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(continued)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3555. Definitions.
Jack. A jack is an appliance for lifting and lowering or moving horizontally a load by application of a pushing force.
Note: Jacks may be of the following types: Lever and ratchet, screw and hydraulic.
Rating. The rating of a jack is the maximum working load for which it is designed to lift safely that load throughout its specified amount of travel.
Note: To raise the rated load of a jack, the point of application of the load, the applied force, and the length of lever arm should be those designated by the manufacturer for the particular jack considered.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3556. General.
(a) Each employer shall be responsible for the safe condition of tools and equipment used by employees, including tools and equipment which may be furnished by employees.
(b) All tools shall be restricted to the use for which they are intended.
(c) Unsafe hand tools shall not be used.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3557. Switches and Controls for Portable Tools.
(a) All hand-held powered circular saws having a blade diameter greater than 2 inches, electric, hydraulic or pneumatic chain saws, and percussion tools without positive accessory holding means shall be equipped with a constant pressure switch or control that will shut off the power when the pressure is released. All hand-held gasoline powered chain saws shall be equipped with a constant pressure throttle control that will shut off the power to the saw chain when the pressure is released.
(b) All hand-held powered drills, tappers, fastener drivers, horizontal, vertical, and angle grinders with wheels greater than 2 inches in diameter, disc sanders with discs greater than 2 inches in diameter, belt sanders, reciprocating saws, saber, scroll, and jig saws with blade shanks greater than a nominal one-fourth inch, and other similarly operating powered tools shall be equipped with a constant pressure switch or control, and may have a lock-on control provided that turnoff can be accomplished by a single motion of the same finger or fingers that turn it on.
(c) All other hand-held powered tools, such as, but not limited to, platen sanders, grinders with wheels 2 inches in diameter or less, disc sanders with discs 2 inches in diameter or less, routers, planers, laminate trimmers, nibblers, shears, saber, scroll, and jig saws with blade shanks a nominal one-fourth of an inch wide or less, may be equipped with either a positive "on-off" control, or other controls as described in this section.
Note: "Nominal" in (b) and (c) means +- 0.05 inch.
(d) The operating control on hand-held power tools shall be so located as to minimize the possibility of its accidental operation, if such accidental operation would constitute a hazard to employees.
Exception: This section does not apply to concrete vibrators, concrete breakers, powered tampers, jack hammers, rock drills, garden appliances, household and kitchen appliances, personal care appliances, medical or dental equipment, or to fixed machinery.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3558. Portable Power Driven Circular Saws (Class A).
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3559. Pneumatic and Powder-Actuated Tools.
(a) Safety clips or retainers shall be installed on pneumatic impact tools to prevent dies and tools from being accidentally expelled from the barrel, or other effective means to prevent accidents from this source shall be used.
(b) Powder-actuated tools used in industrial operations shall be designed, constructed, operated and maintained in compliance with Article 27 of the Construction Safety Orders.
(c) All hand-held pneumatically powered tools used for driving nails, staples and similar fasteners which operate at 100 psig or more line pressure shall have a safety device at the muzzle to prevent the tool from discharging until the muzzle is in contact with a solid surface.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3559.1. Airless Spray Guns.
(a) Airless spray guns of the type which atomize paints and fluids at high pressures (1,000 pounds or more per square inch) shall be equipped with automatic or visible manual safety devices which will prevent pulling of the trigger to prevent release of the paint or fluid until the safety device is manually released.
(b) In lieu of (a) above, a diffuser nut which will prevent high pressure, high velocity release, while the nozzle tip is removed, plus a nozzle tip guard which will prevent the tip from coming into contact with the operator, or other equivalent protection, shall beprovided.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3560. Portable Grinders.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3561. Portable Sanders.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3562. Jacks.
(a) The rated load shall be legibly and permanently marked on a prominent location on the jack by casting, stamping, or other suitable means.
(b) All jacks shall be designed so that their maximum safe extension cannot be exceeded.
(c) Hydraulic jacks exposed to freezing temperatures shall be supplied with an adequate antifreeze liquid.
(d) In the absence of a firm foundation, the base of the jack shall be blocked. If there is a possibility of slippage of the cap, a block shall be placed in between the cap and the load.
(e) Employees shall not be permitted to enter the zone beneath a jack supported load unless it has been effectively blocked or cribbed.
(f) All jacks requiring periodic cleaning and lubrication, such as screw jacks, shall be properly cleaned and lubricated at regularintervals.
Note: Authority cited: Section 142.3, Labor Code. Reference Section 142.3, Labor Code.
s 3563. Power Lawn Mowers.
(a) Scope. These regulations apply to power lawn mowers of 20-brake horsepower or less and cover walk-behind reel and rotary power lawn mowers, riding reel and rotary power lawn mowers, lawn riding tractors, and lawn and garden riding tractors, and related mower attachments. They are intended to provide safety requirements and to help ensure uniform operator environments. These regulations do not apply to sulky-type units, flail mowers, or sickle bar mowers.
Note: For tractors of more than 20-brake horsepower see Article 25.
(b) General.
(1) Power mowers placed in service after March 29, 1975 through April 15, 1999, shall be designed, constructed, tested and labeled to meet the provisions of ANSI B71.1-1972 and B71.1a-1974 or ANSI B71.1-1980, Safety Specifications for Power Lawn Mowers, Lawn and Garden Tractors and Lawn Tractors.
(2) Power mowers placed in service after April 15, 1999 shall be approved as defined in Section 3206 of the General Industry Safety Orders.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3564. Portable Winches.
(a) Portable winches shall be secured against accidental shifting while in use.
(b) Portable winches shall be fitted with limit switches if employees have access to areas from which it is possible to be drawn into the winch.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3575. Scope and Definitions.
(a)(1) Scope. This Article establishes safety requirements for the use, care, and protection of abrasive wheels, safety guards, flanges, chucks, proper storage, handling and mounting. This Article does not apply to natural sandstone, pulpstone, coated abrasive products and surface conditioning wheels used for polishing, buffing, cleaning, finishing, blending or light deburring, where the base material is not removed.
(2) Abrasive wheels manufactured on or before July 1, 1998 shall meet the requirements of either ANSI B7.1-1978 or ANSI B7.1-1988, Safety Requirements for the Use, Care, and Protection of Abrasive Wheels. Abrasive wheels manufactured after July 1, 1998 shall be labeled as meeting the requirements of ANSI B7.1-1988, Safety Requirements for the Use, Care and Protection of Abrasive Wheels.
(b) Definitions.
Abrasive Wheels. Power-driven wheels consisting of abrasive particles held together by inorganic or organic bonds. Metal, wooden, cloth or paper wheels or discs having a layer or layers of abrasive on the surface and natural sandstones (quarried) are not included.
(A) Cutting Off Wheels. Wheels having diameter thickness and hole size dimensions and are subject to all limitations of mounting and use listed for type 1 wheels. They may be steel centered, diamond abrasive or organic bonded abrasive of the plain or reinforced type.
1. 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.
Max.
thickness
Wheel diameter: (inch)
6 inch and smaller.................... 3/16
Larger than 6 inches to 12 inches..... 1/4
Larger than 12 inches to 23 inches.... 3/8
Larger than 23 inches................. 1/2
2. Maximum hole size for cutting-off wheels should not be larger than 1/4-wheel diameter.
(B) Cylinder Wheels. Wheels having 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.
Limitation: Rim height, T dimension, is generally equal to or greater than rim thickness, W dimension.
(C) Depressed Center Wheels. Have diameter, thickness and hole size dimensions. Both types are reinforced, organic bonded wheels having offset 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.
1. Special supporting, back adapter and inside flange nuts are required for the proper mounting of these types of wheels.
2. Mounts which are affixed to the wheel by the manufacturer may not require an inside nut and shall not be reused.
(D) Depressed Center. Cutting-off Wheels, Type 27A. Wheels having diameter, thickness, and hole size dimensions. They are reinforced, organic bonded, offset hub type wheels, usually 16 inches diameter and larger, specially designed for use on cutting-off machines where mounting nut or outer flange interference cannot be tolerated.
(E) Flaring Cup Wheels. Wheels having 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.
Limitation: Minimum back thickness, E dimension, should not be less than one-fourth T dimension. In addition when unthreaded hole wheels are specified the inside flat, K dimension, shall be large enough to accommodate a suitable flange.
(F) Inorganic Wheels. Wheels which are bonded by means of inorganic material such as clay, glass, porcelain, sodium silicate, magnesium oxychloride, or metal. Wheels bonded with clay, glass, porcelain or related ceramic materials are characterized as "vitrified bonded wheels."
(G) Mandrel A steel shaft usually 3/8-inch diameter or smaller which is permanently secured to the abrasive section by cementing or other means. It is mounted in the machine and is the means by which the power is transmitted from the machine to the abrasive.
(H) Modified Types 6 and 11 Wheels (terrazzo). Some type 6 and 11 cup wheels used in the terrazzo trade having 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.
(I) Mounted Wheels. Wheels which are usually 2 inches diameter or smaller, and of various shapes, and are permanently secured to a steel mandrel.
(J) Organic Wheels. Wheels which are bonded by means of an organic material such as resin, rubber, shellac, or other similar bonding agent.
(K) Straight Wheels. Wheels having diameter, thickness, and hole size dimensions, and they 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.
(L) Straight Cup Wheels. Wheels having diameter, thickness, hole size, rim thickness, and back thickness dimensions. Grinding is always performed on rim face, W dimension.
Limitation: Minimum back thickness, = dimension, should not be less than one-fourth T dimension. In addition, when unthreaded hole wheels are specified, the inside flat, K dimension, must be large enough to accommodate a suitable flange.
Type 6 -Straight-cup Wheel Side grinding wheel having a diameter,thickness and
hole with one side straight or flat and the opposite is derecessed. This type,
however, differs from Type 5 in that the grinding is performed on the wall of
the abrasive created by the difference between the diameter of the recess and
the outside diameter of the wheel. Therefore, the wall dimension "W" takes
precedence over the diameter of the recess as an essential intermediate
dimension to describe this shape type.
Flanges. Collars, discs or plates between which wheels are mounted and are referred to as adaptor, sleeve, or back up type. See Section 3579.
Off-hand Grinding. The grinding of any material or part which is held in the operator's hand.
Portable Grinding. A grinding operation where the grinding machine is designed to be hand held and may be easily moved from one location to another.
Protection Hood. A protection hood is an enclosure for an abrasive wheel consisting of a peripheral and two side members. Its main function is to effectively retain the pieces of the wheel should the wheel break in operation.
Reinforced Wheels. A class of organic wheels which contain strengthening fabric or filament. The term "reinforced" does not cover wheels using such mechanical additions as steel rings, steel cup backs or wire or tape winding.
Safety Guard. An enclosure designed to restrain the pieces of the abrasive wheel in the event that the wheel is broken while in operation.
Snagging. Grinding which removes relatively large amounts of material without regard to close tolerances or surface finish requirements.
Surface Feet per Minute (s.f.p.m.). The distance in feet any one abrasive grain on the peripheral surface on a grinding wheel travels in 1 minute.
Surface Feet Per Minute = _____ 3.1416 _____x_____ diameter in inches _____ x_____ r.p.m.
12 or .262 x diameter in inches x r.p.m.
Tuck Pointing. Removal of cement, mortar, or other non-metallic jointing material from masonry mortar joints and pointing up the tuck or joint.
Tuck Pointing Wheels. 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.
Note: Wheels used for tuck pointing should be reinforced, organic bonded.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3576. General Machine Requirements.
(a) Stationary grinding machines shall be sufficiently heavy and rigid so as to prevent dangerous vibration and shall be securely mounted on substantial floors, benches, foundations or other adequate and safe structures.
(b) Portable grinders shall not be used as bench grinders unless they are securely clamped in place, having ample clearance between the wheels and the bench, and are equipped with standard wheel and arbor end guards and tool rests. "C" clamps shall not be used to secure grinders to benches. Special band clamps or other equivalent means shall be used which encircle the machine and are secured by means of bolts.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3577. Protection Devices.
(a) Abrasive wheel machinery guards shall meet the design specifications of the American National Standard Safety Requirements for the Use, Care, and Protection of Abrasive Wheels, ANSI B 7.1-1978. This requirement shall not apply to natural sandstone wheels or metal, wooden, cloth, or paper discs having a layer of abrasive on the surface.
(b) Abrasive wheels shall be provided with protection hoods or safety guards which shall be of such design and construction as to effectively protect the employee from flying fragments of a bursting wheel insofar as the operation will permit.
Exceptions: This requirement does not apply to the following classes of wheels and conditions. 1. Wheels used for internal work while within the work being ground. 2. Special precision tool room grinders under the supervision of expert mechanics. 3. Type 1 wheels not larger than 2 inches in diameter and not more than 1/2-inch thick, operating at peripheral speeds less than 1800 SFPM when mounted on mandrels driven by portable drills. 4. Type 1 Reinforced wheels not more than 3 inches in diameter and 1/4-inch in thickness, operating at peripheral speeds not exceeding 9,500 SFPM, provided that safety glasses and face shield protection are worn. 5. Types 16, 17, 18, 18R and 19 cones and plugs and threaded hole pot balls where the work offers protection or where the size does not exceed 3 inches in diameter by 5 inches long. 6. Metal centered diamond lapidary wheels either notched, segmented or continuous rim used with a coolant deflector, when operated at speeds up to 3,500 SFPM. 7. Mounted wheels 2 inches and smaller in diameter used in portable operations. 8. Valve seat grinding wheels.
(c) The hood 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.
Exceptions: 1. Protection hoods on cylindrical grinding machines, in all operations where the work provides a suitable measure of protection to the operator, may be so constructed that the spindle end, nut, and flanges 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. 2. The spindle end, nut, and outer flange may be exposed on machines designed as portable saws.
(d) Cup wheels shall be protected by:
(1) Band type guards of such design and construction as to effectively protect the employee.
(2) Special "Revolving Cup Guards" which mount behind the wheel and turn with it. They shall be made of steel or other material of adequate strength 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 this section. It is necessary to maintain clearance between the wheel side and the guard. This clearance shall not exceed one-sixteenth inch.
(See Figures A-26, A-27, A-28 of Appendix G.)
(e) Work rests. On offhand grinding machines, work rests shall be used to support the work. They shall be of rigid construction and designed to be adjustable to compensate for wheel wear. Work rests shall be kept adjusted closely to the wheel with a maximum opening of one-eighth inch. The work rest shall be secured after each adjustment. The adjustment shall not be made with the wheel in motion.
Exceptions: 1. Where the shape of the work will not permit their use. 2. Where the size of the material is such that it cannot wedge between the guard and the wheel.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3578. Permissible Wheel Exposure for Periphery Grinding.
(a) Bench and Floor Stands. The angular exposure of the grinding wheel periphery and sides for safety guards used on machines known as bench and floor stands should not exceed 90 degrees or one-fourth of the periphery. This exposure shall begin at a point not more than 65 degrees above the horizontal plane of the wheel spindle. (See Figure A-1 of Appendix A.)
Whenever the nature of the work requires contact with the wheel below the horizontal plane of the spindle, the exposure shall not exceed 125 degrees. (See Figure A-2 of Appendix A.)
(b) Cylindrical Grinders. The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on cylindrical grinding machines shall not exceed 180 degrees. This exposure shall begin at a point not more than 65 degrees above the horizontal plane of the wheel spindle. (See Figure A-3 of Appendix A.)
(c) Surface Grinders and Cutting Machines. The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on cutting machines and on surface grinding machines which employ the wheel periphery shall not exceed 150 degrees. This exposure shall begin at a point not less than 15 degrees below the horizontal plane of the wheel spindle. (See Figure A-4 of Appendix A.)
(d) Swing Frame and Automatic Snagging Machines. The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on machines known as swing frame and automatic snagging machines shall not exceed 180 degrees, and the top half of the wheel shall be protected at all times. (See Figure A-5 of Appendix A.)
(e) Top Grinding. In operations where the work is ground on the top of the wheel, the exposure of the grinding wheel periphery shall be as small as practical, with a maximum exposure of 60 degrees. (See Figure A-6 of Appendix A.)
(f) Guard Exposure Angles. The maximum exposure angles specified above shall not be exceeded. Visors or other accessory 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.
(g) Exposure Adjustment. Guards of the types described in subsections (a) and (b) of this section 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 subsections (a) and (b) of this section shall never be exceeded, and the distance between the wheel periphery and the adjustable tongue or the end of the peripheral member at the top shall never exceed one-fourth inch. (See Figures A-7, 8, 9, 10, 11, and 12 of Appendix B.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3579. Flanges -General Requirement.
(a) All abrasive wheels shall be mounted between flanges which shall not be less than one-third the diameter of the wheel.
Exceptions: (1) Mounted wheels. (2) Portable wheels with threaded inserts or projecting studs. (3) Abrasive discs (inserted nut, inserted washer and projecting stud type). (4) Plate mounted wheels. (5) Cylinders, cups, or segmental wheels that are mounted in chucks. (6) Types 27 and 28 wheels. (7) Certain internal wheels. (8) Modified Types 6 and 11 wheels (terrazzo). (9) Cutting-off wheels, Types 1 and 27A: (A) 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. (B) 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 A-13 of Appendix C for one such type of mounting.)
Note: There are three general types of flanges:
1. Straight relieved flanges. (See Figure A-16 of Appendix D.)
2. Straight unrelieved flanges. (See Figure A-17 of Appendix D.)
3. Adaptor flanges. (See Figures A-18 and A-19 of Appendix D.)
(b) Regardless of flange type used, the wheel shall always be guarded. Blotters shall be used in accordance with subsection (g) of this section.
(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 Diameters.
Both flanges, of any type, between which a wheel is mounted, shall be of the same diameter and have equal bearing surface.
Exceptions: (1) Type 27 and Type 28 wheels because of their shape and usage, require specially designed adaptors. (2) Modified Types 6 and 11 wheels (terrazzo) with tapered K Dimensions.
(e) 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 A-14 and A-15 of Appendix C.)
(f) Recess and Undercut.
(1) Straight relieved flanges made according to Table A-1 and Figure A-16 shall be recessed at least one-sixteenth inch on the side next to the wheel for a distance as specified in Table A-1.
(2) Straight flanges of the adaptor or sleeve type (Table A-4 and Figures A-18 and A-19) shall be undercut so that there will be no bearing on the sides of the wheel within one-eighth inch of the arbor hole. (Figures A-18 and A-19 are illustrated in Appendix D.)
(g) Blotters. Blotters (compressible washers) shall always be used between flanges and abrasive wheel surfaces to insure uniform distribution of flange pressure. [See Section 3480(e).]
Exceptions: (1) Mounted wheels. (2) Abrasive discs (inserted nut, inserted washer, and projecting stud type). (3) Plate mounted wheels. (4) Cylinders, cups, or segmental wheels that are mounted in chucks. (5) Types 27 and 28 wheels. (6) Certain Type 1 and Type 27A cutting-off wheels. (7) Certain internal wheels. (8) Type 4 tapered wheels. (9) Diamond wheels, except certain vitrified diamond wheels. (10) Modified Types 6 and 11 wheels (terrazzo) - blotters applied flat side of wheel only.
(h) Driving Flange. 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. [See Section 3480(f).]
(i) Dimensions.
(1) Tables A-1 and A-2 and Figures A-16 and A-17 of Appendix D 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.
(2) Tables A-3 and A-4 and Figures A-18 and A-19 of Appendix D 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.
(3) Table A-5 and Figure A-19 of Appendix D 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.
(j) Repairs and maintenance. All flanges shall be maintained in good condition. When the bearing surfaces become worn, warped, sprung, or damaged they should be trued or refaced. When refacing or truing, care shall be exercised to make sure that proper relief and rigidity is maintained as specified in subsection (f) of this section and they shall be replaced when they do not conform to this subsection and Table A-2, Figure A-17, Table A-3, Figure A-18, Table A-1, Figure A-16, and Table A-5, Figure A-19. Failure to observe these rules might cause excessive flange pressure around the hole of the wheel. This is especially true of wheel-sleeve or adaptor flanges. (Figures A-16, A-17, A-18 and A-19 are illustrated in Appendix D.)
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3580. Mounting.
(a) Inspection. Immediately before mounting, all wheels shall be closely inspected and sounded by the user (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 should 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.
Note: This is known as the "Ring Test." 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. "Tap" wheels about 45 degrees each side of the vertical centerline and about 1 or 2 inches from the periphery as indicated by the spots in Figure A-20 and Figure A-21 of Appendix E. Then rotate the wheel 45 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."
(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 to nominal (standard) size plus zero minus .002 inch, and the wheel hole shall be made suitably oversize to assure safety clearance under the conditions of operating heat and pressure.
(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. When blotters or flange facings of compressible material are required, they shall cover entire contact area of wheel flanges. Highly compressible material such as blotting paper as normally used should not exceed.025 inch in thickness. If material of lower compressibility is used, greater thickness may be necessary. Blotters need not be used with the following types of wheels:
(1) Mounted wheels.
(2) Abrasive discs (inserted nut, inserted washer, and projecting-stud type).
(3) Plate mounted wheels.
(4) Cylinders, cups, or segmental wheels that are mounted in chucks.
(5) Types 27 and 28 wheels.
(6) Certain Type 1 and Type 27A cutting-off wheels.
(7) Certain internal wheels.
(8) Type 4 tapered wheels.
(9) Diamond wheels, except certain vitrified diamond wheels.
(f) Multiple wheel mounting. 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. When mounting wheels which have not been cemented together, or ones which do not utilize separating spacers, wheels specially manufactured for that purpose shall be used.
(g) Replacing safety guard. After mounting a wheel, safety guard shall be properly positioned before starting the wheel.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3581. Speed.
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3582. Storage.
Abrasive wheels shall not be stored where they would be subjected to exposure to high temperature or humidity, water or other liquids, freezing temperature or any temperature low enough to cause condensation on the wheels when moved from storage to an area of higher temperature, or where they would be subjected to physical damage from falling tools or materials.
FIGURES A-15 through A-22
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
s 3583. Portable Abrasive Wheels.
(a) General requirements. Abrasive wheels shall be used only on machines provided with safety guards as required in Section 3577(b).
(b) A 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.
Exceptions: (1) Safety guards on all operations where the work provides a suitable measure of protection to the operator may be so constructed that the spindle end, nut and outer flange are exposed. 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. (2) The spindle end, nut, and outer flange may be exposed on portable machines designed for, and used with, Types 6, 11, 27, and 28 abrasive wheels, cutting-off wheels, and tuck pointing wheels.
(c) Cup wheels. Cup wheels (Types 6 and 11) shall be protected by:
(1) Safety guards as specified in this section; or
(2) Special "Revolving Cup Guards" which mount behind the wheel and turn with it. They shall be made of steel or other material with adequate strength and shall enclose the wheel sides upward from the back for one-third of the wheel thickness. The mounting features shall conform with all regulations. (See Section 3580.) It is necessary to maintain clearance between the wheel side and the guard. The clearance shall not exceed one-sixteenth inch; or,
(3) Some other form of guard that will insure as good protection as that which would be provided by the guards specified in subsections (a) and (b) of this section.
(d) Vertical portable grinders. Safety guards used on machines known as right angle head or vertical portable grinders shall have a maximum exposure angle of 180 degrees, and the guard shall be so located so as to be between the operator and the wheel during use. Adjustment of guard shall be such that pieces of an accidentally broken wheel will be deflected away from the operator. (See Figure A-22 of Appendix E.)
(e) Other portable grinders. The maximum angular exposure of the grinding wheel periphery and sides for safety guards used on other portable grinding machines shall not exceed 180 degrees and the top half of the wheel shall be enclosed at all times. (See Figure A-23 of Appendix E.)
(f) Mounting and inspection of abrasive wheels.
(1) Immediately before mounting, all wheels shall be closely inspected and sounded by the user 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.
(2) 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 to nominal (standard) size plus zero minus .002 inch, and the wheel hole shall be made suitably oversize to assure safety clearance under the conditions of operating heat and pressure.
(3) All contact surfaces of wheels, blotters, and flanges shall be flat and free of foreign matter.
(4) When a bushing is used in the wheel hole it shall not exceed the width of the wheel and shall not contact the flanges.
TABLE A-1 MINIMUM DIMENSIONS FOR STRAIGHT RELIEVED FLANGES
----------------------------------------------------------------
A [FNa1] B C D E
Minimum Radial Width of Minimum Minimum
Outside Bearing Surface Thickness Thickness of
------------------------
Diameter Diameter of of Flange Flange at
Edge
of Wheel Flanges Minimum Maximum at Bore of Recess
-------------------------------------------------------------------------------
Inches Inches Inches Inches Inches Inches
1 ......... 3/8 ....... 1/16 ........ 1/8 ........ 1/16 ........ 1/16
2 ......... 3/4 ........ 1/8 ....... 3/16 ........ 1/8 ......... 3/33
3 .......... 1 ......... 1/8 ....... 3/16 ........ 3/16 ........ 3/33
-------------------------------------------------------------------------------
4 ........ 1 1/8 ....... 1/8 ....... 3/16 ........ 3/16 ......... 1/8
5 ........ 1 3/4 ...... 3/16 ........ 1/4 ........ 1/4 .......... 1/8
6 .......... 2 ......... 1/4 ........ 1/2 ........ 3/8 ......... 3/16
7 ........ 2 1/2 ....... 1/4 ........ 1/3 ........ 3/8 ......... 3/16
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8 .......... 3 ......... 1/4 ........ 1/2 ........ 3/8 ......... 3/16
10 ....... 3 1/2 ...... 3/16 ........ 3/8 ........ 3/8 .......... 1/4
12 ......... 4 ........ 3/16 ........ 3/8 ........ 1/3 ......... 3/16
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14 ....... 4 1/2 ....... 3/8 ........ 3/4 ........ 1/2 ......... 3/16
16 ....... 5 1/2 ....... 1/2 ......... 1 ......... 1/2 ......... 3/16
18 ......... 6 ......... 1/2 ......... 1 ......... 3/8 .......... 3/8
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20 ......... 7 ......... 3/8 ....... 1 1/4 ....... 3/8 .......... 3/8
22 ....... 7 1/2 ....... 3/8 ....... 1 1/4 ....... 3/8 ......... 7/16
24 ......... 8 ......... 3/4 ....... 1 1/4 ....... 3/8 ......... 7/16
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26 ....... 8 1/2 ....... 3/4 ....... 1 1/4 ....... 1/8 .......... 1/2
28 ........ 10 ......... 7/8 ....... 1 1/2 ....... 3/4 .......... 1/2
30 ........ 10 ......... 7/8 ....... 1 1/2 ....... 3/4 .......... 3/8
-------------------------------------------------------------------------------
36 ........ 12 .......... 1 .......... 2 ......... 7/8 .......... 3/4
-------------------------------------------------------------------------------
42 ........ 14 .......... 1 .......... 2 ......... 7/8 .......... 3/4
48 ........ 16 ........ 1 1/4 ........ 2 ........ 1 1/8 .......... 1
60 ........ 20 ........ 1 1/4 ........ 2 ........ 1 1/4 ........ 1 1/8
72 ........ 24 ........ 1 1/2 ...... 2 1/2 ...... 1 3/8 ........ 1 1/4
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[FNa1] Flanges for wheels under 2 inches diameter may be unrelieved and shall
be maintained flat and true.
TABLE A-2
MINIMUM DIMENSIONS FOR STRAIGHT UNRELIEVED FLANGES FOR
WHEELS WITH THREADED INSERTS OR PROTJECTING STUDS
-------------------------------------------------------------------------------
B [FNa1] T
A Minimum Outside Minimum Thickness
Diameter of Wheel Diameter of Flange of Flange
-------------------------------------------------------------------------------
Inches Inches Inches
1 ....................... 3/8 ........................ 1/8
2 ........................ 1 ......................... 1/8
3 ........................ 1 ........................ 3/16
4 ...................... 1 3/8 ...................... 3/16
5 ...................... 1 3/4 ....................... 1/4
6 ........................ 2 ......................... 3/8
[FNNote:] a1 Must be large enough to extend beyond the bushing. Where prong
anchor or cupback bushing are used, this footnote does not apply.
TABLE A-3
MINIMUM DIMENSIONS FOR STRAIGHT ADAPTOR FLANGE
--FOR ORGANIC BONDED WHEELS OVER 1 1/4 INCH THICK [FNa1]
-------------------------------------------------------------------------------
E
B D Minimum F*
Wheel Wheel Minimum Minimum Thickness of (D-E)
Diameter
Hole Flange Thickness of Flange at Edge Minimum
Diameter Diameter Flange at of Undercut Thickness
Bore
-------------------------------------------------------------------------------
Inches Inches Inches Inches Inches Inches
12 .......... 4 ......... 6 ........ 7/8 .......... 3/8 ......... 1/2
to .......... 5 ......... 7 ........ 7/8 .......... 3/8 ......... 1/2
14 .......... 6 ......... 8 ........ 7/8 .......... 3/8 ......... 1/2
-------------------------------------------------------------------------------
Larger than ..... 4 ......... 6 ........ 7/8 .......... 3/8 ......... 1/2
14 .......... 5 ......... 7 ........ 7/8 .......... 3/8 ......... 1/2
to .......... 6 ......... 8 ........ 7/8 .......... 3/8 ......... 1/2
18 .......... 7 ......... 9 ........ 7/8 .......... 3/8 ......... 1/2
8 ........ 10 ........ 7/8 .......... 3/8 ......... 1/2
-------------------------------------------------------------------------------
Larger than ..... 6 ......... 8 ......... 1 ........... 1/3 ......... 1/8
18 .......... 7 ......... 9 ......... 1 ........... 1/2 ......... 1/2
to .......... 8 ........ 10 ......... 1 ........... 1/2 ......... 1/2
24 .......... 10 ....... 12 ......... 1 ........... 1/2 ......... 1/2
12 ....... 14 ......... 1 ........... 1/2 ......... 1/2
-------------------------------------------------------------------------------
Larger than
24 to 30 ....... 12 ....... 15 ......... 1 ........... 1/2 .......... 1/2
-------------------------------------------------------------------------------
Larger than
30 to 36 ....... 12 ....... 15 ....... 1 3/8 ......... 7/8 .......... 1/2
-------------------------------------------------------------------------------
[FNa1] For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of
wheel thickness.
TABLE A-4
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES--FOR MECHANICAL
GRINDERS
12,500 S.F.P.M. to 16,5000 S.F.P.M. [FN1]
-------------------------------------------------------------------------------
'E' Minimum
'B' Minimum 'D' Minimum Thickness of F [FNa1]
(D-E)
Wheel Wheel Hole Flange Thickness of Flange at Edge Minimum
Diameter Diameter Diameter Flange at of Undercut Thickness
Bore
-------------------------------------------------------------------------------
20 ........ 6 .......... 8 ............ 1 ........... 1/2 ........ 1/2
20 ........ 8 .......... 10 ......... 1 1/2 ......... 3/4 ........ 3/4
24 ........ 12 ......... 15 ........... 2 ............ 1 .......... 1
30 ........ 12 ......... 15 ........... 2 ............ 1 .......... 1
36 ........ 12 ......... 15 ........... 2 ............ 1 .......... 1
-------------------------------------------------------------------------------
[FN1.]FLANGES shall be of steel, quality SAE 1040 or equivalent, annealed
plate, heat treated to R 25-30.
[FNa1] For wheels under 1 1/4 inch thick F dimension shall not exceed 40% of
wheel thickness.
TABLE A-5
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES USED AS
WHEEL SLEEVES FOR PRECISION GRINDING ONLY
-------------------------------------------------------------------------------
E
B D Minimum
Minimum Outside Minimum Thickness of
Thickness
Wheel Diameter of of Flange Flange at edge
Wheel Diameter Hole Flange at Bore of Undercut
Diameter
-------------------------------------------------------------------------------
Inches ....... Inches ....... Inches ......... Inches ........ Inches
12 to 14 ......... 5 ............ 7 ............ 1/8 ........... 7/16
-------------------------------------------------------------------------------
5 ............ 7 ............ 3/8 ........... 7/16
6 ............ 8 ............ 3/8 ........... 7/16
Larger than 14
to 20 ............. 8 ........... 10 ............ 3/8 ........... 7/16
10 ......... 11 1/2 .......... 3/8 ........... 7/16
12 ......... 13 1/2 .......... 3/8 ........... 7/15
-------------------------------------------------------------------------------
8 ........... 10 ............ 3/4 ............ 1/2
Larger than 20
to 30 ............ 10 ......... 11 1/2 .......... 3/4 ............ 1/2
12 ......... 13 1/2 .......... 3/4 ............ 1/2
15 ......... 17 1/2 .......... 3/4 ............ 1/2
-------------------------------------------------------------------------------
12 ......... 13 1/2 .......... 3/4 ............ 1/2
16 ......... 17 1/2 .......... 3/4 ............ 1/2
Larger than 30
to 42 ............ 18 ......... 19 1/2 .......... 3/4 ............ 1/2
20 ......... 21 1/2 .......... 3/4 ............ 1/2
-------------------------------------------------------------------------------
16 ........... 20 ............. 1 ............. 3/4
Larger than 42
to 60 ............ 20 ........... 24 ............. 1 ............. 3/4
24 ........... 29 ........... 1 1/8 ........... 7/8
-------------------------------------------------------------------------------
[FNNote:] These flanges may be clamped together by means of a central nut, or
by a series of bolts or some other equivalent mans of fastening. For hole
sizes smaller than shown in this table, use table A-1.
TABLE A-6
GUIDE FOR CONSTRUCTION OF BAND TYPE GUARDS
Maximum Wheel Speed 7000 SFPM
-------------------------------------------------------------------------------
Maximum
Thickness Distance
Minimum Thickness Minimum between
Material Diameter of of Band Diameter Centers of
Specifications Wheel A of Rivets Rivets
-------------------------------------------------------------------------------
Inches ....... Inches ..... Inches .... Inches
Under 8 ....... 1/16 ....... 3/16 ....... 3/4
Hot Rolled Steel SAE
1008 ...................... 8 to 24 ........ 1/8 ........ 1/4 ........ 1
Over 24 to 30 ...... 1/4 ........ 3/8 ...... 1 1/4
-------------------------------------------------------------------------------
TABLES A-7 through A-18
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix A
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix B
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
Appendix C
Note: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.Appendix D (continued)