left hand thread Center Lock Distorted-Thread Locknuts

Fasten counterclockwise rotating components, such a mixer's propeller. Often referred to as reversible locknuts, these thread on from both sides, eliminating the possibility of improper fastening and screw damage. Unlike nylon-insert locknuts, the middle threads' uneven form provides a firmer grip on the screw. The threads make installation and removal more difficult, but they also keep the nut from backing out from vibration. You might require specialized equipment, such an impact wrench or propane torch, to remove these nuts. Nuts cannot be reused.