1. Used for oil field and water well 2. Certified by ISO9001&API 3. High quality and best price 4. Sizes from 3 7/8" to 26"Size Bit Type In. mm 6 152.4 517G, 537G, 617G, 637G 6 1/2 165.1 517G, 537G 7 7/8 200.0 517G, 527G, 547G, 617G, 627G, 637G 8 1/2 215.9 437G, 447G, 517G, 537G, 617G, 627G, 637G 9 1/2 241.3 437G, 517G, 537G, 547G, 617G 9 5/8 244.5 437G, 517G, 537G, 547G, 617G 9 7/8 250.8 437G, 517G, 537G, 547G, 617G 12 1/4 311.1 437G, 517G, 537G, 617G, 627G, 637G 17 1/2 444.5 517G, 537G, 617G, 627G, 637G
