LAW
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Ohio Laws and Rules
(A) Reserved.
(B) Reserved.
(C) Responsibility.
(1) The employer shall verbally and through demonstration instruct the employee in the safe operation and maintenance of abrasive grinding and cutting and polishing equipment.
(2) It shall be the duty of the employee to operate such equipment in accordance with such instruction.
(D) Abrasive wheel machinery.
(1) General requirements.
(a) Machine guarding.
Abrasive wheels shall be used only on machines provided with safety guards as defined in the following paragraphs of this rule, except:
(i) Wheels used for internal work while within the work being ground;
(ii) Mounted wheels, used in portable operations, two inches and smaller in diameter; and
(iii) Types 16, 17 and 18R and 19 cones, plugs, and threaded hole pot balls where the work offers protection (see appendix to this rule.)
(b) Guard design.
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, except:
(i) Safety guards on all operations where the work provides protection to the operator, may be so constructed 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; and
(ii) The spindle end, nut and outer flange may be exposed on machines, designed as portable saws, when used with abrasive wheels.
(c) Flanges.
Grinding machines shall be equipped with flanges in accordance with paragraph (D)(3) of this rule.
(d) Work rests.
(i) On off-hand grinding machines (see appendix to this rule) 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 to a maximum opening of one-eighth inch to prevent the work from being jammed between the wheel and the rest. The employer shall instruct the employee to securely clamp the work rest after each adjustment. The employer shall also instruct the employee not to adjust the work rest with the wheel in motion.
(ii) The work rest shall be used to support the work wherever practicable.
(iii) Wherever the nature of the work requires contact with the wheel below the horizontal plane of the spindle, work rests need not be used.
(e) Excluded machinery.
Natural sandstone wheels and metal, wooden, cloth, or paper discs, having a layer of abrasive on the surface are not covered by paragraph (D) of this rule.
(2) Guarding of abrasive wheel machinery.
(a) Cup wheels.
Cup wheels types 6 and 11 (see appendix to this rule) shall be protected by:
(i) Safety guards as specified in paragraph (D)(2)(a)(i) of this rule, applies to paragraphs (D)(2)(a) to (D)(2)(j) of this rule;
(ii) Band type guards as specified in paragraph (D)(2)(k) of this rule; and
(iii) Special “revolving cup guards” which mount behind the wheel and turn with it. They shall be made of steel or other material with strength enough to withstand the shock of the bursting wheel and shall enclose the wheel sides upward from the back for one-third of the wheel thickness. The mounting features shall conform with all requirements of paragraph (D) of this rule. It is necessary to maintain clearance between the wheel side and the guard. This clearance shall not exceed one-sixteenth inch.
(b) Guard exposure angles.
The maximum exposure angles specified in paragraphs (D)(2)(a) to (D)(2)(h) of this rule shall not be exceeded. Visors or other necessary equipment shall not be included as a part of the guard when measuring the guard opening, unless such equipment has strength equal to that of the guard.
(c) Bench and floor stands.
(i) The angular exposure of the grinding wheel periphery and sides for safety guards used on machines known as bench and floor stands shall not exceed ninety degrees or one-fourth of the periphery. This exposure shall begin at a point not more than sixty-five degrees above the horizontal plane of the wheel spindle (see figures 12-1 and 12-2 to this rule, and paragraph (D)(2)(i) of this rule).
Figure: Figures 12-1 and 12-2
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(ii) Where the nature of the work requires contact with the wheel below the horizontal plane of the spindle, the exposure shall not exceed one hundred twenty-five degrees (see figures 12-3 and 12-4 to this rule).
Figure: Figures 12-3 and 12-4
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(d) Cylindrical grinders.
The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on cylindrical grinding machines shall not exceed one hundred eighty degrees. This exposure shall begin at a point not more than sixty-five degrees above the horizontal plane of the wheel spindle (see figures 12-5 and 12-6 to this rule, and paragraph (D)(2)(i) of this rule).
Figures 12-5 and 12-6
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(e) Surface grinders and cutting-off machines.
The maximum angular exposure of the grinding 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 one hundred fifty degrees. This exposure shall begin at a point not less than fifteen degrees below the horizontal plane of the wheel spindle (see figures 12-7 and 12-8 to this rule).
Figures 12-7 and 12-8
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(f) Swing frame grinders.
The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on machines known as swing frame grinding machines shall not exceed one hundred eighty degrees, and the top half of the wheel shall be enclosed at all times (see figures 12-9 and 12-10 to this rule).
Figures 12-9 and 12-10
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(g) Automatic snagging machines.
The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on grinders known as automatic snagging machines shall not exceed one hundred eighty degrees and the top half of the wheel shall be enclosed at all times (see figures 12-9 and 12-10 to this rule).
(h) Top grinding.
Where the work is applied to the wheel above the horizontal centerline, the exposure of the grinding wheel periphery shall not exceed sixty degrees (see figures 12-11 and 12-12 to this rule).
Figures 12-11 and 12-12
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(i) Exposure adjustment.
Safety guards of the type described in paragraphs (D)(2)(c) and (D)(2)(d) of this rule, where the operator stands in front of the opening, shall be constructed so that the peripheral protecting member can be adjusted to the constantly decreasing diameter of the wheel. The maximum angular exposure above the horizontal plane of the wheel spindle as specified in paragraphs (D)(2)(c) and (D)(2)(d) of this rule shall never be exceeded, and the distance between the wheel periphery member at the top shall never exceed one-fourth inch (see figures 12-13, 12-14, 12-15, 12-16, 12-17 and 12-18 to this rule).
Figures 12-13, 12-14, 12-15, 12-16, 12-17 and 12-18
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(j) Material requirements and minimum dimensions.
(i) See figures 12-31 and 12-32 and table 12-J to this rule for minimum basic thickness of peripheral and side members for various types of safety guards and classes of service.
(ii) If operating speed does not exceed eight thousand surface feet per minute cast iron safety guards, malleable iron guards or other guards as described in paragraph (D)(2)(j)(iii) of this rule shall be used.
(iii) Cast steel, or structural steel safety guards as specified in figures 12-31 and 12-32 and table 12-J to this rule shall be used where operating speeds of wheels are faster than eight thousand surface feet per minute up to a maximum of sixteen thousand surface feet per minute.
(iv) For cutting-off wheels sixteen inches diameter and smaller and where speed does not exceed sixteen thousand surface feet per minute, cast iron or malleable iron safety guards as specified in figures 12-31 and 12-32 to this rule, and in table 12-J to this rule shall be used.
(v) For cutting-off wheels larger than sixteen inches diameter and where speed does not exceed fourteen thousand two hundred surface feet per minute, safety guards as specified in figures 12-22 and 12-23 to this rule and in table 12-A to this rule shall be used.
(vi) For thread grinding wheels not exceeding one inch in thickness cast iron or malleable iron safety guards as specified in figures 12-31 and 12-32 to this rule and in table 12-J to this rule shall be used.
(k) Band type guards – specifications.
Band type guards shall conform to the following specifications:
(i) The bands shall be of steel plate or other material of equal or greater strength. They shall be continuous, the ends being either riveted, bolted, or welded together in such a manner as to leave the inside free from projections.
(ii) The inside diameter of the band shall not be more than one inch larger than the outside diameter of the wheel, and shall be mounted as nearly concentric with the wheel as practicable.
(iii) 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 that indicated in figure 12-24 and table 12-B to this rule or the wall thickness (W), whichever is smaller.
(3) Flanges.
(a) General requirements.
(i) All abrasive wheels shall be mounted between flanges which shall not be less than one-third the diameter of the wheel.
(ii) 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;
(g) Internal wheels, less than two inches in diameter;
(h) Modified types 6 and 11 wheels (terrazzo);
(i) Cutting-off wheels, types 1 and 27A (see paragraphs (D)(3)(a)(ii)(i)(i) and (D)(3)(a)(ii)(i)(ii) of this rule);
(i) 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;
(ii) 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 figure 12-19 to this rule for one such type of mounting);
(iii) There are three general types of flanges: straight relieved flanges (see figure 12-27 to this rule); straight unrelieved flanges (see figure 12-25 to this rule); and adaptor flanges (see figures 12-28 and 12-29 to this rule);
(iv) Regardless of flange type used, the wheel shall be used in accordance with paragraph (D)(3)(f) of this rule.
Figure 12-19
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(b) Design and material.
(i) Flanges shall be of such design as to satisfactorily transmit the driving torque from the spindle to the grinding wheel.
(ii) Flanges shall be made of steel, cast iron, or other material of equal or greater strength and rigidity.
(iii) Flanges shall be designed with respect to rigidity so that when tightened, the radial width of bearing surface of contact on wheel is maintained (see table 12-F and figure 12-27 to this rule).
(c) Finish and balance.
Flanges shall be dimensionally accurate and in good balance. There shall be no rough surfaces or sharp edges.
(d) Uniformity of diameter.
(i) Both flanges, of any type, between which a wheel is mounted, shall be of the same diameter and have equal bearing surface. Exceptions are set forth in the remaining requirements of this rule.
(ii) 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 interference in side grinding and serves to drive the wheel by its clamping force against the depressed portion of the back flange. The variance in flange diameters, the adaptor nut being less than one-third wheel diameter, and the 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 figure 12-19a to this rule).
Figure 12-19A
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(iii) Modified types 6 and 11 wheels (terrazzo) with tapered K dimension.
(e) Recess and undercut.
(i) Straight relieved flanges made according to table 12-F to this rule and figure 12-27 to this rule shall be recessed at least one-sixteenth inch on the side next to the wheel for a distance as specified in table 12-F to this rule.
(ii) Straight flanges of the adaptor or sleeve type (see table 12-G to this rule and figures 12-28 and 12-29 to this rule) shall be undercut so that there will be no bearing on the sides of the wheel within one-eighth inch of the arbor hole.
(f) Blotters.
(i) Blotters (compressible washers) shall always be used between flanges and abrasive wheel surfaces to ensure uniform distribution of flange pressure (see paragraph (D)(4) of this rule).
(ii) Exceptions.
(a) Mounted wheels;
(b) Abrasive discs (insterted washer, and projecting stud type);
(c) Plate mounted wheels;
(d) Cylinders, cups, or segmental wheels that are mounted in chucks;
(e) Types 27 and 28 wheels;
(f) Type 1 and type 27A cutting-off wheels;
(g) Internal wheels less than two inches in diameter;
(h) Diamond and cubic boron nitride wheels; and
(i) Modified types 6 and 11 wheel (terrazzo) – blotters applied flat side of wheel only.
(g) Multiple wheel mounting.
The driving flange shall be securely fastened to the spindle and the bearing surface shall run true. When more than one wheel is mounted between 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.
(h) Dimensions.
(i) Tables 12-D and 12-F to this rule and figures 12-25 and 12-27 to this rule show minimum dimensions for straight relieved and unrelieved flanges for use with wheels with small holes that fit directly on the machine spindle. Dimensions of such flanges shall never be less than indicated and should be greater where practicable.
(ii) Tables 12-F and 12-G to this rule and figures 12-26 and 12-29 to this rule show 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 indicated and should be greater where practicable.
(iii) Table 12-H to this rule and figure 12-30 to this rule show 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 indicated and should be greater where practicable.
(i) Repairs and maintenance.
All flanges shall be maintained in good condition. When bearing surfaces become worn, warped, sprung, or damaged they shall be trued, refaced, or replaced. When refacing or truing, care shall be exercised to make sure that proper relief and rigidity is maintained as specified in paragraphs (D)(3)(b) and (D)(3)(e) of this rule, and they shall be replaced when they do not conform to these requirements and table 12-D to this rule, figure 12-25 to this rule, table 12-E to this rule, figure 12-26 to this rule, table 12-F to this rule, figure 12-27 to this rule, and table 12-H to this rule, figure 12-30 to this rule. Failure to observe these requirements might cause excessive flange pressure around the hole of the wheel. This is especially true of wheel-sleeve or adaptor flanges.
(4) Mounting.
(a) Inspection.
Immediately before mounting, all wheels shall be closely inspected and sounded by the employer or a designated employee (ring test) 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. Wheels shall be tapped gently with a light nonmetallic implement, such as the handle of a screwdriver 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.”
(i) Wheels must 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 silicate wheels.
(ii) “Tap” wheels about forty-five degrees each side of the vertical centerline and about one or two inches from the periphery as indicated by the spots in figure 12-20 and figure 12-21 to this rule. Then rotate the wheel forty-five degrees and repeat the test. A sound and undamaged wheel will give a clear metallic tone. If cracked, there will be a dead sound and not a clear ring.
Figures 12-20 and 12-21
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(b) 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 pressure from mounting and spindle expansion. To accomplish this, the machine spindle shall be made from a nominal (standard) size to plus.002 inch. A wheel which must be forced on a spindle shall not be used.
(c) Surface condition.
All contact surfaces of wheels, blotters and flanges shall be flat and free of foreign matter.
(d) Bushing.
When a bushing is used in the wheel hole it shall not exceed the width of the wheel and shall not contact the flanges.
(e) Blotters.
A blotter shall be used between the flange and the abrasive wheel. The blotter shall cover the entire contact area of the flange. Blotters need not be used with the following types of wheels:
(i) Mounted wheels;
(ii) Abrasive discs (inserted nut, inserted washer, and projecting stud type);
(iii) Plate mounted wheels;
(iv) Cylinders, cups, or segmented wheels that are mounted in chucks;
(v) Types 27 and 28 wheels;
(vi) Type 1 and type 27A cutting-off wheels;
(vii) Internal wheels less than two inches in diameter; and
(viii) Diamond and cubic boron nitride wheels.
Figures 12-22 and 12-23 Table 12-A
Figure 12-24 Table 12-B
Figure 12-25
Figure 12-26 Table 12-E
Figure 12-27
Figures 12-28 and 12-29 Table 12-G
Figure 12-30 (no link provided)
Figure: Figures 12-31 and 12-32 Table 12-J
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Table 12-J, Minimum Basic Thickness of Peripheral and Side Members for Safety Guards * 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.
Appendix TO RULE 4121:1-5-12
5.12.1 – TYPE 1 STRAIGHT WHEELS
Definition: Type 1 straight wheels have diameter, thickness and hole size dimensions and should be used only on the periphery. Type 1 wheels shall be mounted between flanges.
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 maximum hole size of not more than one-quarter of the wheel diameter.
Figure: Type 1 – Straight Wheel
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5.12.2 – TYPE 2 CYLINDER WHEELS
Definition: Type 2 cylinder wheels have diameter, wheel thickness and rim thickness dimensions. Grinding is performed on the rim face only, dimension 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.
Figure: Type 2 – Cylinder Wheel
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5.12.3 – ABRASIVE DISC WHEELS
Definition: Abrasive discs have diameter, thickness and hole size dimensions. They are used in a manner similar to Type 2 cylinder wheels.
Limitation: Wheel thickness, T dimension, must be less than rim thickness, W dimension.
Figure: Abrasive Disc Wheels
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5.12.4 – 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.
Limitation: Grinding face, thickness dimension U, must be equal to or greater than one-half T dimension. J dimension shall be large enough to accommodate suitable flanges. If tapered safety flanges are used, J dimension and degree of taper required shall be determined by the wheel manufacturer.
Figure: Type 4 – Taper Sided Wheel
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5.12.5 – TYPE 5 RECESSED ONE SIDE WHEELS
Definition: Type 5 recessed one side wheels have diameter, thickness and hole size dimensions and in addition 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.
Limitation: Type 5 wheels are subject to the same limitation of hole size as Type 1 wheels definition 5.12.1.
In addition, recess depth, F dimension, should not exceed 50% of wheel thickness, T dimension, and diameter of recess, P dimension, shall be large enough to accommodate a suitable flange.
Figure: Wheel, recessed one side
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5.12.6 – TYPE 6 STRAIGHT CUP WHEELS
Definition: Type 6 cup wheels have diameter, thickness, hole size, rim thickness and back thickness dimensions. Grinding is always performed on rim face, W dimension.
Limitation: Minimum back thickness, E dimension, should not be less than 1/4 T dimension. In addition, when unthreaded hole wheels are specified, the inside flat, K dimension, must be large enough to accommodate a suitable flange.
Figure: Type 6 – Straight Cup Wheel
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5.12.7 – TYPE 7 DOUBLE RECESSED WHEELS
Definition: Type 7 double recessed wheels have diameter, thickness and hole size dimensions and in addition 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 5.12.2.
Limitation: Type 7 wheels are subject to the same limitation of hole size as Type 1 wheels, section 5.12.1.
In addition, the combined depths of the recess, F and G dimensions, should not exceed 50% of wheel thickness, T dimension.
Figure: Type 7 – Wheel, recessed two sides
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5.12.8 – TYPE 11 FLARING CUP WHEELS
Definition: Type 11 Flaring cup wheels have double diameter 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 5.12.6.
Limitation: Minimum back thickness, E dimension, should not be less than 1/4 T dimension. In addition when unthreaded hole wheels are specified the inside flat, K dimension, shall be large enough to accommodate a suitable flange.
Figure: Type 11 – Flaring Cup Wheel
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5.12.9 – 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 performed on both A and U dimensions.
Limitation: Minimum back thickness, E dimension, should be equal to or greater than 1/2 wheel thickness, T dimension. If unthreaded hole wheels are specified K dimension shall be large enough to accommodate a suitable flange.
Type 12 – Dish Wheel
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5.12.10 – TYPE 13 SAUCER WHEELS
Definition: Type 13 saucer wheels have diameter, thickness, hole size and back thickness dimensions. Grinding shall be performed on wheel periphery, U dimension, only.
Limitation: Where unthreaded hole wheels are specified, J and K dimensions shall be large enough to accommodate suitable flanges. In addition, wheel thickness shall be uniform throughout, U dimension should always equal E dimension.
Type 13 – Saucer Wheel
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5.12.11 – TYPES 16, 17, 18, 18R & 19 CONE & PLUG WHEELS
Definition: Type 16 cones have a curved side with a nose radius Type 17 cones have straight sides with or without a nose radius. Types 18 and 18R plug wheels are cylindrical in shape with either a square or curved grinding end. Type 19 cone wheels are a combination of cone and plug type shapes and are usually specified where base dimension D in a Type 17 cone would not provide an adequate cross section of abrasive. All types of cone and plug wheels are manufactured 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 spindle so that surface D seats firmly against an unrelieved, flat back-up flange. It is recommended that the maximum size or mass of the above cones and plugs be not greater than that of a 3” diameter by 5” long Type 18 plug wheel.
Type 16 – Cone, curved side
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Types 17, 18, 18R and 19 – Cone and Plug Wheels
5.12.12 – TYPES 20, 21, 22, 23, 24, 25, 26 RELIEVED AND/OR RECESSED WHEELS
Definition: Types 20 through 26 relieved and/or recessed wheels have diameter, thickness, hole size, recess diameter and depth dimensions and in addition may be concaved on one or both sides. Types 20 through 26 wheels are subject to the same limitations of use and mounting as Type 5 wheels, definition 5.12.5.
Limitation: Concaved relief depths shall be considered as recesses and added to straight recess depth or depths for determination of total wheel recess depth. Total recess depths should not exceed 50% of wheel thickness, T dimension.
Types 20 and 21 – Relieved wheels
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Types 22, 23, 24, 25 and 26 – Relieved and recessed wheels
5.12.13 – 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 interference with the mounting. Type 27 wheels are manufactured with flat grinding rims permitting 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 mounting of these types of wheels.
Types 27 and 28 – Wheels, depressed center
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5.12.14 – TYPE 27A DEPRESSED CENTER WHEELS
Definition: Type 27A depressed center, cutting-off wheels have diameter, thickness and hole size dimensions. They are reinforced, organic bonded, off-set hub type wheels, usually 16” diameter and larger, specially designed for use on cutting-off machines where mounting nut or outer flange interference cannot be tolerated.
Limitation: See illustration for mounting details.
Type 27A wheel, mounting details
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5.12.15 – 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 5.12.1. 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 Maximum Thickness ______________ _________________ 6” and smaller 3/16” Larger than 6” to 12” 1/4” Larger than 12” to 23” 3/8” Larger than 23” 1/2”
Maximum hole size for cutting-off wheels should not be larger than 1/4 wheel diameter.
For Figure – To obtain the appendix, table, image, etc. please call LSC’s ERF Helpdesk at 614-387-2078 or send an email to erfhelpdesk@lsc.state.oh.us.
Wet machine with horizontal movement for slabbing
5.12.16 – COPING WHEELS
Definition: Coping wheels are peripheral cutting wheels, and have diameter, thickness and hole size dimensions. They may be metal or organic bonded, solid or steel centered, and are subject to the same limitations of use and mounting as Type 1 wheels, definition 5.12.1.
Limitation: Coping wheels are recommended for use only on specially designed and fully guarded machines.
Slotting a block of marble to contour using a coping wheel
For Figure – To obtain the appendix, table, image, etc. please call LSC’s ERF Helpdesk at 614-387-2078 or send an email to erfhelpdesk@lsc.state.oh.us.
5.12.17 – TUCK POINTING WHEELS
Definition: Tuck pointing wheels, usually Type 1, reinforced 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 5.12.1.
Limitation: Wheels used for tuck pointing should be reinforced, organic bonded.
Tuck pointing granite using a straight resinoid reinforced wheel
For Figure – To obtain the appendix, table, image, etc. please call LSC’s ERF Helpdesk at 614-387-2078 or send an email to erfhelpdesk@lsc.state.oh.us.
5.12.18 – MOUNTED WHEELS
Definition: Mounted wheels, usually 2” diameter or smaller, and of various shapes, may be either organic or inorganic bonded abrasive wheels. They are secured to plain or threaded steel mandrels.
Grinding wheels known as mounted wheels
For Figure – To obtain the appendix, table, image, etc. please call LSC’s ERF Helpdesk at 614-387-2078 or send an email to erfhelpdesk@lsc.state.oh.us.
5.12.19 – THREADED HOLE CUP WHEELS
Definition: 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 anchored 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.
Cup wheels
For Figure – To obtain the appendix, table, image, etc. please call LSC’s ERF Helpdesk at 614-387-2078 or send an email to erfhelpdesk@lsc.state.oh.us.
5.12.20 – MODIFIED TYPES 6 & 11 WHEELS (TERRAZZO)
Definition: Some Type 6 and 11 cup wheels used in the terrazzo 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 special tapered flange.
Modified Types 6 and 11 wheels (terrazzo)
For Figure – To obtain the appendix, table, image, etc. please call LSC’s ERF Helpdesk at 614-387-2078 or send an email to erfhelpdesk@lsc.state.oh.us.
(E) Wire buffing wheels.
Wire buffing wheels shall be guarded unless the nature of the work is such that the material being processed acts as a shield to the periphery of the wheel, such as internal buffing.
(F) Polishing equipment.
(1) When dry grinding, dry polishing, or buffing is being performed, suitable hoods, or enclosures, connected to exhaust systems shall be used.
(2) Such exhaust systems shall be operated continuously whenever such operations are being done and shall be capable of preventing contaminants from entering the breathing zone.
HISTORY: Eff 4-1-64; 8-1-77; 1-1-86
Rule promulgated under: RC Chapter 119.
Rule authorized by: RC 4121.13
Rule created by: Const. Art. II Sec. 35
119.032 Review Date: 3-1-03