... TypeTri-cone bits, Steel tooth bits, PDC bits Applicablewater well, oil field, construction, geothermal, directional boring, and underground foundation work Formationsticky ... )Type tricone bits,steel tooth bits, PDC bitsApplicable water well,oil field, construction, geothermal, directional boring,and underground foundation work. ... 311.1(12 1/4”),346.0 (13 5/8”),349.2(13 3/4”)374.6(14 3/4”)381(15”),393.7 ...