Abstract: A corrosion protection cap for clamping onto a polygonal wheel nut, having a cylindrical casing which engages over the polygonal wheel nut, and having groove profiles formed in the web of a spring ring, which are open toward the casing axis and of which the vertices in each case correspond to the corners of the polygonal nut profile and the distance of the vertices from the casing axis is slightly less than the radial distance of each corner of the polygonal nut profile from the casing axis. The technical problem is a corrosion protection cap which can be clamped and detached virtually effortlessly by manual actuation and which moreover has a high pull-off force. The spring ring (10) seated in the cylindrical casing (2) has radially inwardly protruding webs (14) with said groove profiles, and the webs (14) are inclined in the radial direction toward the top wall (5) of the corrosion protection cap (1).

Abstract: A cover cap for a hexagonal recess in a screw head with an annular wall engaging in the recess. On the outer side an axial rib is provided, with the diametrical clearance between the outer edge of this rib and the diametrically opposed convex surface line of the outer side of the annular wall being greater than the flank clearance between opposing flank walls of the hexagonal recess.

Abstract: A plastic protecting cap for the clamping on a polygon nut, with a cylinder casing, which overlaps the polygon nut. The technical problem of the present invention is the provision of a plastic protecting cap, which, by a turning movement, can be clamped safely and firmly on the polygon nut and can be released therefrom by turning in opposite direction again. On the internal face of the casing, at least, two axial profile webs are arranged at places corresponding to polygonal corners, each web comprises a groove profile, open against the axis, with a vertex angle equal to the polygon angle, the radial distance of the vertex of each groove profile from the profile axis being slightly smaller than the radial distance of each corner of the polygon nut profile from the profile axis, and one flange surface of the groove profile is longer, in circumferential direction, than the other flange surface.