Drill Bit, TCI Tricone Bit, PDC Bit manufacturer / supplier in China, offering Hard Formation IADC 637 Water Well Tricone Bit 8 1/2′′, 9 7/8′′ IADC 637 TCI Tricone Drill Bit for Hard Formation, 215.9mm Insert Steel Tooth Tricone Rock Roller Bit Oil Drilling Equipment and so on.