spring washers

spring washers are used to prevent an unintentional loosening of a screw connection.

The spring washer is cut open at one point and is placed between the nut/screw head and the contact surface of the component. The cut edges are not deburred and thus drill into the contact surface of the nut/screw head and the component. When loosened, the burr tips act as barbs and thus prevent the screw connection from loosening.