Tricone Bit, PDC Bit, Hole Opener manufacturer / supplier in China, offering 6 1/4''inches IADC 627y Conical Tricone Carbide Inserts Drilling Bit, 171mm IADC 535 Roller Bearing Jet Tricone Drilling Chisel Bit, 3 1/2''89mm Milled Tooth Roller Chisel Tricone Drill Bit Supplier and so on.