Posted By Richard Everitt The Provision and Use of Work Equipment Regulations 1998 requires that anyone involved in mounting, dressing or setting abrasive wheels is trained and certified. My question is; What about 4½" Angle Grinder(hand power tool) is a Cert required? Many thanks Richard.

Posted By Crim YES. It is possible to remove the guard and fit an oversize disc. That leads to the outer edge of the disc spinning faster than designed and could shatter. One reason for such training and certification.