This locknut secures bearings and associated components on a shaft by threading against an adjacent locking washer, providing axial fixation once tightened against the bearing face. Main dimensions follow DIN 981, with a width of 11.0 mm and a net mass of 158.0 g. The design suits applications requiring a positive axial lock on a threaded shaft seat, allowing the bearing to be clamped securely in position and preventing unintended displacement along the shaft during operation. It is used together with a matching locking washer to transmit torque reaction and maintain the set axial position over time.