... with maximum cone offset, results in high bit penetration rates.4)The deep intermesh of ... new formulas and new techniques for insert bit.Gauge StructureMultiple gauge protection with gauge trimmers ... new formulas and new techniques for insert bit.Bearing StructureNon-sealed roller bearing. Drilling fluid ... 8",4",4 1/2",4 5/8",4 3/4",6",6 1/2",7 1/2",8 1/2",9 1/2",9 5/8",9 7/8",12 1/4",15",15 1/2",17 1/2 ...