Mainly for roller bit for petroleum drilling, can also for small and medium-sized button bit, DTH bit. Mainly for roller bit for petroleum drilling, can also for small and medium-sized button bit, DTH bit. With good wear ability and better impact toughness, it can be for percussion drilling. Specification:sizeDiameter(MM)Height(MM)Radius of sphere top(MM)JCB101610.4016.005.50JCB131813.4018.007. ...