Editing Bench grinder (section)

===Tool rest and spark arrester placement===
The tool rest needs to be tight and within 2 to 3 mm of the wheel ({{frac|1|16}}" to {{frac|1|8}}"). This prevents the workpiece from slipping down between the wheel and the tool rest. The spark arrestors catch stray sparks.

Grinding is usually done with the workpiece resting on the tool rest. This prevents sudden slips in which the wheel grabs the work momentarily and yanks it out of the operator's hand or pulls the hand toward the wheel.