for grinding and polishing hard brittle things like ceramics, teeth, glass, granite and marble etc precise,fast,sharp,long life Jiu Feng Diamond Tools CO., LTD Quality First, Honesty, Seeking for Perfection, Reliabilityconcave diamond grind disc 1. Specifications Base body65MnBody materialcorundum & MnGrit20# /80#Handle diameter2mmHead shaperound,square Specialtyallotype2. ApplicationsTo cut hard ...