... Tricone Drill Bits 1-API or ISO 9001:2008 2-Delivery Date: In 7 days 3-Delivery term: By sea/ ... beds, and clays, with high durability and maximum penetration rates. 2,Soft to medium formations(121,124,126,134,136,137 ... , 617G, 627G, 637G9 1/2241.3437G, 517G, 537G, 547G, 617G9 5/8244.5437G, 517G, 537G, 547G, 617G9 7/8250.8437G, 517G ... 1/2444.5517G, 537G, 617G, 627G, 637G API 8 1/2" steel cone bit