what is a self locking nut used for?

A self-locking nut, also known as a lock nut, is a type of nut that is designed to resist loosening under vibrations and torque. It has a locking action that prevents it from coming loose. Self-locking nuts typically have a portion that deforms elastically to provide the locking action .

There are various types of self-locking nuts available, including nyloc nuts, which have a nylon collar insert that resists turning and locks the nut in place ; all-metal self-locking nuts, which do not require extra torque until seated and other specialized lock nuts such as castellated nuts, distorted thread locknuts, interfering thread nuts, jam nuts, and more .

Self-locking nuts are commonly used in applications where there is a risk of loosening due to vibrations or torque. They are used in various industries, including automotive, construction, rail and traffic, energy, and shipbuilding, among others These nuts provide a secure fastening solution and help maintain joint integrity in different assemblies .

Please note that the specific type of self-locking nut used will depend on the application requirements and the environment in which it will be used .