Distorted thread locknut
An elliptical offset locknut is a nut that has been deformed at one end so that the threads no longer perfectly circular. The deformed end is usually shaped into an ellipse or obround triangle. The nut is easily started on the male fastener as the bottom portion is not deformed. As the male fastener reaches the deformed section it deforms the threads of the nut elastically back into a circle. This action increases the friction between the nut and the fastener greatly and creates the locking action. Due to the elastic nature of the deformation the nuts can be reused indefinitely.[1]
Because these nuts are solid metal, they are effective in elevated temperature settings, unlike nyloc nuts. High grade nuts are good up to 1,400 °F (760 °C). High strength elliptical offset nuts cannot be used with low strength fasteners because the hard nut will act like a die and destroy the threads on the fastener.[1]
Cleveloc, a popular brand of oval lock nut, is a registered trade name of Forest Fasteners.
References
Notes
Bibliography
- Smith, Carroll (1990), Carroll Smith's Nuts, Bolts, Fasteners, and Plumbing Handbook, MotorBooks/MBI Publishing Company, ISBN 0879384069.