tapered drill bits,chisel bits,button bits,cross bits,rock drilling bit,sandvik,high quality blade bit,cross bit Xiamen Betopper Mining Machinery Co ... Drill Bits , Chisel Drill Bits, Taper Drill Rods, Thread Drill Bits and other Rock Tools.1. Bit Type: high quality ... rock drilling condition because of it's comprehensive adaptability.Taper chisel bit is mainly used for hard rock, tapered cross bits ...