... Cangzhou city ,and enjoys good location and convenient transportation.Huanyu specializes in water well drill bits,oil well drilling bits ,like ... used for mining pilling, water well drilling or oil well drilling2,Model: various kinds and according to the requirements of ... cutters8,Certification: API9,Applicable of: petroleum&gas,water well and mining10,Bearing sealed: metal sealed(HJ) rubber sealed(HA ...