Tricone Bit, PDC Bit, Hole Opener manufacturer / supplier in China, offering 171mm IADC 515 Tricone Tungsten Caibide Inserts Bit Borehole Driling Bit, 6 1/4''inches IADC 627y Conical Tricone Carbide Inserts Drilling Bit, 171mm IADC 535 Roller Bearing Jet Tricone Drilling Chisel Bit and so on.