Current through Register 2024 Notice Reg. No. 38, September 20, 2024
(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.
1. New
section filed 11-22-85; effective thirtieth day thereafter (Register 85, No.
48).
Note: Authority cited: Section
142.3, Labor
Code. Reference: Section
142.3, Labor
Code.
