Abstract: This invention relates to a screw tap which is rotatable about a rotational axis and has a number of thread-cutting teeth, which respectively have a radially outer tip cutter and are disposed mutually offset, with a predefined thread pitch, in an arrangement running spirally or helically around the rotational axis. In a lead region adjoining one end of the screw tap axially to the rotational axis, the maximum radial distance of the tip cutters of the thread-cutting teeth from the rotational axis increases with increasing axial distance of the tip cutters from one end of the screw tap according to a predefined radial distance function. At least some of the thread-cutting teeth in the lead region, at least in the region of the tip cutters, respectively have a defined cutter rounding between tool face and tool flank.