Protective cap to be placed over a political tool shank that consists of an at least partly ring-shaped casing, on which, in the vicinity of a base part, a terminating ring with a ring-shaped insertion-guide profile is shaped, wherein the casing and the terminating ring together form a receptacle space for the tool shank, wherein in the direction in which the protective cap is pushed onto the tool shank, the base-side annular area transitions into a cover-side trochoidal area which is adapted to the polygonal shape of the tool shank.