tapered drill bits,chisel bits,button bits,cross bits,rock drilling bit,sandvik,high quality blade bit,cross bit Xiamen Betopper Mining Machinery Co., Ltd. is manufacturer and exporter of Rock Tools such as Cross Drill Bits , Chisel Drill Bits, Taper Drill Rods, Thread Drill Bits and other Rock Tools.1. Bit Type: high quality blade bit2. Diameter : 28mm - 65mm3. Taper: 6°, 7 °, 11°, 12°4. Bottom ...