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Grinding stone incident

We have received information of an incident involving a cup grinding stone. In this incident, the cup stone exploded. However, the findings are considered applicable to any type of abrasive wheel.

In the incident, a pipe welder was using a pneumatic grinder to bevel the end of a 3″ pipe when the grinding stone exploded, striking the welder on his shoulder.

The investigation revealed that the guard used on the grind was not the correct one for a cup stone and that the flange was not the correct size for the stone.

The following common errors were identified in the use of grinding stones:

  1. use of flanges of uneven or too small diameter;
  2. use of washers instead of flanges;
  3. flanges without proper clearance or relief;
  4. excessive tightening, causing flanges to bend;
  5. failure to clean all dirt and foreign material from sides of wheels and flanges;
  6. forcing a wheel onto an arbour where fit is tight;
  7. use of any loose washers or bushings to try to make a wheel fit a machine for which it is not intended;
  8. failure to use blotters on wheels.

Safety Event

Published: 1 July 2001
Download: IMCA SF 07/01

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