... "(311mm), 13 5/8"(346mm),14 3/4"(374mm), 15 1/2"(394mm)16"(406mm), 17 1/2"(445mm),18"(457mm), 26"(660mm)Model ... and gas, water well, mining and tectonic industries, oil field, construction, geothermal, directional boring and underground foundation work1>Cutting ... reliability. 5>Product Application It can receive high WOB in the conventional drilling. It is suitable for various formations ...