SAFE USE OF GRINDERS OHS-PROC-125
7.4 Operation Safety – Allow the grinder to "run up" to operating speed before applying it to the job. – Never bump the grinder on to the job, or let the disc hit any other object while grinding. – Keep the grinding disc at a 15 to 30 degree angle to the work. – Make sure the work piece is held firmly in a bench vice, where necessary.