PDC Drill Bits, Tricone Bits, DTH Hammer manufacturer / supplier in China, offering 12 1/4 Inch Tricone Bit IADC437 for Oil Rig and Mining, 12 1/4′ ′ IADC 537 Oilfield Drill Tricone Bit, Milled Tooth Bit 11 5/8"Tricone Bit/ Rock Drill Bit/ Roller Cone Bit and so on.