(1) Immediately
before mounting, the operator must closely inspect and sound (ring test) all
wheels to make sure they are not damaged. Before mounting the wheel, the
operator must check the spindle speed of the machine to be certain that it does
not exceed the maximum operating speed marked on the wheel.
Ring test. To tap the wheel
gently with a light nonmetallic implement, such as the handle of a screwdriver
for light wheels, or a wooden mallet for heavier wheels.
(2) Grinding wheels must fit freely on the
spindle and remain free under all grinding conditions. The wheel hole must be
made suitably oversized to ensure that heat and pressure do not create a
hazard.
(3) All contact surfaces of
wheels, blotters, and flanges must be flat and free of foreign
matter.
(4) Bushings used in the
wheel hole must not exceed the width of the wheel and must not contact the
flanges.
(5) On offhand grinding
machines, work rests must be used to support the work. The work rest must be
rigid and adjustable to compensate for wheel wear. Work rests must be kept
adjusted closely to the wheel with a maximum opening of one-eighth inch to
prevent the work from jamming between the wheel and the rest. The work rest
must be securely clamped after each adjustment and must not be adjusted with
the wheel in motion.
(6) Goggles or
face shields must be used when grinding.
(7) Nonportable grinding machines must be
securely mounted on substantial floors, benches, foundations, or other adequate
structures.
(8) After mounting,
abrasive wheels must be run at operating speed with the safety guard in place
and properly adjusted, or in a protected enclosure for at least one minute
before applying work. During this time, no one may stand in front of or in line
with the wheel.
(9) Grinders or
abrasive wheels that vibrate or are out of balance must be repaired before
use.
(10) Abrasive wheels not
designed for the machine or guard must not be mounted on a grinder.
(11) Side grinding must only be performed
with wheels designed for this purpose.
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Note:
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Light grinding on the side of straight wheels is
permitted only when very delicate pressure is applied. |
(12) Where the operator may stand in front of
the opening, safety guards must be adjustable to compensate for wheel wear. The
distance between the wheel periphery and the adjustable tongue or the guard
above the wheel must not exceed one-quarter inch.
