spare parts of drilling machne,tapered button bits,button bits,rock ... sandvik,atlas copco bits Xiamen Betopper Mining Machinery Co., Ltd offer different kinds of taper bits, all taper ... and taper cross bits.1. Bit Type: spare parts of drilling machine2. Diameter : 28mm – 45mm3. Taper: 7 degree, 11 ... pressed on bits bodies, they have a very good drilling performance and long life time. Usually used for ...