HSS step drill, especially for cable glands in electrical assembly, perfectly round and cylindrical holes in various diameters, centering, drilling, reaming and deburring in one operation, suitable for use in hand and pillar drills in trade and industry, for sheets and plates, profiles and pipes made of steel, brass, copper, aluminum, V2A steel, plastic, wood, etc. up to 3 mm thick. 12 mm shank, after hardening, additional TIN (titanium nitride) coated surfaces are extremely hard and smooth. Higher cutting speed allows faster work, less wear results in 5 to 10 times longer service life