Rock Drill Bits 45mm, 48mm, 51mm, 64mm, 76mm, 89mm, 102mm, 115mm R25, ... , R38, T38, T45, T51 apered: 7 degs,11degs,12degs. Rock Drill Bits Rock Drilling Tools---Button Bits, Cross Bits, Chisel Bits ... : 7 degs, 11degs, 12degs.They are widely used in mountains, mining, railways, constructions, etc.Our products are in good quality and ...