PDC Drill Bits, Tricone Bits, DTH Hammer manufacturer / supplier in China, offering 8 1/2 216mm Oil Drilling Roller Tricone TCI Bit Petroleum Machinery Drill Tool, 10 5/8 269mm IADC 617 Oil Drilling Roller Tricone TCI Bit Petroleum Machinery Drill Tool, TCI Tooth Type Tricone Drill Bit for Oil Gas Water Mineral Well Drilling and so on.