tapered drill bits,chisel bits,button bits,cross shaped drill bits,rock drilling bit,sandvik,atlas copco 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: cross shaped drill bits 2. Diameter : 28mm - 65mm3. Taper: 6°, 7 °, 11°, ...