PDC Drill Bits, Tricone Bits, DTH Hammer manufacturer / supplier in China, offering Non Saled Roller Air Bearing Mining TCI Tricone Roller Cone Bits for Oil Drilling, 6 1/8 Tricone Drilling Bits IADC 337 317 537 9 Tricone Bit for Hard Rock Well Drilling, Tricone Bit Factory 6 1/2 Inch IADC 537 TCI Tricone Drill Rock Bit and so on.