HSS TiAlN step drill bit with drilling diameter from 4 to 39 mm. Designed for drilling in non-ferrous metals, steel sheets and plastics. The drill bit is made of HSS high-speed steel with increased cutting ability and wear resistance. Coated with TiAlN (titanium aluminum nitride). The drill bits coated with a TiAlN layer are intended in particular for machining difficult-to-cut materials and wherever the drill will be subjected to high heat loads due to the lack of coolant or limited coolant supply. This coating significantly improves the wear resistance of the drill bits and allows to increase the cutting speed. The drill is packed in a plastic container with a hole for hanging on a hook. Technical data Type Step drill Material HSS steel Layer TiAlN  Chuck cylidrical Diameters [mm] 4, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39 Stepped every 2 mm Total length [mm] 107 Working length [mm] 82