Diamond Grinding Bits | McMasterCarr
The diamond abrasive in these bits is extremely hard and lasts longer than tungsten carbide. For longer tool life and improved finish, use a water or oilsoluble mist or coolant.. Bits are also known as mounted points and die grinder bits. Head diameter is measured at the widest point.. Caution: As bit shank is exposed beyond 1/2 ", maximum safe rpm decreases significantly.