Rock Drill Bit for Mining and Well Borehole, Rock Drill Rod for Tunneling and Open Mining, Tricone Roller Bit and PDC Drag Bit for Borewell manufacturer / supplier in China, offering Hex22/Hex25*108mm/159mm Shank Taper Drill Rod, Slide Block Guide Concentric Reaming Casing System Drill Bit, Numa100 Numa125 Super Jaws Slide Block Casing Drilling System with Guide Device and so on.