ShearTap. ShearTap for Stainless Steel & Carbon Steel up to 35Rc hardness. CNC Styleenchances chip evacuation and cutting fluid flow to the cutting teeth for reduced friction, heat and galling. Also reduces contact between the tap and the workpiece. Semi-Bottoming Styleare designed to lift the chips sout of the hole in blind hole tapping, eliminating chip evacuation problems which can result in damaged threads and broken taps. They will also bridge opeings, keyways and other interruptions in the tapped hole. Steam Oxide over Nitrideincreases wear resistance, reduces friction, reduces galling and chip welding, improves chip flow and increases tap lubricant retention.