PDC Drill Bits, Tricone Bits, DTH Hammer manufacturer / supplier in China, offering 7 7/8′ ′ IADC 517 Reverse Circulation Rock Drilling Tricone Bit, Mining Bits, 14 3/4′ ′ IADC 637 Tricone Rock Bits for Hard Rocks Drilling, 9 1/2′ ′ IADC 537 Medium Hard Rock Drilling Tricone Three Roller Cone Bit and so on.