10 Diamond Coated Cutting Wheels Jewelers Lapidary Tool. 5 Diamond Coated Cutting Wheels & 2 Mandrels. This is a new set of 5 diamond coated 240 grit cutting wheels and 2 mandrels. These are used for cutting, grinding, cleaning, etc. One mandrel has a 1/8 (3 mm) shank and the other has a 3/32 (2.5 mm) shank. Each wheel measures approximat...