Anticorrosion protective cap for screw heads

摘要

The cap has an end flange (3) with a first sealing lip (9) and a second sealing lip (10) which adjoins under tension the ring edge (7) of the head (6) of the screw fitting (5). This second lip acts with the first sealing lip (9) to define a dry electrolyte-free chamber. A third sealing lip (12) adjoins a ring wall (21) of the head enclosing the operating profile (8). The cap can have a head wall (4) covering the head (6) and provided with an aperture (13) for access for a tool into the inner hexagonal recess (8). The aperture can be closed by a stopper held on a pliable band. The cap and screw can form a preassembled unit.