Abstract: A locknut including a nut member having an internal thread extending throughout its length, a key-receiving configuration on the outer end of the nut member in radial overlapping relationship with a portion of the internal thread, a shroud rotatably mounted on the nut member and having an annular end which is in radial overlapping relationship with the key-receiving configuration, an internal flange on the shroud, an external groove in the nut member for receiving the internal flange to permit relative rotation between the nut member and the shroud while preventing separation therebetween, a cam surface on the nut member over which the internal flange travels to be positioned within the external groove on the nut member, an external flange on the nut member, and an internal shoulder on the shroud for engagement by the external flange to permit the nut member to rotate relative to the shroud while the external flange is in engagement with the internal shoulder.