... 5.Good concentricity Manufacturer of taper shank glass diamond drill bit with competitive price introduction:Diamond glass driller: using high ... to polish and not crack, high efficiency, long life, drill 4000-5000 holes/pc2.Main Market: Europe market.3. ... glass, Ceramics,cameo, stone, agate, sheel, tile and other hard materials4.Complete specification: Straight shank, Taper shank ,thread shank. Special ...