This locknut secures bearings with an adapter sleeve or directly on a threaded shaft seat, providing axial fixation once tightened against the bearing face. Main dimensions follow DIN 981, with a width of 12.0 mm and a net mass of 227.0 g, giving a defined seating surface for reliable torque transfer during clamping. Used together with a matching lock washer, the KM13 nut allows controlled axial positioning and preload adjustment on the shaft, which is useful when setting internal clearance during mounting. Its standardized thread and dimensions make it suitable for maintenance replacement where the original locknut needs to be matched precisely to the shaft thread size.