A socket spanner insert releases or fastens wheel bolts which in the mounted state rest inside wheel bolt holes of a car rim. The socket spanner insert includes a base body which has a screw head receptacle and a tool receptacle, and a sleeve which encompasses the base body at least in portions and is rotatably connected to the base body. In order to prevent damage to the rims when mounting and removing wheel bolts, a retaining element is provided which, during release or fastening of the wheel bolt, blocks a relative rotational movement of the sleeve with respect to the car rim and allows a rotation of the base body within the sleeve.