N/a manufacturer / supplier in China, offering Borehole Tools IADC537 7-1/2′′ TCI Tricone Rock Roller Cone Drill Bit for Well Drilling, Steel Milled Tungsten Carbide Tooth Rock Roller Three Cones Tricone Drill Bit, PDC Bit Diamond PDC Bit API Standard for Water/Oilfield Well Drilling and so on.