The invention relates to a fastening screw, comprising an electrically insulating insulating body and a metal body formed from a metal and having an external thread. The metal body is fastened on the insulating body and has a first axial end and a second axial end opposite the first axial end, wherein the first axial end is remote from a screw head of the fastening screw. It is provided that the insulating body, by means of a shaft portion, emerges from the first axial end of the metal body along the longitudinal axis (L) of the metal body.