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