Ultra-fine grit solid carbide, DIN 6527, with centre cut. Cutting speed approx. 50% higher than with non-coated tools. Dry machining possible. Air cooling recommended. The irregular spiral lead 35°/38° results in particularly smooth running and thus very good surface on the workpiece. A much longer tool life is achieved than with conventional tools, as well as maximum stability during machining. In addition, feeds higher by up to 60% can be realized.