The invention relates to a surgical locking screw for fastening bone parts in the event of a heel fracture, comprising a front end, a rear driving end having a drive for turning the locking screw, and an external thread, which has a constant thread pitch continuously over the axial extent of the external thread, wherein a major diameter of the external thread is constant in a first axial segment of the locking screw and increases with increasing distance from the front end in a second axial segment adjacent to the first axial segment in the direction of the rear end, wherein a minor diameter of the external thread is constant in the first and second axial segments, wherein the external thread extends, at least approximately, axially continuously over the entire axial extent of the locking screw, and wherein the minor diameter of the external thread extends over the entire axial extent of the external thread.
