PDC Drill Bits, Tricone Bits, DTH Hammer manufacturer / supplier in China, offering TCI and Toothed Type Tricone Drill Bit for Oil Gas Water Mineral HDD Drilling, Factory Steel Tooth Type IADC 221 Tricone Drill Bit for Oil Gas Well Drilling, Factory Size 6", 6 1/2", 8", 8 1/2" 12 1/4" Tricone Drill Bit for Oil Gas Water Well Drilling and so on.