Elemento de fijación

摘要

The washer (1) has flat projections (13) formed at a side, where each of the projections has a multi-edged circumference i.e. rectangular circumference. The projections are arranged at an angle to a surface of the washer such that wedge-shaped projections are formed. The projections are aligned to the washer such that projected wedge ends point in a rotation direction of the washer. A circular collar (12) is formed opposite to the projections for enclosing a circular flange formed at a lower side of a bolt (2), where the washer is undetachably fastened at the flange.