• ONYX TAP – for tapping a wide range of materials up to 28Rc hardness.• CNC Style enchances 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 Style are 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 Nitride increases wear resistance, reduces friction, reduces galling and chip welding, improves chip flow and increases tap lubricant retention. NOT RECOMMENDED FOR NON-FERROUS MATERIALS.