Tricone Bit, PDC Bit, Hole Opener manufacturer / supplier in China, offering 6 3/4 Inches 6 Blades 13mm Cutter Hard Rock PDC Drilling Bit, 6 1/2 Inches 165mm 6 Blades 13mm Cutters PDC Drill Bit, 8 Inche 4 Wings 19mm Cutters Oilfiled Drill PDC Bit and so on.