... We have been in line with the principle of "faith-based, quality of survival and mutual benefit, provides the highest quality ... streaks Model6-26( inch) TypeTricone bits, Steel tooth bits, PDC bits Applicable water well, oil field, construction, geothermal, directional ... 517G, 537G, 547G, 617G12 1/4311.1437G, 517G, 537G, 617G, 627G, 637G17 1/2444.5517G, 537G, 617G, 627G, 637G API 8 1/2" steel cone bit