved flange - figure 11 of R 408.10198 and table 11 of R 408.10199.  
(b) Straight unrelieved flange - figure 12 of R 408.10198 and table 12 of R 408.10199.  
(c) Straight adaptor flange - figure 13 of R 408.10198 and table 13 of R 408.10199.  
(d) Straight flange - figures 14 and 15 of R 408.10198 and table 14 of R 408.10199.  
(e) Straight adaptor flange - figure 16 of R 408.10198 and table 15 of R 408.10199.  
(f) Straight adaptor flange - heavy duty - figures 17 and 18 of R 408.10198 and table 16  
of R 408.10199.  
(g) Arborless wheel flange - figures 19 and 20 of R 408.10198 and table 17 of R  
408.10199.  
(h) Straight flange for wheel sleeves - figure 21 of R 408.10198 and table 18 of R  
408.10199.  
History: 1979 AC; 2009 AACS.  
Page 15  
R 408.10143. Maintenance for flanges.  
Rule 143. (1) A flange with a worn, warped, sprung or damaged bearing surface shall be  
repaired or replaced.  
(2) When resurfacing a straight relieved flange, a recess of not less than 1/16 inch shall  
be maintained on the side next to the wheel for a distance prescribed in table 11 of R  
408.10199.  
(3) When resurfacing a straight flange of the adaptor or sleeve type, the undercut shown  
in figures 14 and 15 of R 408.10198 shall be maintained to insure that there will be no  
bearing on the sides of the abrasive wheel within 1/8 inch of the arbor hole.  
History: 1979 AC; 2009 AACS.  
MOUNTING PROVISIONS  
R 408.10151 Bushings.  
Rule 151. A bushing used in mounting an abrasive wheel shall not be greater than the  
width of the wheel or make contact with the flange.  
History: 1979 AC.  
R 408.10152 Blotters.  
Rule 152. A blotter shall be used between a flange and the abrasive wheel. The blotter  
shall cover the entire contact area of the flange. Exceptions:  
(a) Mounted, cone, and plug wheels.  
(b) Abrasive discs--inserted nut, inserted washer, and projecting stud type.  
(c) Plate mounted wheels.  
(d) Cylinders, cups, or segmented wheels that are chuck mounted.  
(e) Type 27 and 28 depressed center wheels.  
(f) Cutting-off wheels.  
(g) Internal wheels not more than 2 inches in diameter.  
(h) Type 4 tapered wheels.  
(i) Diamond and Borzon type wheels.  
(j) Terrazzo wheels.  
(k) Type 27A cutting-off wheels.  
History: 1979 AC.  
R 408.10153 Multiple wheel mounting.  
Rule 153. When mounting more than 1 abrasive wheel between a pair of flanges, the  
wheels shall be cemented together, separated by spacers having low compressibility such  
as soft copper or brass or especially manufactured for mounting without cementing or use  
Page 16  
of the prescribed spacers. The spacers shall be equal in diameter to the flanges and have  
equal bearing surfaces.  
History: 1979 AC.  
R 408.10154 Mounting nuts.  
Rule 154. (1) A single spindle nut shall be tightened only enough to drive the abrasive  
wheel and prevent slippage.  
(2) A multiple screw flange shall be tightened uniformly to distribute pressure over the  
flange surface and prevent springing of the flange.  
History: 1979 AC.  
R 408.10155. Mounting of abrasive disc wheels.  
Rule 155. (1) An inserted nut wheel shall be mounted with a steel machine face plate of  
the same diameter as the wheel. The thickness of the machine face plate shall be as  
prescribed in table 19 of R 408.10199.  
(2) A screw hole in the machine face plate shall be located to match the threaded hole in  
the inserted nut and large enough so the screw will not bind. Each screw hole in the plate  
shall be countersunk to a uniform depth to accommodate the screw head. A screw shall  
engage the threads of the inserted nuts, but not touch the bottom of the hole.  
(3) A machine face plate shall be flat, concentric and mounted at a 90 degree angle to the  
machine spindle.  
(4) A plate mounted wheel having a mounting plate thinner than prescribed in table 19  
shall have an additional machine face plate installed to provide the additional strength  
needed. The added machine face plate shall have the same diameter as the wheel (see figure  
22 of R 408.10198 and table 20 of R 408.10199).  
History: 1979 AC; 2009 AACS.  
R 408.10156 Mounting depressed center wheels.  
Rule 156. (1) A depressed center wheel, except as prescribed in rule 157, shall be mounted  
with specially designed adaptors.  
(2) 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.  
(3) The adaptor nut which is less than the minimum 1/3 diameter of the wheel shall fit  
into the depressed side to prevent interference in side grinding and drive the wheel by its  
clamping force against the depressed portion of the back flange.  
(4) Adaptors affixed by the depressed center wheel manufacturer shall not be reused.  
History: 1979 AC.  
R 408.10157 Mounting depressed center cutting-off wheels.  
Page 17  
Rule 157. A depressed center cutting-off wheel more than 16 inches in diameter shall be  
mounted with flat unrelieved flanges having matching bearing surfaces not less than 1/4  
the wheel diameter.  
History: 1979 AC.  
R 408.10158 Mounting cylinder wheels.  
Rule 158. (1) A cylinder wheel shall be cemented or chucked onto a machine face plate  
which shall be flat, concentric, and mounted at 90 degrees to the machine spindle.  
(2) A cylinder wheel shall be used only on a machine equipped with a band-type guard as  
prescribed in R 408.10129.  
History: 1979 AC.  
R 408.10159 Mounting segments.  
Rule 159. (1) Segments shall be chucked in a holding mechanism as prescribed by the  
manufacturer of the chucking device.  
(2) The segments shall be used only on a machine equipped with a band-type guard as  
prescribed in R 408.10129.  
History: 1979 AC.  
SPEED PROVISIONS  
R 408.10171 Rescinded.  
History: 1979 AC; 1990 AACS.  
R 408.10172 Rescinded.  
History: 1979 AC; 1990 AACS.  
R 408.10173 Training, maintenance, and procedures to prevent wheel overspeed.  
Rule 173. An employer shall establish appropriate training, maintenance, and procedures  
to assure that wheel overspeed will not occur on an abrasive wheel.  
History: 1990 AACS.  
R 408.10174 Grinding machine spindle speeds.  
Rule 174. (1) The spindle speed shall be permanently marked on a grinding machine and  
maintained in a legible manner.  
Page 18  
(2) The spindle speed shall not exceed the rated speed of the grinding wheel.  
(3) The wheel spindle speed on a single-speed grinding machine shall be checked with a  
tachometer when a change is made which could affect the spindle speed.  
(4) The wheel spindle speed on an air-driven grinder shall be checked with a tachometer  
as follows:  
(a) After maintenance or repair.  
(b) When in use, with such checks being performed as often as necessary to assure that  
wheel overspeed will not occur.  
(5) The wheel spindle speed of a vari-speed grinding machine shall be checked with a  
tachometer as follows:  
(a) When in use, with such checks being performed as often as necessary to assure that  
wheel overspeed shall not occur.  
(b) After any change that could affect the spindle speed.  
(c) When a new wheel is mounted.  
History: 1990 AACS.  
R 408.10175 Wheel speeds.  
Rule 175. (1) An abrasive wheel or its package shall show the maximum operating speed  
as revolutions per minute. The use of a package for this marking shall be limited to those  
shapes which make marking unfeasible.  
(2) Except as provided for in R 408.10177, an abrasive wheel shall be run at a speed which  
is not more than that prescribed in table 21 of R 408.10199, but not more than the rated  
speed on the wheel. The revolutions per minute may be increased as the wheel diameter  
decreases if the original surface feet per minute speed is not exceeded. Wheel speed shall  
be computed from the free-running speed of the machine spindle.  
(3) An employer shall purchase and use only an abrasive wheel which has been speed  
tested, as prescribed in table 22 of R 408.10199, by the manufacturer, with the following  
exceptions:  
(a) A wheel that is less than 6 inches in diameter.  
(b) A diamond or cubic boron nitride wheel that is bonded by metal or organic substances.  
(c) A segmental disc wheel and disc wheel.  
(d) A ball grinding wheel.  
(e) A regulating wheel for centerless grinders.  
(f) A mounted wheel.  
(g) A segment.  
(4) The operating speed and overhang of a mounted wheel shall be not more than that  
prescribed in tables 23 to 31 of R 408.10199 (See figure 23).  
History: 1990 AACS.  
SPECIAL SPEEDS  
R 408.10177 Special speeds.  
Page 19  
Rule 177. (1) Wheels that are used on special applications at speeds higher than those  
listed in table 21 of R 408.10199 shall be marked for high-speed application and the  
specific conditions of use. The marked maximum speed of the wheel shall not be exceeded.  
(2) The machine and its components, such as the spindle, bearings, guards, flanges, and  
rated horsepower, shall be such that the entire unit will operate safely at the special speed.  
(3) An employer shall assure that a machine is operated with safety guards as prescribed  
in this part and that a machine and guards are maintained in good condition for continued  
safety.  
History: 1990 AACS.  
OPERATING PROVISIONS  
R 408.10181 Operating provisions.  
Rule 181. (1) A grinding machine with a vari-speed control shall have the speed  
adjustment supervised by an authorized and trained employee.  
(2) Before mounting a wheel on a vari-speed grinder, an employee shall adjust the speed  
of a machine to not more than the rated speed of the wheel.  
History: 1979 AC; 1990 AACS.  
R 408.10182 Training.  
Rule 182. An employee shall be instructed in the care, use, and protection of an abrasive  
wheel and equipment before assignment.  
History: 1979 AC.  
R 408.10183 Wheel breakage.  
Rule 183. (1) A cracked or broken wheel shall not be used.  
(2) Wheel breakage shall be investigated by the employer to determine and correct the  
cause.  
History: 1979 AC.  
R 408.10184 Starting new wheels.  
Rule 184. After mounting an abrasive wheel, it shall be run with the guard in place or in  
an enclosure at operating speed for not less than 1 minute before applying work. During  
this time an employee shall not stand in front of or in line with the wheel.  
History: 1979 AC.  
Page 20  
R 408.10185 Truing and dressing wheels.  
Rule 185. An out-of-truth abrasive wheel shall be trued by a trained employee. A wheel  
which cannot be trued shall not be used.  
History: 1979 AC.  
R 408.10186 Side, form, shoulder, and contour grinding.  
Rule 186. Side grinding shall only be performed on an abrasive wheel that is designed for  
that purpose. A wheel designed for grinding on the periphery shall not be used for side  
grinding. This does not preclude wheel use for applications such as shoulder, form, and  
contour grinding, where it is recognized that a limited amount of grinding with the side of  
the wheel is performed with a wheel that is designed for periphery grinding.  
History: 1979 AC; 1990 AACS.  
R 408.10187 Maintenance.  
Rule 187. (1) An employer shall maintain grinding equipment in a condition which will  
not create a hazard for the employee.  
(2) An employer shall instruct the employee to report defective equipment to the  
employee's supervisor.  
History: 1979 AC; 1990 AACS.  
R 408.10198 Figures.  
Rule 198. Figures 1 to 23 read as follows:  
FIGURES 1 TO 23  
FIGURE 1  
FIGURE 2  
Page 21  
FIGURE 3  
TYPICAL DRAWN STEEL GUARD FOR WHEELS  
8 inches Diameter and Smaller a, b & c  
FIGURE 4  
DRAWN STEEL GUARD FOR PORTABLE GRINDERS  
USED WITH DEPRESSED CENTER WHEELS  
Page 22  
FIGURE 5  
FIGURE 6  
TYPICAL FABRICATED STEEL BAND-TYPE GUARD  
FOR SQUARED OR TAPERED CUP WHEELS  
Page 23  
FIGURE 7  
TYPICAL DRAWN STEEL BAND-TYPE GUARD FOR TAPERED CUP WHEELS  
Page 24  
FIGURE 8  
FIGURE 9  
MINIMUM BASIC THICKNESS OF PERPHERAL  
AND SIDE MEMBERS FOR SAFETY GUARDS  
FIGURE 10  
BAND-TYPE GUARD FOR RING, SEGMENT, NUT INSERTED WHEELS  
FIGURE 11  
FIGURE 12  
Page 25  
FIGURE 13  
FIGURE 14  
CENTRAL NUT MOUNTING  
FIGURE 15  
MULTIPLE SCREW MOUNTING  
FIGURE 16  
FIGURE 17  
MULTIPLE SCREW MOUNTING  
Page 26  
FIGURE 18  
CENTRAL NUT MOUNTING  
FIGURE 19  
DOUBLE END SPINDLE  
FIGURE 20  
OPEN END SPINDLE  
Page 27  
FIGURE 21  
FIGURE 22  
Pd shall never be less than  
nor shall the difference  
between D and Pd exceed 2 inches. It is recommended that  
Pd equal D wherever practical.  
FIGURE 23  
DEFINING OVERHAND DIMENSIONS IN TABLES 23 TO 31  
History: 1990 AACS.  
Page 28  
R 408.10199 Tables.  
Rule 199. Tables 1 to 31 read as follows:  
TABLES 1 TO 31  
TABLE 1  
GUARD EXPOSURE ANGLE  
Exposure Above or Below  
Horizontal Plane  
Grinder Type  
Total Exposure  
Bench and Floor  
Cylindrical Grinder  
Surface Grinder  
Cut-off Machine  
Swing Frame  
65 degrees above  
65 degrees above  
15 degrees below  
15 degrees below  
*90 degrees  
180 degrees  
150 degrees  
150 degrees  
180 degrees  
180 degrees  
60 degrees  
Snagging  
Top  
30 degrees above  
35 degrees above  
Portable  
180 degrees  
180 degrees  
180 degrees  
Masonry and Concrete Saws  
Tool and Cutter Grinder  
*Whenever the nature of the work requires contact with the abrasive wheel below the horizontal plane of  
the spindle, the exposure shall not exceed 125 degrees.  
TABLE 2  
GUIDE FOR CONSTRUCTION OF DRAWN STEEL GUARDS FOR WHEEL  
2” THICK AND LESS, 8” AND LESS IN DIAMETER  
*Material Used in  
2 to 5 inches  
Above 5 to 8 inches  
Construction of Guard  
Hot Rolled Steel SAE  
1008 Min. Tensile  
Strength 60,000 PSI for  
speeds up to (SFPM)  
Maximum  
Thickness of  
Wheel,  
A
B
A
B
Inches  
Inches  
Inches  
Inches  
Inches  
9,500  
12,500  
17,000  
2
2
1
1/16  
3/32  
3/32  
1/16  
1/16  
1/16  
3/32  
3/32  
1/8  
1/16  
3/32  
3/32  
*The recommendations listed in the above table are guides for the conditions stated. Other material,  
designs or dimensions affording equal or superior protection are also acceptable.  
Page 29  
TABLE 3  
DRAWN STEEL GUARD FOR PORTABLE GRINDERS  
USED WITH DEPRESSED CENTER WHEELS  
Wheel  
Diameter  
Inches  
Material Used in Construction  
of Guard  
Thickness of  
Wheel  
A
Inches  
B
Inches  
*Hot Rolled  
Steel SAE  
1008 min.  
tensile strength  
60,000 PSI  
3/8 inches or  
less  
2 to 9  
7 to 9  
1/16  
3/32  
1/2  
For speeds up  
to 14,200  
SFPM  
Over 3/8 to 1  
inch  
1 1/8  
*The recommendations listed in the above table are guides for the conditions stated. Other material,  
designs or dimensions affording equal or superior protection are also acceptable.  
TABLE 4  
TABLE FOR FABRICATED STEEL GUARDS FOR SQUARED OR TAPERED CUP WHEELS  
Bolts Connecting  
Wheel Diameter*  
Back Thickness  
*Band Thickness  
Band to Back  
Member  
4”  
5”  
6”  
.056 – .064  
.082 – .098  
.082 – .098  
.112 – .128  
.112 – .128  
.112 – .128  
3 5/16 – 18  
3 5/16 – 18  
3 3/8 – 16  
TABLE 5  
TABLE FOR DRAWN STEEL GUARDS FOR TAPERED CUP WHEELS  
Bolts  
Connecting  
Hood to Band Thickness  
Washer  
Back Plate  
Wheel  
Diameter  
Bolts to  
Machine  
“B”  
O.D.  
*“C”  
Hood  
*”D”  
Band  
“A”  
No.  
No.  
4”  
5”  
6”  
1 7/8  
2 1/8  
2 5/8  
4
4
4
1/4 – 20  
5/16 – 18  
5/16 – 18  
3
3
4
5/16 – 18 x 3/4 .097 – .112  
4
.056 – .064 .112 – .128  
5/16 – 18 x 3/4 .097 – .112 4 3/4 .082 – .098 .112 – .128  
5/16 – 18 x 3/4 .097 – .112 4 3/4 .082 – .098 .112 – .128  
*The recommendations listed in the above tables are guides for the conditions stated.  
Other material, designs or dimensions affording equal or superior protection are also acceptable.  
Page 30  
TABLE 6  
MINIMUM BASIC THICKNESSES OF PERIPHERAL AND SIDE MEMBERS FOR SAFETY GUARDS  
GRINDING WHEEL DIAMETERS  
Maximum  
Thickness  
of Grinding  
Wheel  
Material Used  
in Construction  
of Guard  
Over 6 to 12  
inches  
Over 12 to 16  
Over 16 to 20  
inches  
Over 20 to 24  
Over 24 to 30  
inches  
Over 30 to 48  
inches  
3 to 6 inches  
inches  
inches  
A
B
A
B
A
B
A
B
A
B
A
B
A
B
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
2
4
1/4  
1/4  
3/8  
3/8  
1/2  
5/8  
3/4  
5/16  
5/16  
7/16  
9/16  
11/16  
1/2  
1/2  
3/8  
3/8  
1/2  
3/4  
3/4  
1
5/8  
3/4  
1
1/2  
5/8  
7/8  
1
5/8  
5/8  
1
3/4  
3/4  
1 1/4  
1 3/8  
1 1/2  
1 1/2  
1 1/2  
1 3/4  
2
1
1
5/16  
3/8  
5/16  
5/16  
1 1/8  
1 1/4  
1 1/4  
1 1/4  
1 7/16  
1 1/2  
7/8  
6
5/8  
5/8  
1 1/8  
1 1/8  
1 1/8  
1 5/16  
1 3/8  
3/4  
3/4  
7/8  
1 1/8  
1 1/8  
1 1/8  
1 3/8  
1 5/8  
7/8  
8
7/8  
1
3/4  
3/4  
7/8  
10  
16  
20  
2
7/8  
1
3/4  
3/4  
7/8  
1 1/8  
1 1/4  
1 3/8  
5/8  
5/8  
3/4  
3/4  
3/4  
1
1
1 1/16  
1 3/8  
3/4  
1 1/8  
1/2  
1 1/8  
5/8  
1/4  
5/16  
3/8  
1/4  
3/8  
3/8  
1/2  
1/2  
1/2  
5/16  
5/16  
7/16  
7/16  
7/16  
1/2  
1/2  
5/8  
5/8  
5/8  
3/8  
3/8  
1/2  
1/2  
1/2  
1
4
5/16  
5/16  
1/2  
3/4  
5/8  
7/8  
3/4  
1 1/8  
1 1/4  
1 1/4  
1 1/4  
1 3/8  
1 1/2  
7/8  
7/8  
6
5/8  
7/8  
5/8  
1
3/4  
7/8  
8
5/8  
7/8  
5/8  
1
3/4  
7/8  
10  
5/8  
7/8  
5/8  
1
3/4  
7/8  
16  
20  
2
13/16 11/16 13/16  
7/8  
11/16  
3/4  
1
3/4  
1 1/8  
1 1/8  
3/4  
7/8  
1
1
3/4  
7/8  
1 1/8  
3/4  
1/4  
1/4  
3/8  
1/4  
1/4  
1/4  
5/16  
1/2  
3/4  
7/8  
1
5/16  
1/2  
5/8  
3/4  
7/8  
3/8  
1/2  
3/4  
7/8  
1
3/8  
1/2  
1/2  
9/16  
3/4  
7/16  
1/2  
5/8  
1/2  
5/8  
4
5/8  
1/2  
3/4  
5/8  
1
3/4  
6
5/8  
5/8  
13/16  
7/8  
11/16  
3/4  
13/16  
15/16  
1 1/8  
1 1/4  
1 7/16  
3/8  
11/16  
13/16  
1
1 1/8  
1 3/8  
1 7/16  
1 13/16  
2 1/16  
1/2  
3/4  
8
3/4  
7/8  
3/4  
1
10  
16  
20  
2
7/8  
1
7/8  
1 1/8  
1 1/4  
1 3/8  
5/16  
3/8  
15/16  
1 1/8  
1 1/4  
1/4  
1 1/16  
1 7/16  
1 11/16  
3/8  
1 1/4  
1 1/8  
1 1/4  
1 3/8  
5/16  
3/8  
1 1/8  
1 1/4  
1/4  
1 1/8  
1 5/16  
5/16  
5/16  
3/8  
1/8  
1/8  
1/16  
1/16  
1/16  
5/16  
3/8  
1/4  
5/16  
3/8  
5/16  
3/8  
1/4  
5/16  
3/8  
4
5/16  
3/8  
5/16  
3/8  
3/8  
1/2  
3/8  
6
3/16  
1/2  
7/16  
9/16  
5/8  
7/16  
9/16  
5/8  
7/16  
9/16  
5/8  
7/16  
5/8  
3/4  
1/2  
8
1/2  
3/8  
7/16  
1/2  
7/16  
1/2  
7/16  
1/2  
1/2  
3/4  
1/2  
10  
16  
20  
9/16  
7/16  
5/8  
1/2  
7/8  
5/8  
5/8  
9/16  
3/4  
5/8  
3/4  
5/8  
13/16  
7/8  
11/16  
3/4  
1 1/16  
1 3/16  
13/16  
15/16  
13/16  
11/16  
13/16  
11/16  
*The recommendations listed in the above table are guides for the conditions stated.  
Other material, designs or dimensions affording equal or superior protections are also acceptable.  
Page 31  
TABLE 7  
MINIMUM BASIC THICKNESS FOR PERIPHERAL AND SIDE  
MEMBERS FOR SAFETY GUARDS USED WITH CUTTING-OFF WHEELS  
Cutting Off Wheel Diameters  
Material Used Maximum  
Speed  
Not to  
Exceed  
Over 20  
to 30  
inches  
Over 48  
to 72  
inches  
in  
Thickness  
of Cutting  
Off Wheel  
6 to 11  
inches  
Over 11 to  
20 inches  
Over 30 to  
48 inches  
Construction  
of Guard  
A
B
A
B
A
B
A
B
A
B
*Structural  
Steel  
(Min. Tensile  
Strength  
1/2 inch or  
less  
14,200  
SFPM  
1/16 1/16 3/32 3/32 1/8 1/8 3/16 3/16 1/4 1/4  
3/32 1/8 1/8 1/8 3/16 1/8 1/4 3/16 5/16 1/4  
1/2 inch or  
less  
16,000  
SFPM  
60,000 PSI)  
*The recommendations listed in the above table are guides for the conditions stated.  
Other material, designs or dimensions affording equal or superior protection are also acceptable.  
TABLE 8  
DIMENSIONAL REQUIREMENTS FOR CONSTRUCTION OF FABRICATED GUARDS  
MAXIMUM WHEEL SPEED 10,000 SFPM  
A
B
C
D
E
F
G
H
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
Inches  
1 1/2  
wider than  
wheel  
1 1/2 x 1 1/2  
x 5/16  
4 ea. @  
1/2  
Under 12  
3 1/2  
9/16  
1/2  
1/4  
1 1/2  
4 ea. @  
5/8  
2 wider  
than wheel  
16  
24  
30  
5
6
7
5/8  
3/4  
2 x 2 x 5/16  
2 x 2 x 1/2  
9/16  
5/8  
5/16  
1/2  
1 1/2  
1 1/2  
1 1/2  
6 ea. @  
5/8  
2 wider  
than wheel  
2 1/2 x 2 1/2  
x 1/2  
6 ea. @  
11/16  
2 wider  
than wheel  
11/16  
11/16  
1/2  
NOTE: Column D assumes low carbon steel (38,000 PSI tensile) rivets. Two rivets per bar 12 and 16” diameter. For rivets  
per bar 24 and 30” diameter.  
Page 32  
TABLE 9  
GUIDE FOR CONSTRUCTION OF BAND TYPE GUARDS  
Maximum Wheel Speed 7000 SFPM For Ring, Segment, Nut Inserted Wheels  
Maximum  
Material  
Specifications  
Minimum  
Thickness of  
Band A  
Minimum  
Diameter of  
Rivets  
Maximum  
Distance Between  
Centers of Rivets  
Diameter of  
Wheel  
Inches  
Under 8  
Inches  
1/16  
1/8  
Inches  
3/16  
1/4  
Inches  
3/4  
*Hot Rolled Steel  
SAE 1008  
8 to 24  
1
Over 24 to 30  
1/4  
3/8  
1 1/4  
* The recommendations listed in the above table are guides for the conditions stated. Other material,  
designs or dimensions affording equal or superior protection are also acceptable.  
TABLE 10  
GUIDE FOR CONSTRUCTION OF BAND TYPE GUARDS  
EXPOSURE VERSUS WHEEL THICKNESS  
Overall Thickness of Wheel (T) Inches  
Maximum Exposure of Wheel (C) Inches  
1/2  
1/4  
1/2  
3/4  
1
1
2
3
4
1 1/2  
2
5 and over  
Page 33  
TABLE 11  
MINIMUM DIMENSIONS FOR STRAIGHT RELIEVED FLANGES  
A*  
B
C
D
E
Minimum  
Thickness of  
Flange at  
Edge of  
Radial Width of Bearing  
Surface  
**Minimum  
Outside  
Diameter of  
Flanges  
Minimum  
Thickness of  
Flange at  
Bore  
Diameter of  
Wheel  
Minimum  
Maximum  
Recess  
Inches  
1
Inches  
3/8  
3/4  
1
Inches  
1/16  
1/8  
Inches  
1/8  
Inches  
1/16  
1/8  
Inches  
1/16  
3/32  
3/32  
1/8  
2
3/16  
3/16  
3/16  
1/4  
3
1/8  
3/16  
3/16  
1/4  
4
1 3/8  
1 3/4  
2
1/8  
5
3/16  
1/4  
1/8  
6
1/2  
3/8  
3/16  
3/16  
3/16  
1/4  
7
2 1/2  
3
1/4  
1/2  
3/8  
8
1/4  
1/2  
3/8  
10  
12  
14  
16  
18  
20  
22  
24  
26  
28  
30  
36  
42  
48  
60  
72  
3 1/2  
4
5/16  
5/16  
3/8  
5/8  
3/8  
5/8  
1/2  
5/16  
5/16  
5/16  
3/8  
4 1/2  
5 1/2  
6
3/4  
1/2  
1/2  
1
1/2  
1/2  
1
5/8  
7
5/8  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/2  
1 1/2  
2
5/8  
3/8  
7 1/2  
8
5/8  
5/8  
7/16  
7/16  
1/2  
3/4  
5/8  
8 1/2  
10  
3/4  
5/8  
7/8  
3/4  
1/2  
10  
7/8  
3/4  
5/8  
12  
1
7/8  
3/4  
14  
1
2
7/8  
3/4  
16  
1 1/4  
1 1/4  
1 1/2  
2
1 1/8  
1 1/4  
1 3/8  
1
20  
2
1 1/8  
1 1/4  
24  
2 1/2  
* Flanges for wheels under 2 inches diameter may be unrelieved and shall be maintained flat and true.  
** See rule 141.  
Page 34  
TABLE 12  
MINIMUM DIMENSIONS FOR STRAIGHT UNRELIEVED FLANGES  
FOR WHEELS WITH THREADED INSERTS OR PROJECTING STUDS  
A
B*  
T
Minimum Outside  
Diameter of Flange  
Minimum Thickness  
of Flange  
Diameter of Wheel  
Inches  
Inches  
5/8  
1
Inches  
1/8  
1
2
3
4
5
6
1/8  
1
3/16  
3/16  
1/4  
1 3/8  
1 3/4  
2
3/8  
* NOTE:  
Must be large enough to extend beyond the bushing. Where prong anchor or cupback  
bushing are used, this footnote does not apply.  
TABLE 13  
MINIMUM DIMENSIONS FOR STRAIGHT ADAPTOR FLANGE  
FOR ORGANIC BONDED WHEELS OVER 1 1/4 INCH THICK  
B
D
E
F*  
Minimum  
Thickness  
of Flange  
at Edge of  
Undercut  
Minimum  
Thickness  
of Flange  
at Bore  
Minimum  
Flange  
Diameter  
(D-E)  
Minimum  
Thickness  
Wheel  
Diameter  
Wheel Hole  
Diameter  
Inches  
Inches  
Inches  
Inches  
7/8  
7/8  
7/8  
7/8  
7/8  
7/8  
7/8  
7/8  
1
Inches  
3/8  
3/8  
3/8  
3/8  
3/8  
3/8  
3/8  
3/8  
1/2  
1/2  
1/2  
1/2  
1/2  
Inches  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
4
5
6
7
12 to 14  
6
8
4
6
5
7
Larger than  
14 to 18  
6
8
7
9
8
10  
8
6
7
9
1
Larger than  
18 to 24  
8
10  
12  
14  
1
10  
12  
1
1
Larger than 24  
to 30  
12  
12  
15  
15  
1
1/2  
7/8  
1/2  
1/2  
Larger than 30  
to 36  
1 3/8  
* For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of wheel thickness.  
Page 35  
TABLE 14  
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES  
FOR AUTOMATIC SNAG MACHINES 12,500 S.F.P.M. TO 16,500 S.F.P.M.1  
B
D
E
F*  
Minimum  
Thickness of  
Flange at  
Bore  
Minimum  
Thickness of  
Flange at Edge  
of Undercut  
Minimum  
Flange  
Diameter  
(D-E)  
Minimum  
Thickness  
Wheel  
Diameter  
Wheel Hole  
Diameter  
20  
20  
24  
30  
36  
6
8
1
1/2  
3/4  
3/4  
3/4  
3/4  
1/2  
3/4  
3/4  
3/4  
3/4  
8
10  
15  
15  
15  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
12  
12  
12  
1 FLANGES shall be of steel, quality SAE 1040 or equivalent, annealed plate, heat treated to R c 25-  
30.  
* For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of wheel thickness.  
TABLE 15  
MINIMUM DIMENSIONS FOR STRAIGHT ADAPTOR FLANGE  
FOR ORGANIC BONDED WHEELS USED ON SWING FRAME GRINDERS  
AT 12,500 S.F.P.M. TO 16,500 S.F.P.M.1  
B
D
E
F*  
Minimum  
Thickness of  
Flange at  
Bore  
Minimum  
Thickness of  
Flange at Edge  
of Undercut  
Minimum  
Flange  
Diameter  
(D-E)  
Minimum  
Thickness  
Wheel  
Diameter  
Wheel Hole  
Diameter  
20  
20  
24  
30  
6
8
8
1
1
1
1
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
10  
15  
15  
12  
12  
1 FLANGES shall be of steel, quality SAE 1040 or equivalent, annealed plate, heat treated to R c 25-  
30.  
* For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of wheel thickness.  
Page 36  
TABLE 16  
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES FOR HEAVY DUTY,  
HIGH SPEED FLOOR STAND GRINDERS1  
12,500 S.F.P.M. TO 16,5000 S.F.P.M.  
B
D
Minimum Flange  
Diameter  
Minimum Thickness  
of Flange at Bore  
Wheel Diameter  
Hole Diameter  
20  
24  
30  
6 thru 10  
8 thru 12  
1
1
1
12  
15  
12  
15  
1 FLANGES shall be of steel, quality SAE 1040 or equivalent, annealed plate, heat treated to R c 25-  
30.  
TABLE 17  
MINIMUM DIMENSIONS FOR FLANGES  
FOR ARBORLESS WHEELS – ORGANIC BOND  
“B” Minimum  
Flange  
Torque Used in  
Mounting  
Minimum Hole Size  
Dimensions. (8 holes)  
(holes equally spaced)  
Wheel  
Diameter  
Bolt Circle  
Diameter  
Ft. Lbs.  
All mounting holes shall be  
17/32” inside diameter, with  
a fiber bushing in place, not  
to exceed 21/32” outside  
diameter.  
16  
20  
24  
30  
6 1/2  
8
8 7/8  
10 3/8  
12  
30-40  
30-40  
40-60  
40-60  
9 5/8  
12  
14 3/8  
Page 37  
TABLE 18  
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES  
USED AS WHEEL SLEEVES FOR PRECISION GRINDING ONLY  
B
D
E
Minimum  
Outside  
Diameter of  
Flange  
Minimum  
Thickness of  
Flange at Edge of  
Undercut  
Minimum  
Thickness of  
Flange at Bore  
Wheel Hole  
Diameter  
Wheel Diameter  
Inches  
Inches  
5
Inches  
7
Inches  
1/2  
5/8  
5/8  
5/8  
5/8  
5/8  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
1
Inches  
7/16  
7/16  
7/16  
7/16  
7/16  
7/16  
1/2  
12 to 14  
5
7
6
8
Larger than  
14 to 20  
8
10  
10  
12  
8
11 1/2  
13 1/2  
10  
10  
12  
16  
12  
16  
18  
20  
16  
20  
24  
11 1/2  
13 1/2  
17 1/2  
13 1/2  
17 1/2  
19 1/2  
21 1/2  
20  
1/2  
Larger than  
20 to 30  
1/2  
1/2  
1/2  
1/2  
Larger than  
30 to 42  
1/2  
1/2  
3/4  
Larger than  
42 to 60  
24  
1
3/4  
29  
1 1/8  
7/8  
Note: These flanges may be clamped together by means of a central nut,  
or by a series of bolts or some other equivalent means of fastening.  
For hole sizes smaller than shown in this table, use table 9.  
TABLE 19  
MINIMUM THICKNESS OF STEEL DISC WHEELS  
(MACHINE FACE PLATE) FOR MOUNTING ABRASIVE DISCS  
Diameter Inches  
8 to 14 inclusive  
15 to 18 inclusive  
19 to 26 inclusive  
27 to 36 inclusive  
37 to 40 inclusive  
41 to 72 inclusive  
Minimum Thickness Inches  
1/2  
5/8  
3/4  
7/8  
1
1 1/8  
Page 38  
TABLE 20  
MINIMUM THICKNESS OF STEEL DISC WHEELS  
FOR MACHINES USING PLATE MOUNTED WHEELS HAVING THIN MOUNTING  
PLATES  
Abrasive Disc Diameter D (Inches)  
12 and smaller  
Minimum Thickness Pt (Inches)  
3/8  
1/2  
5/8  
3/4  
7/8  
14 to 16 inclusive  
17 to 18 inclusive  
19 to 26 inclusive  
27 to 36 inclusive  
TABLE 21  
STANDARD MAXIMUM SPEEDS IN SURFACE FEET PER MINUTE  
Inorganic Bonds  
Organic Bonds  
Types of Wheels  
(See Section 1 for Definitions)  
OPERATING SPEED SHALL NOT EXCEED:  
SFPM  
SFPM  
SFPM  
SFPM  
SFPM  
SFPM  
Type 1 – Straight Wheels – except  
classifications 6, 7, 9, 10, 11, 12 and 13  
below  
Type 4* – Taper Side Wheels  
Types 5, 7, 20, 21, 22, 23, 24, 25, 26  
Recessed, Dovetailed and/or relieved  
wheels. (Except Classification 7 below)  
1
5,500  
6,000  
6,500  
6,500  
8,000  
9,500  
Type 12 – Dish Wheels  
Type 13 – Saucer Wheels  
Types 16, 17, 18, 19 – Cones and Plugs  
Type 2 – Cylinder Wheels including plate  
mounted, inserted nut and projecting stud –  
Segments  
2
3
5,000  
4,500  
5,500  
5,000  
6,000  
6,000  
5,000  
6,000  
6,000  
7,500  
7,000  
8,500  
Cup Shape Tool Grinding Wheels (For  
Fixed Base Machines)  
Type 6 – Straight Side Cups  
Type 11 – Flaring Cups  
Cup Shape Snagging Wheels (For Portable  
Machines)  
Type 6 – Straight Side Cups  
Type 11 – Flaring Cups  
Abrasive Discs: Plate Mounted Inserted Nut  
and Projecting Stud:  
Solid or Segmented  
4
5
4,500  
5,500  
6,500  
6,000  
8,000  
9,500  
5,500  
X
6,000  
X
6,500  
X
5,500  
9,500  
7,000  
8,500  
Reinforced Wheels Type 1  
Max. Dia. 4”  
12,500  
16,000  
Max. Thickness 1/4"  
6†  
Max. Dia. 10”  
X
X
X
X
X
X
9,500  
9,500  
12,500  
12,500  
14,200  
12,500  
Max. Thickness 1/2"  
All Other Dias. and Thicknesses  
Page 39  
TABLE 21  
STANDARD MAXIMUM SPEEDS IN SURFACE FEET PER MINUTE  
Inorganic Bonds  
Organic Bonds  
Types of Wheels  
(See Section 1 for Definitions)  
OPERATING SPEED SHALL NOT EXCEED:  
SFPM  
SFPM  
SFPM  
SFPM  
9,500  
X
SFPM  
12,500  
9,500  
SFPM  
14,200  
11,000  
Reinforced Wheels – Types 27 and 28  
Max. Dia. 9”  
Max. Thickness 3/8”  
X
X
X
X
X
X
Max. Dia. 9” – Over 3/8” Thick  
Type 1 Wheels for Bench and Pedestal  
Grinders and Types 1 and 5 Surface  
Grinders in following sizes only.  
5,500  
6,325  
6,600  
6,500  
8,000  
9,500  
7
8
7” dia. up to 2” thick and up to 2” hole  
8” dia. up to 2” thick and up to 2” hole  
5,500  
X
6,325  
X
7,550  
6,500  
X
8,000  
X
9,500  
Diamond Wheels  
Cutting-Off – IAI, IAIR, IAIRS**  
16,000  
16,000  
Metal Bond  
Resin Bond  
Vitrified Bond  
X
X
X
X
X
X
12,000  
X
X
X
X
X
X
X
X
9,500  
X
6,500  
Cutting Off Wheels Type 1 and 27A  
Larger than 16” dia., Including Reinforced  
Organic  
Cutting-Off Wheels Type 1 and 27A  
16” dia., and smaller – Including Reinforced  
Organic  
9
X
X
X
X
X
X
9,500  
9,500  
12,000  
12,000  
14,200  
16,000  
10  
11  
12  
Thread and Flute Grinding Wheels  
8,000  
5,500  
10,000  
8,000  
12,000  
8,500  
8,000  
6,500  
10,000  
8,000  
12,000  
9,500  
Crankshaft and Camshaft Grinding Wheels  
Type 1 Snagging Wheels 16” dia. and  
Larger, Organic Bond, Non Reinforced  
Used on Specifically Designed Swing  
Frame and Mechanical Grinders  
Internal Wheels – Type 1 and 5 Maximum  
dia. 6”  
13  
14  
X
X
X
X
X
12,500  
9,500  
5,500  
8,000  
8,500  
6,500  
8,500  
* Non-standard Shape.  
† Classification 6 excludes cut-off wheels.  
** Standard Diamond Wheel Shapes.  
Page 40  
TABLE 22  
WHEEL MANUFACUTERS TESTING SPEEDS  
Operating Speed Surface  
Class of Wheel  
Minimum Test Factor*  
Feet Per Minute  
Cutting-off Wheels  
All speeds  
1.20  
1.25  
1.50  
All Bonds and Wheel Types  
(Except Cutting-off Wheels)  
Up to 5,000  
All Bonds and Wheel Types  
(Except Cutting-off wheels)  
Faster than 5,000  
* Actual operating speed shall be multiplied by this test factor to establish minimum speed  
at which wheels shall be tested by the wheel manufacturer.  
Page 41  
TABLE 23  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/32” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
W 141  
W 142  
W 143  
W 144  
W 145  
W 146  
W 147  
W 148  
W 149  
W 150  
W 151  
W 152  
W 153  
W 154  
W 155  
W 156  
W 157  
W 158  
W 159  
W 160  
W 161  
W 162  
W 165  
W 166  
W 167  
W 168  
W 169  
W 170  
W 171  
W 172  
W 173  
W 174  
W 175  
W 176  
3/32  
3/32  
1/8  
5/32  
1/4  
93,750  
93,750  
93,750  
93,750  
88,500  
81,000  
93,750  
93,750  
90,750  
93,750  
93,750  
83,250  
73,500  
66,000  
78,000  
93,750  
93,750  
93,750  
78,000  
69,000  
66,000  
57,000  
93,000  
84,750  
61,500  
56,250  
48,000  
39,750  
27,750  
85,500  
71,250  
54,000  
41,250  
33,750  
53,250  
53,250  
53,250  
53,250  
49,500  
43,750  
53,250  
53,250  
50,250  
53,250  
53,250  
47,250  
42,000  
38,250  
44,250  
53,250  
53,250  
53,250  
44,250  
42,000  
39,750  
34,500  
51,750  
48,750  
39,000  
33,750  
28,500  
26,250  
19,500  
48,750  
46,500  
32,250  
24,000  
21,000  
37,500  
37,500  
37,500  
37,500  
35,250  
31,500  
37,500  
37,500  
36,000  
37,500  
37,500  
33,000  
28,500  
25,500  
30,750  
37,500  
37,500  
37,500  
30,750  
27,750  
24,750  
23,250  
37,500  
28,500  
24,750  
22,500  
20,250  
16,500  
13,500  
33,750  
30,000  
21,000  
18,000  
15,750  
25,500  
25,500  
25,500  
25,500  
24,000  
22,500  
25,500  
25,500  
24,750  
25,500  
25,500  
23,250  
21,000  
18,750  
21,750  
25,500  
25,500  
25,500  
21,750  
18,750  
17,250  
16,500  
25,500  
19,500  
18,000  
16,500  
15,000  
12,750  
10,500  
24,000  
19,500  
15,000  
12,750  
12,000  
16,500  
16,500  
16,500  
16,500  
15,750  
15,000  
16,500  
16,500  
15,750  
16,500  
16,500  
15,000  
13,500  
12,750  
14,250  
16,500  
16,500  
16,500  
14,250  
13,500  
12,750  
11,250  
16,500  
14,250  
12,000  
12,000  
11,250  
9,750  
1/8  
1/8  
1/4  
1/8  
3/8  
1/8  
1/2  
5/32  
5/32  
5/32  
3/16  
3/16  
3/16  
3/16  
3/16  
13/64  
1/4  
1/32  
1/16  
1/4  
1/16  
1/8  
1/4  
3/8  
1/2  
1/4  
1/32  
1/16  
1/8  
1/4  
1/4  
1/4  
3/16  
1/4  
1/4  
1/4  
5/16  
3/8  
1/4  
5/16  
5/16  
5/16  
5/16  
5/16  
5/16  
5/16  
3/8  
1/16  
1/8  
1/4  
5/16  
3/8  
1/2  
3/4  
8,250  
1/16  
1/8  
15,000  
12,750  
10,500  
9,750  
3/8  
3/8  
1/4  
3/8  
3/8  
3/8  
1/2  
9,000  
Page 42  
TABLE 24  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
W 143  
W 144  
W 145  
W 146  
W 151  
W 152  
W 153  
W 154  
W 157  
W 158  
W 159  
W 160  
W 161  
W 162  
W 163  
W 164  
W 165  
W 166  
W 167  
W 168  
W 169  
W 170  
W 171  
W 172  
W 173  
W 174  
W 175  
W 176  
W 177  
W 178  
W 181  
W 182  
W 183  
W 184  
W 185  
W 186  
W 187  
W 190  
W 191  
1/8  
1/8  
1/8  
1/4  
3/8  
1/2  
1/8  
1/4  
3/8  
1/2  
1/16  
1/8  
3/16  
1/4  
5/16  
3/8  
1/2  
3/4  
1/16  
1/8  
1/4  
5/16  
3/8  
1/2  
3/4  
1/16  
1/8  
1/4  
3/8  
1/2  
3/4  
1
105,000  
105,000  
105,000  
105,000  
105,000  
105,000  
80,850  
70,500  
123,000  
105,000  
92,400  
81,370  
77,250  
68,400  
60,000  
45,900  
107,400  
96,970  
75,000  
68,400  
61,650  
52,500  
37,120  
99,370  
87,600  
69,000  
54,000  
45,370  
33,750  
26,250  
76,390  
73,500  
51,750  
41,020  
34,500  
26,250  
20,620  
61,120  
58,870  
64,500  
64,500  
64,500  
64,500  
64,500  
64,500  
52,500  
46,500  
65,525  
64,500  
57,370  
51,000  
45,970  
42,370  
38,020  
30,000  
62,470  
57,000  
47,570  
41,770  
37,720  
33,000  
25,500  
59,250  
53,250  
41,250  
33,000  
28,500  
23,250  
18,750  
55,500  
43,650  
31,870  
26,400  
22,500  
17,400  
13,870  
48,000  
34,500  
46,650  
46,650  
46,650  
46,650  
46,650  
46,650  
37,500  
31,500  
47,770  
46,650  
39,370  
34,120  
30,900  
28,870  
26,250  
21,750  
41,250  
35,620  
31,120  
28,650  
27,000  
23,020  
18,750  
41,020  
35,250  
27,750  
24,150  
21,000  
17,620  
14,250  
36,750  
29,100  
22,500  
19,500  
16,870  
12,750  
10,120  
31,500  
25,120  
32,400  
32,400  
32,400  
32,400  
32,400  
32,400  
26,250  
21,970  
33,150  
32,400  
27,900  
24,000  
22,500  
20,850  
18,750  
15,900  
29,250  
25,120  
22,500  
21,000  
19,870  
16,650  
14,620  
29,250  
24,750  
20,400  
18,000  
15,900  
13,650  
10,870  
25,500  
20,770  
17,250  
15,000  
13,120  
9,750  
21,370  
21,370  
21,370  
21,370  
21,370  
21,370  
17,620  
15,220  
21,750  
21,370  
18,900  
16,870  
16,120  
15,000  
13,870  
11,850  
20,250  
18,000  
15,750  
15,000  
14,250  
12,600  
10,020  
20,250  
17,250  
15,000  
13,500  
12,150  
10,350  
8,250  
1/8  
1/8  
5/16  
3/16  
3/16  
3/16  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
5/16  
5/16  
5/16  
5/16  
5/16  
5/16  
5/16  
3/8  
3/8  
3/8  
3/8  
3/8  
3/8  
3/8  
1/2  
1/16  
1/8  
1/4  
3/8  
1/2  
3/4  
1
17,850  
15,450  
12,900  
11,400  
9,900  
1/2  
1/2  
1/2  
1/2  
1/2  
8,020  
1/2  
7,870  
6,370  
5/8  
1/16  
1/8  
22,650  
18,900  
16,870  
14,250  
5/8  
Page 43  
TABLE 24  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
W 192  
W 193  
W 194  
W 195  
W 196  
W 199  
W 200  
W 201  
W 202  
W 203  
W 204  
W 210  
W 211  
W 212  
W 213  
W 215  
W 216  
5/8  
5/8  
5/8  
5/8  
5/8  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
7/8  
7/8  
7/8  
7/8  
1
1/4  
3/8  
1/2  
3/4  
1
43,120  
32,250  
29,400  
22,120  
17,620  
50,930  
50,930  
38,250  
30,600  
25,500  
18,900  
43,650  
43,650  
33, 750  
27,000  
38,200  
30,520  
27,370  
23,020  
19,120  
14,250  
11,620  
44,770  
33,520  
24,370  
19,500  
15,900  
12,000  
35,250  
27,900  
20,400  
16,870  
24,900  
18,600  
19,870  
16,500  
13,500  
10,120  
8,100  
15,220  
12,520  
10,500  
7,650  
11,620  
9,750  
8,250  
6,150  
5,100  
15,750  
13,350  
9,970  
7,800  
6,600  
5,250  
14,320  
12,220  
9,000  
6,600  
10,500  
7,500  
6,150  
1/16  
1/8  
1/4  
3/8  
1/2  
3/4  
1/16  
1/8  
1/4  
3/8  
1/8  
1/4  
30,000  
23,850  
17,400  
13,500  
10,870  
8,400  
21,750  
17,850  
13,270  
10,120  
8,250  
6,220  
25,720  
20,400  
14,400  
11,250  
18,000  
12,750  
18,900  
15,820  
11,020  
8,250  
13,870  
9,520  
1
Page 44  
TABLE 25  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/16” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
W 158  
W 159  
W 160  
W 161  
W 162  
W 163  
W 164  
W 166  
W 167  
W 168  
W 169  
W 170  
W 171  
W 173  
W 174  
W 175  
W 176  
W 177  
W 178  
W 182  
W 183  
W 184  
W 185  
W 186  
W 187  
W 188  
W 189  
W 191  
W 192  
W 193  
W 194  
W 195  
W 196  
W 197  
W 200  
W 201  
W 202  
W 203  
W 204  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
1/4  
5/16  
5/16  
5/16  
5/16  
5/16  
5/16  
3/8  
3/8  
3/8  
3/8  
3/8  
3/8  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
5/8  
5/8  
5/8  
5/8  
5/8  
5/8  
5/8  
3/4  
3/4  
3/4  
3/4  
3/4  
1/8  
3/16  
1/4  
5/16  
3/8  
1/2  
3/4  
1/8  
1/4  
5/16  
3/8  
1/2  
3/4  
1/8  
1/4  
3/8  
1/2  
3/4  
1
121,500  
112,500  
103,500  
93,750  
89,250  
78,750  
62,250  
118,500  
100,500  
93,000  
87,370  
76,500  
57,000  
101,900  
98,850  
81,750  
66,750  
54,000  
42,000  
76,390  
75,000  
57,750  
49,870  
39,000  
32,250  
22,870  
17,250  
61,120  
61,120  
52,500  
44,400  
34,500  
25,870  
14,770  
50,930  
50,930  
45,750  
39,750  
29,250  
66,750  
63,000  
60,000  
58,120  
56,250  
52,500  
39,750  
65,250  
58,500  
57,000  
55,350  
47,250  
37,500  
65,250  
57,750  
50,620  
43,120  
36,000  
29,250  
56,250  
47,400  
39,750  
33,750  
28,120  
23,250  
17,620  
13,500  
51,370  
43,500  
34,870  
31,120  
24,000  
18,900  
11,770  
48,750  
37,500  
31,500  
27,370  
20,250  
48,000  
47,250  
44,250  
42,750  
41,250  
39,000  
30,000  
47,250  
43,500  
42,000  
40,870  
34,500  
27,750  
46,500  
42,750  
36,750  
31,350  
26,250  
22,500  
39,870  
33,370  
29,250  
25,500  
21,370  
18,370  
13,870  
10,500  
36,370  
30,750  
25,500  
23,400  
18,370  
15,000  
8,700  
36,000  
34,650  
33,000  
31,870  
30,000  
28,870  
23,250  
35,250  
35,620  
30,750  
28,880  
25,500  
21,750  
34,500  
32,250  
27,750  
23,620  
20,250  
17,250  
29,250  
24,900  
21,750  
19,500  
15,750  
13,500  
11,250  
8,620  
26,250  
25,120  
24,000  
22,500  
21,750  
20,620  
16,500  
25,500  
23,250  
22,120  
21,000  
18,750  
15,750  
24,750  
23,250  
20,250  
17,400  
15,000  
12,900  
21,750  
18,750  
15,750  
14,620  
12,000  
10,500  
----  
1/8  
1/4  
3/8  
1/2  
3/4  
1
1 1/2  
2
----  
1/8  
1/4  
3/8  
1/2  
3/4  
1
27,000  
23,400  
18,750  
18,000  
14,250  
11,620  
7,270  
20,250  
18,000  
15,000  
13,500  
10,500  
9,370  
2
----  
1/8  
1/4  
3/8  
1/2  
3/4  
33,750  
27,900  
24,370  
20,620  
15,000  
25,500  
21,370  
18,000  
15,900  
12,000  
19,500  
16,500  
13,870  
12,000  
9,370  
Page 45  
TABLE 25  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/16” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
W 205  
W 206  
W 207  
W 208  
W 211  
W 212  
W 213  
W 215  
W 216  
W 217  
W 218  
W 219  
W 220  
W 221  
W 222  
W 225  
W 226  
W 227  
W 228  
W 229  
W 230  
W 231  
W 232  
W 235  
W 236  
W 237  
W 238  
3/4  
3/4  
3/4  
3/4  
7/8  
7/8  
7/8  
1
1
1 1/4  
1 1/2  
2
24,750  
19,500  
16,500  
12,750  
43,650  
43,650  
42,370  
38,200  
38,200  
38,200  
32,700  
25,120  
19,500  
13,120  
9,000  
17,250  
14,250  
12,370  
9,370  
12,750  
11,620  
9,750  
10,500  
9,000  
8,620  
6,750  
----  
7,870  
7,500  
6,000  
----  
1/8  
1/4  
3/8  
1/8  
1/4  
3/8  
1/2  
3/4  
1
43,650  
34,500  
28,120  
38,200  
33,750  
27,000  
22,120  
17,620  
14,250  
9,370  
31,870  
25,870  
21,370  
31,120  
24,750  
19,870  
16,870  
12,900  
11,250  
7,120  
24,000  
19,870  
16,500  
23,620  
19,120  
15,750  
12,900  
9,900  
18,370  
14,620  
12,370  
18,000  
14,250  
12,000  
10,350  
8,400  
7,120  
----  
1
1
1
1
1
8,620  
1
1 1/2  
2
6,000  
1
7,120  
5,620  
4,870  
----  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
1/4  
3/8  
1/2  
3/4  
1
30,560  
30,560  
27,750  
20,620  
16,500  
13,270  
10,270  
7,500  
28,870  
22,120  
19,120  
14,620  
12,000  
9,150  
21,220  
16,350  
13,950  
11,020  
8,620  
16,270  
12,750  
10,650  
8,770  
12,300  
10,270  
8,700  
7,120  
5,770  
----  
6,900  
1 1/4  
1 1/2  
2
6,970  
5,700  
7,270  
6,000  
5,100  
----  
6,000  
4,870  
4,500  
----  
1/4  
1/2  
1
25,470  
25,470  
15,750  
9,900  
24,900  
18,750  
11,250  
6,970  
18,900  
13,870  
7,870  
15,150  
10,500  
6,370  
11,770  
8,620  
5,620  
----  
1 1/2  
5,470  
4,870  
Page 46  
TABLE 26  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/4” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
3”  
4”  
5”  
W 176  
W 177  
W 178  
W 179  
W 182  
W 183  
W 184  
W 185  
W 186  
W 187  
W 188  
W 189  
W 190  
W 191  
W 192  
W 193  
W 194  
W 195  
W 196  
W 197  
W 198  
W 201  
W 202  
W 203  
W 204  
W 205  
W 206  
W 207  
W 208  
W 209  
W 211  
W 212  
W 213  
W 215  
W 216  
W 217  
W 218  
W 219  
3/8  
3/8  
3/8  
3/8  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
1/2  
5/8  
5/8  
5/8  
5/8  
5/8  
5/8  
5/8  
5/8  
5/8  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
7/8  
7/8  
7/8  
1
1/2  
3/4  
1
81,000  
66,000  
55,200  
45,750  
76,390  
76,390  
71,250  
61,500  
51,000  
40,500  
30,370  
24,000  
61,120  
61,120  
61,120  
61,120  
56,400  
46,500  
35,250  
21,000  
16,500  
50,930  
50,930  
50,930  
42,750  
34,500  
28,720  
24,000  
18,750  
15,000  
43,650  
43,650  
43,650  
38,200  
38,200  
38,200  
38,200  
35,100  
54,379  
46,500  
40,500  
33,750  
62,400  
54,750  
47,620  
42,000  
36,370  
30,000  
24,000  
18,750  
61,120  
60,000  
51,750  
45,500  
39,750  
32,400  
27,000  
16,500  
12,900  
50,930  
44,100  
36,370  
30,750  
25,870  
21,520  
18,520  
15,370  
12,150  
43,650  
43,650  
40,870  
38,200  
38,200  
38,200  
32,770  
24,520  
42,000  
32,250  
30,000  
25,720  
45,750  
40,500  
35,020  
31,500  
27,750  
24,000  
18,900  
15,000  
48,000  
44,250  
38,400  
33,370  
29,400  
24,900  
21,300  
12,900  
10,870  
38,100  
32,400  
27,750  
23,250  
19,500  
17,020  
14,620  
12,000  
10,500  
42,900  
35,100  
29,400  
38,200  
33,750  
28,500  
24,900  
18,750  
33,000  
27,370  
23,250  
19,720  
35,400  
31,120  
27,000  
24,000  
21,220  
18,750  
15,000  
12,150  
31,500  
34,500  
29,770  
25,870  
22,720  
19,720  
16,870  
10,870  
8,700  
25,500  
21,000  
17,250  
15,300  
27,250  
24,000  
20,850  
18,370  
16,120  
14,250  
12,000  
9,900  
20,400  
16,800  
13,800  
12,240  
22,020  
19,200  
16,680  
14,700  
12,900  
11,400  
9,600  
13,260  
10,920  
8,970  
7,960  
14,310  
12,480  
10,840  
9,560  
8,390  
7,410  
6,240  
5,150  
15,090  
14,040  
12,140  
10,450  
9,050  
8,000  
6,830  
4,520  
3,640  
11,700  
10,060  
8,780  
7,290  
6,240  
5,620  
5,150  
4,160  
3,540  
13,650  
11,120  
9,560  
13,260  
10,530  
9,050  
7,720  
6,240  
9,550  
7,860  
6,460  
5,730  
10,300  
8,990  
7,800  
6,880  
6,040  
5,340  
4,490  
3,710  
10,800  
10,110  
8,740  
7,520  
6,520  
5,760  
4,920  
3,250  
2,620  
8,420  
7,240  
6,320  
5,250  
4,490  
4,050  
3,710  
3,000  
2,550  
9,820  
8,010  
6,880  
9,550  
7,580  
6,520  
5,560  
4,490  
1 1/4  
1/8  
1/4  
3/8  
1/2  
3/4  
1
1 1/2  
2
7,920  
1/16  
1/8  
1/4  
3/8  
1/2  
3/4  
1
29,020  
27,000  
23,250  
20,100  
17,400  
15,370  
13,120  
8,700  
23,220  
21,600  
18,680  
16,080  
13,920  
12,300  
10,500  
6,960  
2
2 1/2  
1/4  
3/8  
1/2  
3/4  
1
7,000  
5,600  
29,020  
25,120  
21,750  
18,000  
15,000  
13,500  
12,000  
9,900  
22,500  
19,350  
16,870  
14,020  
12,000  
10,800  
9,900  
18,000  
15,480  
13,500  
11,220  
9,600  
1 1/4  
1 1/2  
2
8,640  
7,920  
8,000  
6,400  
2 1/2  
1/8  
1/4  
3/8  
1/8  
1/4  
3/8  
1/2  
3/4  
8,400  
6,800  
5,440  
33,000  
27,600  
23,400  
33,750  
26,250  
22,500  
19,500  
15,000  
26,250  
21,370  
18,370  
25,500  
20,250  
17,400  
14,850  
12,000  
21,000  
17,100  
14,700  
20,400  
16,200  
13,920  
11,880  
9,600  
1
1
1
1
Page 47  
TABLE 26  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/4” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
3”  
4”  
5”  
W 220  
W 221  
W 222  
W 223  
W 225  
W 226  
W 227  
W 228  
W 229  
W 230  
W 231  
W 232  
W 235  
W 236  
W 237  
W 238  
W 239  
W 240  
W 241  
W 242  
W 243  
W 244  
W 245  
W 246  
1
1
1 1/2  
2
25,500  
19,120  
15,900  
12,370  
30,560  
30,560  
30,560  
30,520  
24,000  
20,400  
17,620  
14,250  
25,470  
25,470  
22,500  
15,600  
12,750  
10,500  
9,000  
19,120  
14,620  
12,370  
9,900  
15,750  
12,000  
9,750  
12,370  
10,500  
8,620  
10,500  
8,400  
6,900  
5,500  
18,750  
15,750  
14,100  
11,400  
9,900  
8,400  
7,200  
6,000  
17,620  
13,650  
9,520  
6,600  
5,100  
4,400  
3,900  
8,800  
6,300  
5,030  
4,250  
3,700  
8,400  
6,720  
5,520  
4,400  
15,000  
12,600  
11,280  
9,120  
7,920  
6,720  
5,760  
4,800  
14,100  
10,920  
7,620  
5,280  
4,080  
3,520  
3,120  
7,040  
5,040  
4,000  
3,400  
2,960  
5,460  
4,370  
3,590  
2,860  
9,750  
8,190  
7,330  
5,930  
5,150  
4,370  
3,740  
3,120  
9,170  
7,100  
4,950  
3,430  
2,650  
2,290  
2,030  
4,580  
3,280  
2,600  
2,210  
1,920  
3,930  
3,150  
2,580  
2,060  
7,020  
5,900  
5,280  
4,270  
3,710  
3,150  
2,690  
2,250  
6,600  
5,110  
3,560  
2,470  
1,910  
1,650  
1,460  
3,300  
2,360  
1,870  
1,590  
1,380  
1
1
1
2 1/2  
1/4  
3/8  
1/2  
3/4  
1
8,620  
6,900  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
2
30,560  
30,560  
29,620  
22,500  
18,750  
15,900  
13,500  
10,650  
25,470  
25,470  
17,620  
12,000  
9,900  
30,560  
26,250  
22,650  
17,850  
15,370  
12,750  
10,650  
9,000  
24,000  
20,100  
18,000  
14,250  
12,000  
10,500  
9,000  
1 1/4  
1 1/2  
2
7,500  
1/4  
1/2  
1
25,470  
21,750  
13,270  
9,750  
22,720  
17,250  
10,870  
8,250  
1 1/2  
2
8,000  
6,400  
2 1/2  
3
8,400  
6,800  
5,500  
7,250  
6,000  
4,800  
1
19,100  
14,500  
11,750  
9,600  
15,950  
12,750  
10,500  
7,250  
11,750  
9,800  
10,000  
7,800  
2
1 1/2  
2
2
7,500  
6,200  
2
2 1/2  
3
6,400  
5,300  
2
8,250  
6,750  
5,600  
4,600  
Page 48  
TABLE 27  
GROUP W – (PLAIN WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/8” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
3”  
4”  
5”  
W 185  
W 186  
W 187  
W 188  
W 189  
W 194  
W 195  
W 196  
W 197  
W 198  
W 203  
W 204  
W 205  
W 206  
W 207  
W 208  
W 209  
W 218  
W 219  
W 220  
W 221  
W 222  
W 223  
W 227  
W 228  
W 229  
W 230  
W 231  
W 232  
W 236  
W 237  
W 238  
W 239  
W 240  
W 241  
W 242  
W 243  
W 244  
W 245  
1/2  
1/2  
1/2  
1/2  
1/2  
5/8  
5/8  
5/8  
5/8  
5/8  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
3/4  
1
1/2  
3/4  
1
76,390  
76,390  
76,390  
60,740  
48,000  
61,120  
61,120  
61,120  
42,000  
33,000  
50,930  
50,930  
50,930  
50,930  
48,000  
37,500  
30,000  
38,200  
38,200  
38,200  
38,200  
31,800  
24,740  
30,560  
30,560  
30,560  
30,560  
30,560  
28,500  
25,470  
25,470  
25,470  
25,470  
21,000  
18,000  
19,100  
19,100  
19,100  
19,100  
76,390  
72,740  
60,000  
48,000  
37,500  
61,120  
61,120  
54,000  
33,000  
25,800  
50,930  
50,930  
50,930  
43,040  
37,040  
30,740  
24,300  
38,200  
38,200  
38,200  
29,240  
24,740  
19,800  
30,560  
30,560  
30,560  
30,560  
27,000  
21,300  
25,470  
25,470  
24,000  
19,800  
16,800  
14,500  
19,100  
19,100  
19,100  
14,500  
63,000  
55,500  
48,000  
37,800  
30,000  
58,880  
49,800  
42,600  
25,800  
21,740  
50,930  
46,500  
39,000  
34,040  
29,240  
24,000  
21,000  
38,200  
37,500  
31,500  
24,000  
19,500  
17,240  
30,560  
30,560  
30,560  
25,500  
21,300  
18,000  
25,470  
25,470  
19,500  
16,000  
13,600  
12,000  
19,100  
19,100  
15,000  
12,800  
48,000  
42,440  
37,500  
30,000  
24,300  
45,440  
39,440  
33,740  
21,740  
17,400  
43,500  
36,000  
30,000  
27,000  
24,000  
19,800  
16,800  
38,200  
30,000  
24,740  
21,000  
17,240  
13,800  
30,560  
28,500  
24,000  
21,000  
18,000  
15,000  
25,470  
21,470  
16,500  
12,800  
11,000  
9,600  
36,740  
32,240  
28,500  
24,000  
19,800  
34,800  
30,740  
26,240  
17,400  
14,000  
33,740  
28,040  
24,000  
21,600  
19,800  
16,000  
13,600  
29,700  
24,000  
21,000  
16,800  
13,800  
11,000  
28,200  
22,800  
19,800  
16,800  
14,400  
12,000  
25,470  
19,040  
13,200  
10,200  
8,800  
29,400  
25,800  
22,800  
19,200  
15,840  
27,840  
24,600  
21,000  
13,970  
11,200  
27,000  
22,440  
19,200  
17,280  
15,840  
12,800  
10,880  
23,760  
19,200  
16,800  
13,440  
11,040  
8,800  
19,120  
16,780  
14,820  
12,480  
10,300  
18,100  
16,000  
13,660  
9,040  
13,760  
12,080  
10,680  
8.980  
7,420  
13,040  
11,520  
9,840  
6,500  
5,240  
12,640  
10,500  
8,980  
8,100  
7,420  
6,000  
5,100  
11,120  
8,980  
7,860  
6,300  
5,160  
4,120  
10,560  
8,540  
7,420  
6,300  
5,380  
4,500  
10,220  
7,120  
4,940  
3,820  
3,300  
2,920  
6,600  
4,720  
3,740  
3,180  
1 1/2  
2
1/2  
3/4  
1
2
2 1/2  
1/2  
3/4  
1
7,280  
17,560  
14,580  
12,480  
11,240  
10,300  
8,320  
1 1/4  
1 1/2  
2
2 1/2  
1/2  
3/4  
1
7,080  
15,440  
12,480  
10,920  
8,740  
1
1
1
1 1/2  
2
1
7,180  
1
2 1/2  
1/2  
3/4  
1
5,720  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/4  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
1 1/2  
2
22,560  
18,240  
15,840  
13,440  
11,520  
9,600  
14,660  
11,860  
10,300  
8,740  
1 1/4  
1 1/2  
2
7,480  
6,240  
1/2  
1
21,840  
15,240  
10,560  
8,160  
14,200  
9,900  
1 1/2  
2
6,860  
5,300  
2 1/2  
3
7,040  
4,580  
7,800  
6,240  
4,060  
1
19,100  
15,600  
12,400  
10,600  
17,600  
12,600  
10,000  
8,500  
14,080  
10,080  
8,000  
9,160  
2
1 1/2  
2
6,560  
2
5,200  
2
2 1/2  
6,800  
4,420  
Page 49  
W 246  
2
3
16,500  
13,500  
11,200  
9,200  
7,400  
5,920  
3,840  
2,760  
Page 50  
TABLE 28  
GROUP B – (SHAPED WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 3/32” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
B 43  
B 44  
B 45  
B 46  
B 47  
B 53  
B 55  
B 63  
B 64  
B 65  
B 70  
B 71  
B 72  
B 73  
B 74  
B 81  
B 82  
B 83  
B 84  
B 92  
B 93  
B 94  
B 95  
B 96  
B 97  
B 98  
B 104  
B 105  
B 106  
B 112  
B 113  
B 114  
B 115  
B 122  
B 123  
B 124  
1/4  
7/32  
3/16  
1/8  
5/16  
3/8  
67,500  
57,000  
86,250  
87,000  
87,000  
49,500  
87,000  
76,500  
87,000  
87,000  
50,930  
61,120  
60,750  
60,750  
87,000  
50,930  
67,500  
72,750  
87,000  
67,500  
87,000  
87,000  
87,000  
87,000  
87,000  
87,000  
57,000  
86,250  
87,000  
37,500  
67,500  
57,000  
87,000  
51,000  
86,250  
87,000  
41,250  
34,500  
50,250  
52,500  
52,500  
30,750  
52,500  
46,500  
52,500  
52,500  
33,750  
39,000  
35,250  
35,250  
52,500  
33,750  
41,250  
43,500  
52,500  
41,250  
52,500  
52,500  
52,500  
52,500  
52,500  
52,500  
34,500  
50,250  
52,500  
23,250  
41,250  
34,500  
52,500  
30,750  
50,250  
52,500  
27,000  
22,500  
35,250  
36,750  
36,750  
20,250  
36,750  
30,750  
36,750  
36,750  
21,750  
24,750  
23,250  
23,250  
36,750  
21,750  
27,000  
27,750  
36,750  
27,000  
36,750  
36,750  
36,750  
36,750  
36,750  
36,750  
22,500  
35,250  
36,750  
16,500  
27,000  
22,500  
36,750  
21,000  
35,250  
36,750  
18,750  
16,500  
24,000  
24,750  
24,750  
14,250  
24,750  
21,750  
24,750  
24,750  
15,750  
17,250  
16,500  
16,500  
24,750  
15,750  
18,750  
19,500  
24,750  
18,750  
24,750  
24,750  
24,750  
24,750  
24,750  
24,750  
16,500  
24,000  
24,750  
12,750  
18,750  
16,500  
24,750  
15,000  
24,000  
24,750  
12,750  
11,250  
15,000  
16,500  
16,500  
10,500  
16,500  
14,250  
16,500  
16,500  
11,250  
12,750  
12,000  
12,000  
16,500  
11,250  
12,750  
12,750  
16,500  
12,750  
16,500  
16,500  
16,500  
16,500  
16,500  
16,500  
11,250  
15,000  
16,500  
9,000  
5/16  
5/16  
5/32  
5/8  
1/8  
1/4  
1/8  
1/4  
1/4  
3/16  
1/16  
1/8  
1/4  
1/8  
3/4  
1/8  
5/8  
1/8  
1/2  
1/8  
1/2  
1/8  
7/32  
3/4  
3/32  
3/16  
1/4  
1/2  
3/8  
3/16  
3/16  
1/4  
5/16  
1/4  
3/16  
11/64  
1/8  
3/16  
3/32  
3/16  
1/4  
1/8  
1/8  
3/8  
3/32  
5/16  
1/4  
1/4  
3/8  
1/4  
1/8  
7/64  
1/2  
3/8  
1/4  
1/4  
12,750  
11,250  
16,500  
10,500  
15,000  
16,500  
7/32  
3/32  
3/8  
3/8  
1/8  
3/8  
3/16  
1/8  
3/16  
1/8  
Page 51  
TABLE 29  
GROUP B – (SHAPED WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
B 41  
B 42  
B 43  
B 44  
B 45  
B 46  
B 47  
B 51  
B 52  
B 53  
B 54  
B 55  
B 61  
B 62  
B 63  
B 64  
B 65  
B 70  
B 71  
B 72  
B 73  
B 74  
B 81  
B 82  
B 83  
B 84  
B 91  
B 92  
B 93  
B 94  
B 95  
B 96  
B 97  
B 98  
B 101  
B 102  
B 103  
5/8  
½
5/8  
3/4  
33,750  
33,750  
81,370  
68,400  
104,250  
105,000  
105,000  
45,370  
43,370  
60,000  
60,000  
105,000  
38,250  
41,020  
92,400  
105,000  
105,000  
50,930  
61,120  
73,500  
73,500  
105,000  
50,930  
76,390  
87,600  
105,000  
34,500  
81,370  
105,000  
105,000  
105,000  
105,000  
105,000  
105,000  
33,750  
45,370  
61,120  
23,250  
23,250  
51,000  
42,370  
61,870  
64,500  
64,500  
28,500  
28,500  
38,020  
38,020  
64,500  
24,370  
26,400  
57,370  
64,500  
64,500  
41,250  
48,000  
43,650  
43,650  
64,500  
41,250  
51,000  
53,250  
64,500  
22,500  
51,000  
64,500  
64,500  
64,500  
64,500  
64,500  
64,500  
23,250  
28,500  
41,250  
17,620  
17,620  
34,120  
28,870  
44,620  
46,650  
46,650  
21,000  
21,000  
26,250  
26,250  
46,550  
17,400  
19,500  
39,370  
46,650  
46,650  
27,750  
31,500  
29,100  
29,100  
46,650  
27,750  
34,120  
35,250  
46,650  
16,870  
34,120  
46,650  
46,650  
46,650  
46,650  
46,650  
46,650  
17,620  
21,000  
27,750  
13,650  
13,650  
24,000  
20,850  
30,900  
32,400  
32,400  
15,900  
15,900  
18,750  
18,750  
32,400  
13,270  
15,000  
27,900  
32,400  
32,400  
20,400  
22,650  
20,770  
20,700  
32,400  
20,400  
24,000  
24,750  
32,400  
13,120  
24,000  
32,400  
32,400  
32,400  
32,400  
32,400  
32,400  
13,650  
15,900  
20,400  
10,350  
10,350  
16,870  
15,000  
20,250  
21,370  
21,370  
12,150  
12,150  
13,870  
13,870  
21,370  
9,970  
¼
5/16  
3/8  
7/32  
3/16  
1/8  
1/8  
7/16  
3/8  
¼
5/16  
5/16  
5/32  
3/4  
3/4  
5/8  
¼
1/2  
1/8  
3/4  
1/2  
1/4  
1/4  
1/8  
3/4  
5/8  
1/2  
1/2  
7/32  
3/4  
1/2  
3/8  
5/16  
1/2  
1/4  
3/16  
11/64  
1/8  
1/8  
1/8  
3/32  
5/8  
5/8  
5/8  
1/4  
5/16  
3/8  
11,400  
18,900  
21,370  
21,370  
15,000  
16,870  
15,450  
15,450  
21,370  
15,000  
16,870  
17,250  
21,370  
9,900  
3/16  
1/16  
1/8  
1/8  
1/8  
1/8  
1/8  
3/32  
3/16  
1/4  
3/16  
3/16  
5/8  
1/4  
16,870  
21,370  
21,370  
21,370  
21,370  
21,370  
21,370  
10,350  
12,150  
15,000  
3/16  
3/32  
3/16  
1/4  
3/8  
1/4  
11/16  
1/2  
3/16  
Page 52  
TABLE 29  
GROUP B – (SHAPED WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/8” MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
B 104  
B 105  
B 106  
B 111  
B 112  
B 113  
B 114  
B 115  
B 121  
B 122  
B 123  
B 124  
B 131  
B 132  
B 133  
B 134  
B 135  
B 136  
5/16  
1/4  
3/8  
1/4  
68,400  
104,250  
105,000  
33,750  
45,370  
81,370  
68,400  
105,000  
45,370  
61,650  
104,250  
105,000  
34,500  
45,370  
54,000  
61,650  
60,000  
77,250  
42,370  
61,870  
64,500  
23,250  
28,500  
51,000  
42,370  
64,500  
28,500  
37,720  
61,820  
64,500  
22,500  
28,500  
33,000  
37,720  
38,020  
45,920  
28,870  
44,620  
46,650  
17,620  
21,000  
34,120  
28,870  
46,650  
21,000  
27,000  
44,620  
46,650  
16,870  
21,000  
24,150  
27,000  
26,250  
30,900  
20,850  
30,900  
32,400  
13,650  
15,900  
24,000  
20,850  
32,400  
15,900  
19,870  
30,900  
32,400  
13,120  
15,900  
18,000  
19,870  
18,750  
22,500  
15,000  
20,250  
21,370  
10,350  
12,150  
16,870  
15,000  
21,370  
12,150  
14,250  
20,250  
21,370  
9,900  
1/8  
7/64  
11/16  
1/2  
7/16  
3/8  
1/4  
1/4  
7/32  
3/32  
1/2  
3/8  
1/8  
1/2  
3/8  
3/8  
3/16  
1/8  
3/16  
1/8  
1/2  
1/2  
3/8  
1/2  
12,150  
13,500  
14,250  
13,870  
16,120  
3/8  
3/8  
5/16  
1/4  
3/8  
1/2  
1/4  
5/16  
Page 53  
TABLE 30  
GROUP B – (SHAPED WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/4" MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
B 41  
B 42  
5/8  
1/2  
7/16  
3/8  
3/4  
1/2  
5/8  
1/2  
1/2  
1/2  
5/8  
5/8  
7/16  
3/8  
1/2  
1/2  
3/8  
5/8  
3/4  
61,120  
61,120  
81,000  
81,000  
50,930  
71,250  
61,120  
76,390  
76,390  
61,500  
61,120  
61,120  
66,000  
81,000  
76,390  
61,500  
81,000  
46,500  
46,500  
54,370  
54,370  
50,930  
47,620  
61,120  
62,400  
62,400  
42,000  
46,500  
54,370  
46,500  
54,370  
54,370  
42,000  
54,370  
35,250  
35,250  
42,000  
42,000  
38,100  
35,020  
48,000  
45,750  
45,750  
31,500  
35,250  
42,000  
35,250  
42,000  
42,000  
31,500  
42,000  
27,370  
27,370  
33,000  
33,000  
29,020  
27,000  
37,500  
35,400  
35,400  
24,000  
27,370  
33,000  
27,370  
33,000  
33,000  
24,000  
33,000  
21,000  
21,000  
25,500  
25,500  
22,500  
20,850  
29,020  
27,520  
27,520  
18,370  
21,000  
25,500  
21,000  
25,500  
25,500  
18,370  
25,500  
B 51  
3/4  
B 52  
3/4  
B 61  
5/16  
3/8  
B 62  
B 71  
1/8  
B 72  
1/8  
B 73  
1/8  
B 91  
5/8  
B 101  
B 102  
B 111  
B 112  
B 121  
B 131  
B 132  
11/16  
1/2  
11/16  
1/2  
1/2  
1/2  
1/2  
Page 54  
TABLE 31  
GROUP A – (SHAPED WHEELS)  
MAXIMUM OPERATING SPEEDS (RPM) FOR 1/4" MANDRELS  
Overhang – Dimension O  
Shape  
No.  
1”  
1 1/2"  
2”  
2 1/2"  
3”  
A 1  
A 2  
3/4  
1
2 1/2  
1 1/4  
2 3/4  
1 1/4  
1 1/8  
1 1/8  
2
19,800  
38,200  
16,100  
30,560  
45,000  
39,000  
19,860  
48,000  
33,950  
55,560  
72,750  
34,500  
50,930  
39,370  
76,500  
35,620  
61,120  
27,780  
38,200  
38,200  
25,470  
38,200  
23,520  
30,560  
34,500  
47,250  
16,500  
32,620  
13,080  
24,750  
33,750  
29,700  
15,100  
35,250  
32,250  
40,500  
47,620  
26,250  
40,500  
30,370  
49,500  
27,370  
46,500  
26,250  
38,200  
38,200  
25,470  
38,200  
23,520  
30,560  
26,250  
35,250  
13,120  
25,500  
10,730  
20,250  
27,000  
24,000  
12,000  
27,370  
25,500  
30,750  
34,500  
21,000  
30,750  
24,370  
36,370  
22,120  
35,250  
21,000  
30,000  
30,000  
25,470  
31,500  
23,520  
30,560  
21,000  
27,750  
10,650  
20,620  
8,720  
9,000  
16,870  
6,710  
6,750  
13,500  
4,700  
A 3  
1
A 4  
1 1/4  
3/4  
3/4  
7/8  
11/16  
1 1/8  
11/16  
1/4  
1
16,120  
21,000  
18,970  
9,810  
13,120  
16,500  
15,000  
8,220  
10,500  
13,500  
12,000  
7,020  
A 5  
A 6  
A 11  
A 12  
A 13  
A 14  
A 15  
A 21  
A 22  
A 23  
A 24  
A 25  
A 26  
A 31  
A 32  
A 33  
A 34  
A 35  
A 36  
A 37  
A 38  
A 39  
1 1/4  
1 1/8  
7/8  
1 1/16  
1
21,750  
20,620  
24,370  
26,250  
17,250  
24,370  
19,500  
27,000  
18,000  
27,750  
17,250  
24,000  
24,000  
21,970  
25,500  
21,750  
28,100  
17,020  
22,120  
17,250  
16,500  
19,500  
19,870  
13,870  
19,500  
15,000  
20,250  
14,250  
21,370  
13,500  
18,900  
18,900  
18,000  
20,250  
17,620  
22,500  
13,500  
17,250  
13,500  
12,750  
15,000  
13,870  
10,870  
15,000  
12,000  
15,370  
11,250  
15,750  
10,870  
15,000  
15,000  
13,870  
15,900  
13,870  
18,000  
10,650  
13,120  
3/4  
3/4  
1/4  
1
5/8  
1
3/4  
1
5/8  
1 3/8  
1
5/8  
1
5/8  
1/2  
3/8  
3/8  
3/8  
1/4  
1
1
1 1/2  
1
1 5/8  
1 1/4  
1
3/4  
3/4  
History: 1990 AACS.  
Page 55  
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