... 3)This cutting structure design, combined with maximum cone offset, results in high bit penetration rates.4)The deep intermesh of cutter rows ... BitCutting StructureThe durability of premium tungsten carbide inserts is improved with new formulas and new techniques for insert bit.Gauge ... 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", etc ...