... deformation 4 long life Diamond glass core drill bits are used to drill glass,ceramics, porcelain, ceramic, porcelain ... ,95mmService life: can dig 4000 to 8000 holesDrill bit type:1. Straight shank2. Cone/taper shank3. ... 0.8mm-1mmAll these drill bits can be customized.This is the diamond drill bit we are producing: Other ... be customized. thin wall diamond core drill bit with threaded shankfor glass