TEST YOUR GRINDER SAFETY KNOWLEDGE
WEBJun 22, 2011 · D) Tapping a grinding wheel shakes any impurities out of its pores. 5. When gauging the compatibility between a grinder's RPM and a grinding wheel's RPM, remember: A) The two numbers must be exactly the same. B) The two numbers are not connected. C) The rpm of the grinder is always twice that of the grinding wheel. D) .