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(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.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New section filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLE A-1
MINIMUM DIMENSIONS FOR STRAIGHT RELIEVED FLANGES
MINIMUM DIMENSIONS FOR STRAIGHT RELIEVED FLANGES(1)
(In inches)
__________________________________________________________________
| | | |
A-- | B-- | C-- Radial width of | D-- | E--
Diameter| Minimum | bearing surface | Minimum | Minimum
of | outside |_____________________| thickness | thickness
Wheel | diameter| | | of | of flange
| of | Minimum | Maximum | flange | at edge
| flanges | | | at bore | of recess
________|_________|__________|__________|___________|_____________
| | | | |
1 ..... | 3/8 | 1/16 | 1/8 | 1/16 | 1/16
2 ..... | 3/4 | 1/8 | 3/16 | 1/8 | 3/32
3 ..... | 1 | 1/8 | 3/16 | 3/16 | 3/32
4 ..... | 1 3/8 | 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 | 1/2 | 3/8 | 3/16
8 ..... | 3 | 1/4 | 1/2 | 3/8 | 3/16
10 .... | 3 1/2 | 5/16 | 5/8 | 3/8 | 1/4
12 .... | 4 | 5/16 | 5/8 | 1/2 | 5/16
14 .... | 4 1/2 | 3/8 | 3/4 | 1/2 | 5/16
16 .... | 5 1/2 | 1/2 | 1 | 1/2 | 5/16
18 .... | 6 | 1/2 | 1 | 5/8 | 3/8
20 .... | 7 | 5/8 | 1 1/4 | 5/8 | 3/8
22 .... | 7 1/2 | 5/8 | 1 1/4 | 5/8 | 7/16
24 .... | 8 | 3/4 | 1 1/4 | 5/8 | 7/16
26 .... | 8 1/2 | 3/4 | 1 1/4 | 5/8 | 1/2
28 .... | 10 | 7/8 | 1 1/2 | 3/4 | 1/2
30 .... | 10 | 7/8 | 1 1/2 | 3/4 | 5/8
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
________|_________|__________|__________|___________|_________
*Flanges for wheels under 2 inches diameter may be unrelieved
and shall be maintained flat and true.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLE A-2
MINIMUM DIMENSIONS FOR STRAIGHT UNRELIEVED FLANGES
FOR WHEELS WITH THREADED INSERTS OR PROJECTING STUDS
B* 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
NOTE: *Must be large enough to extend beyond the bushing. Where prong anchor or cupback bushing are used, this footnote does not apply.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLE A-3
MINIMUM DIMENSIONS FOR STRAIGHT ADAPTOR FLANGE
--FOR ORGANIC BONDED WHEELS OVER 1 1/4 INCH THICK *
___________________________________________________________________
| | | | |
| | B- | D- | E- | F(1)-
| Wheel | Minimum | Minimum | Minimum | (D-E)
Wheel | hole | flange | thickness | thickness | minimum
diameter | diameter | diameter | of flange | of flange | thickness
| | | at bore | at edge of|
| | | | undercut |
___________|__________|__________|___________|___________|__________
| | | | |
12 to 14...| 4 | 6 | 7/8 | 3/8 | 1/2
| 5 | 7 | 7/8 | 3/8 | 1/2
| 6 | 8 | 7/8 | 3/8 | 1/2
Larger | | | | |
than 14 | | | | |
to 18.....| 4 | 6 | 7/8 | 3/8 | 1/2
| 5 | 7 | 7/8 | 3/8 | 1/2
| 6 | 8 | 7/8 | 3/8 | 1/2
| 7 | 9 | 7/8 | 3/8 | 1/2
| 8 | 10 | 7/8 | 3/8 | 1/2
Larger | | | | |
than 18 | | | | |
to 24.....| 6 | 8 | 1 | 1/2 | 1/2
| 7 | 9 | 1 | 1/2 | 1/2
| 8 | 10 | 1 | 1/2 | 1/2
| 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
___________|__________|__________|___________|___________|__________
*For wheels under 1 1/4 inch thick F dimension shall not exceed 40%
of wheel thickness.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLE A-4
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES
--FOR MECHANICAL GRINDERS 12,500 S.F.P.M. to 16,500 S.F.P.M.1
___________________________________________________________________
| | | | |
| | | D-- | E-- | F(2)--
| Wheel | B-- | Minimum | Minimum | (D-E)
Wheel | hole | Minimum | thickness | thickness | minimum
Diameter | diameter | flange | of | of flange | thickness
| | diameter | flange | at edge of |
| | | at bore | undercut |
__________|__________|__________|___________|____________|___________
| | | | |
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) FLANGES shall be of steel quality, SAE 1040 or equivalent, annealed
plate, heat treated to R 25-30.
* For wheels under 1 1/4 inch thick F dimension shall not exceed 40%
of wheel thickness.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLE A-5
MINIMUM DIMENSIONS FOR STRAIGHT FLANGES
USED AS WHEEL SLEEVES FOR PRECISION GRINDING ONLY
_______________________________________________________________
| | | |
| | B-- | D-- | E--
Wheel | Wheel | Minimum | Minimum | Minimum
diameter | hole | outside | thickness | thickness
| diameter | diameter | of flange | of flange
| | of flange | at bore | at edge of
| | | | undercut
_______________|__________|___________|___________|_____________
| | | |
12 to 14.......| 5 | 7 | 1/2 | 7/16
Larger than | | | |
14 to 20......| 5 | 7 | 5/8 | 7/16
| 6 | 8 | 5/8 | 7/16
| 8 | 10 | 5/8 | 7/16
| 10 | 11 1/2 | 5/8 | 7/16
| 12 | 13 1/2 | 5/8 | 7/16
Larger than | | | |
20 to 30......| 8 | 10 | 3/4 | 1/2
| 10 | 11 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......| 12 | 13 1/2 | 3/4 | 1/2
| 16 | 17 1/2 | 3/4 | 1/2
| 18 | 19 1/2 | 3/4 | 1/2
| 20 | 21 1/2 | 3/4 | 1/2
Larger than | | | |
42 to 60......| 16 | 20 | 1 | 3/4
| 20 | 24 | 1 | 3/4
| 24 | 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 ohter equivalent means of
fastening. For hole sizes smaller than shown in this table, use
table A-1.
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLE A-6
GUIDE FOR CONSTRUCTION OF BAND TYPE GUARDS
Maximum Wheel Speed 7000 SFPM
__________________________________________________________________
| | | |
Minimum | | Minimum | Minimum | Maximum
material | Diameter | thickness | diameter | distance
specifications| of | of band A | of rivets | between
| wheel | | | centers
| | | | of rivets
______________|_______________|___________|___________|___________
|
| Inches
______________|___________________________________________________
| | | |
Hot rolled | | | |
steel SAE | | | |
1008 ........| Under 8...... | 1/16 | 3/16 | 3/4
| 8 to 24...... | 1/8 | 1/4 | 1
| Over 24 to 30 | 1/4 | 3/8 | 1 1/4
______________|_______________|___________|___________|___________
NOTE: Authority cited: Section 142.3, Labor Code. Reference: Section 142.3, Labor Code.
HISTORY
1. New NOTE filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
TABLES A-7 through A-18
HISTORY
1. New Tables A-7 through A-18 filed 7-26-78; effective thirtieth day thereafter (Register 78, No. 30).
2. Repealer of Tables A-7 through A-18 filed 11-22-85; effective thirtieth day thereafter (Register 85, No. 48).
Appendix A
Appendix B
Appendix C
Appendix D
Appendix E
Appendix F
Appendix G
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