Flangelike toothed security plate

摘要

The safety washer for preventing rotation of a screw head (1) having N1 faces comprises a plate (10) having a hole (11) whose perimeter has N2 notches per side of the external screw head. It is arranged so that the notches engage six dihedrals (7) of the screw head. The plate is mounted on the body (3) in a position chosen from among N3 possible positions, where N3 is a prime number. The fixing of the plate onto the body allows an angular play of the plate around the screw head axis. This added angular play between the notches and the screw head is greater than 360o divided by the product N1xN2xN3.