Nut fasteners

A nyloc nut, also known nylon insert lock nut, polymer insert lock nut or elastic stop nut (although incorrectly, as an elastic stop nut is broad class of locking nuts), is a kind of nut that includes a nylon collar insert. The insert is placed at the end of the nut and its inner diameter (ID) is slightly smaller than the major diameter of the screw.
The insert deforms over the threads of the screw, but threads are not cut into the nylon. The nylon insert locks the nut in two ways. First, it forces the bottom face of the screw threads against the top face of the nut threads, increase the friction between the two. Second, the nylon applies a compressive force against the screw itself.
Nyloc nuts retain their locking ability up to 250 °F (121 °C). The threads of the screw do not damage the nylon insert, therefore they can be reused many times.nut is a registered trade name of Forest Fasteners.
The name "Nyloc" has become a genericized trademark in Australia, referring to all types and brands of polymer insert locking nuts.