Grinding Safeguards
(Taken from Construction Safety Magazine, Vol.12, No.1, Spring 2001)
|
|
Construction
Safety Association of Ontario
Secure or remove
any loose clothing that might get caught.
|
Grinders come in
bench and portable types. Common causes of injury on grinders are
- grinding wheels
flying apart
- hands touching
the wheel
- work getting hot
and burning fingers
- sparks and grindings
- work pulled into
the wheel.
Personal
Protective Equipment
- When operating
grinders, always wear proper eye protection. A face shield is
also recommended.
- Respiratory
protection suited to particular dust hazards may be required.
Use hearing protection.
- Wear gloves
and aprons where hot sparks are being generated
|
Bench Grinders
Bench grinders are
designed for jobs such as removing excess metal and smoothing metal surfaces.
The grinders are usually fitted with both a medium grain and a fine grain
abrasive wheel. When a considerable quantity of metal is to be removed,
it's often more practical to grind with the medium wheel first and finish
up with the fine wheel. A tool rest at the front of each wheel guides
the work during grinding.
Operation
- Before grinding,
check the wheel for cracks or chips and replace if necessary. Use the
ring test (see box).
- Remove any flammable
material from the work area. Sparks can cause fire or explosion.
- Secure or remove
any loose clothing that might get caught in the grinder.
- Adjust the tool
rest so that it just clears the wheel and is above the wheel's center
line. This keeps work from jamming between tool rest and wheel.
- Never adjust the
tool rest while the wheel is turning.
- Before starting,
make sure guards are in place and working properly.
- Stand to one side,
turn on the grinder, and let the machine come up to full speed. There's
always a chance a wheel may break up and fly apart.
- Never force work
against a cold wheel. Apply work gradually to give the wheel time to
warm up.
- Always keep the
work moving across the face of the wheel. This prevents grooves from
being worn into the wheel.
- Never grind on
the side of the wheel. Side pressure can break wheels not designed for
that use.
- Maintain good
footing. Floor may become slippery with grindings.
- Keep guards in
place during operation.
Replacing wheels
- Follow manufacturer's
instructions.
- Unplug the tool.
- Use the proper
hardware--safety flanges, nuts, blotters--to hold wheels in position.
- Always check the
speed rating on the wheel and on the grinder to make sure that both
are compatible.
- Tighten the spindle
nut just enough to hold the wheel. Too tight and you may damage the
wheel.
Ring
Test
- Clean
material from grinding wheel.
- Let wheel
dry before testing.
- Tap wheel
with something nonmetallic such as a screwdriver handle.
- Tap 1/2
inch from outside rim.
- Rotate
wheel 45 degrees and repeat test.
- A sound,
undamaged wheel will give off a clear metallic ring. A cracked
wheel will give off a dull sound with little or no ring
|
Portable
Grinders
Portable grinders
can be difficult to handle because of their size and weight. Some of
the safeguards that apply to bench grinders--such as the ring test--also
apply to portable grinders. In addition, operators should take the following
precautions.
- Use light pressure
when starting to grind, especially with a cold wheel. Too much pressure
may cause a cold wheel to crack and fly apart.
- Hold the grinder
firmly with both hands and grind with moderate pressure.
Let
the grinder come to a complete stop before laying it down.
- To avoid kickback,
hold the grinder so that the rotating wheel pulls away from
you.
- Avoid sending
sparks upward. Where practical, direct sparks sideways or downward.
- Always unplug
the tool before replacing or installing stones, disks, and cutters.
- Use welding
screens or other suitable barriers to contain sparks and grindings.
- Let the grinder
come to a complete stop before laying it down.
- Handle portable
grinders with care to prevent dropping. Inspect dropped grinders carefully
for cracked or broken wheels.
- Check the surrounding
area for any people or property that might be hit by sparks. Make
sure there are no flammables that could be ignited.
This paper
appears in the eLCOSH website with the permission of the author and/or
copyright holder and may not be reproduced without their consent. eLCOSH
is an information clearinghouse. eLCOSH and its sponsors are not responsible
for the accuracy of information provided on this web site, nor for its
use or misuse.
eLCOSH
| CDC | NIOSH
| Site Map | Search
| Links | Help
| Contact Us | Privacy Policy
|