TiN Coated CNC Heavy Duty Spiral Point taps are designed to tap difficult to machine hard materials such as heat-treated steels, tool steels, and some hard exotic materials up to 35 Rc. Spiral Point CNC Heavy Duty Taps, which drive the chips ahead of the tool, are recommended for through holes or blind holes with sufficient chip clearance. For blind holes, CNC Heavy Duty Spiral Fluted Taps are recommended. CNC taps are manufactured with closely controlled dimensions for fast, repeatable tool changes on CNC equipment.