... hole surface and long tool life, the effective of drilling is much better and quicker than the common drills;2 ... geometry,smooth cutting;3. It can be widely used in drilling hard-cutting materials: steel, copper, aluminum, stainless steel, plates ... , hougen, jancy, alfra, bds, ruko, rotabroach; as well as radial drilling machine, boring machine, milling machine;6. Blade cutting resistance reduced ...