... drilling or oil well drilling2,Model: various kinds and according to the requirements of customers3,Material: ally steel, tungsten carbide insert4 ... sealed(HJ) rubber sealed(HA) not sealed(W)11,Formation: soft formation, soft to medium hard formation, medium hard formation ,hard ... ,627,637,737512,522,532,612,622,632,7326. How to ship the bits to your country? You Satisfaction Is Our Purpose! We ...