The spring washers M4, DIN 127 B, also called spring washers, locking washers or locking rings, are locking elements that are used as a simple screw locking device against loosening. The installation is optimally carried out between the screw head or a nut and a washer. Due to the curved shape, a certain pretension is created on the connection, vibrations are intercepted and independent loosening is prevented. Quantity: 50 pieces