... (6, 7, 11, 12 degree taper).Bit diameter: 28mm-57mm.3. Extension drilling toolsButton bit, face design: Flat face, Drop centre, Normal and ... kinds of round cutter bit and flat cutter bits for excavate coal machine as the replacements of kennametal. Such as U76, U82, U84 ... , U85, U92, U94, U95, U118 and coal bolting bit and coal ...