Locknut KM19 secures bearings and other components onto a shaft by clamping against a locking washer, transmitting axial load through the threaded connection while preventing unintentional loosening under operation. Main dimensions comply with DIN 981, giving a width of 17.0 mm and a net mass of 0.673 kg, allowing straightforward interchange with other locknuts built to the same standard. The nut is fitted onto the threaded section of a shaft and tightened against the bearing inner ring, with axial position set by turning it into place; a compatible locking washer is required to lock rotation once the assembly is torqued. This design suits applications where a shaft assembly needs precise axial positioning and a means of retaining that position against vibration or shaft rotation, and where dimensional compliance with DIN 981 is needed for compatibility with the mating bearing and shaft geometry.