PDC Drill Bits, Tricone Bits, DTH Hammer manufacturer / supplier in China, offering 3 Blades Step Face Carbide Drag Bits for Water Well Drilling, Mining, 4 ⅝ " Short 3 Step 3 Wing Step Drag Bit 2 ⅜ " Reg Pin Thread, Top Quality Mining Tool API Thread Connect 4" Stepped Drag Bit and so on.