Abstract: A lock nut having a locking ring with a spoon-shaped lug. The lock ring includes a nut body having a bore with an interior threaded portion and a substantially cylindrical recess coaxial with the threaded portion of the bore. The recess includes a single notch on a portion of the recess. In addition, the lock ring includes a threaded locking ring positioned within the recess. The locking ring is deformed when threading the bolt onto the lock nut to frictionally grip the bolt. The locking ring also includes a single projecting lug at one side only of the locking ring, which fits into the notch to prevent relative rotation between the ring and the nut body. The lug includes a bowl-shaped nodule for collecting shavings gathering within the threads of the bolt and the interior bore of the lock nut.