N/a manufacturer / supplier in China, offering API TCI 8 1/2" Tungsten Carbide Insert Tricone Roller Bit, Best Quality API Factory 7 Blades 12 1/4′′ Inch 4 1/2" Inch Matrix/ Steel Body PDC Drill Bit in Stock, API Standard 7 Blades PDC Bit 6 1/2" 22" PDC Drill Bit Rock Drilling Bits for Oil Gas Drilling and so on.