diamond drill bit: HP, medium, diamond coated for grinding, engraving, carving on metal, wood, bone, jade, PVC, glass, stone Catalog: ... on PFM, chrome & ceramic materials;3. Also for grinding and engraving on metal, wood, bone, jade, PVC, glass and stone carving ... , can be used as glass drill bit, diamond drill bit, jewelry drill bit and engraving bit;4. 3 grits for selection.About Us ...