Tungsten carbide insert bit ,TCI bit,button bit Sizes range ... system. 1.Cutting structureThe durability of premium tungsten carbide insert is improved with new formulas and new techniques2.Gauge ... inserts on the surface of the cone, tungsten carbide inserts and hardfacing on the shirttail increases gauge holding ... 241, 537….………..………………………………26 131, 211, 537, 517…. Tungsten carbide insert tooth rock bit