8 1/2" Steel Tricone Drill Bits 1-API or ISO ... cherty streaks Model6-26( inch) TypeTricone bits, Steel tooth bits, PDC bits Applicable water well, oil field, construction, geothermal, directional boring ... , 627G, 637G17 1/2444.5517G, 537G, 617G, 627G, 637G API 8 1/2" steel cone bit