Diameter in the groove laser-sintered, the special shank prevents slipping in the drill chuck, for burr-free drilling and reaming of sheet metal, pipes and profiles, works without burrs and chatter marks and can be used in hand or column drilling machines, straight grooved, for sheet steel 0, 1-2 mm, stainless steel sheet (V2A) 0.1-1 mm, plastics up to 10 mm, non-ferrous metals 0.1-5 mm, additionally surface-hardened, thereby increasing hardness to over 1000 HV, tenifer-coated