Portable abrasive grinders

Hazards

The hazards associated with portable grinders are similar to those of pedestal or bench grinders. First of all, serious abrasion or cuts can occur from contacting the rotating abrasive stone. There is also the potential for the abrasive stone to shatter, plus the dangers of exposure to the rotating wheel, flange, and spindle end from kickback. Finally, other concerns such as flying fragments and sparks are present during portable grinding operations.

Solutions

These types of grinders normally come with the manufacturer’s safety guard covering most of the wheel. Abrasive grinder exposure must not exceed a maximum angle of 180 degrees and the top half of the wheel must be enclosed at all times. The guard must be mounted so it maintains proper alignment with the wheel.

Vertical “right angle” grinders must have a 180 degree guard between the operator and wheel. The guard must be adjusted so that pieces of a broken wheel will be deflected away from the operator.

Cup wheel grinders must be guarded as described above or be provided with special “revolving cup guards,” which mount behind the wheel and turn with it.

Note: There are exceptions in the OSHA standards for guarding based on work practices and for other grinders. (See 1910.243(c)(1)(i) and (c)(1)(ii))

All abrasive wheels must be closely inspected and “ring-tested” before mounting to ensure that they are free from cracks or other defects. The spindle speed of the machine also must be checked before mounting the wheel to be certain that it does not exceed the maximum operating speed marked on the wheel.

Always follow the manufacturer’s recommendations.

References

29 CFR 1910.243(c)

29 CFR 1926.303

ANSI B7.1 Safety Code for the Use, Care, and Protection of Abrasive Wheels

ANSI/UL 45-1990 Portable Electric Tools

ANSI B11.9 Safety Requirements for Grinding Machines