In order to fasten objects together using a nut, a bolt is inserted into a hole in the objects of interest. The bolt must extend out the opposite side of the objects. The nut is then placed on this end of the bolt and can be twisted to mate the internal threads of the nut with the external threads of the bolt.
The nut can then ride up the shaft of the bolt until it is flush with the objects to be fastened. Now the objects are sandwiched together between the head of the bolt and the nut, keeping them fastened to each other. To better hold objects together, a wrench can be used to tighten the nut and bolt system.
Like any other fastener, there are many different kinds of nuts to meet all of the different fastening applications. When most people think of nuts, they think of the hex nut. This is because the hex nut is the most commonly used nut. Its hexagonal shape makes it easy to grip and tighten with tools.
The locknut is another important type of nut. As its name suggests, the locknut locks into place once it is tightened. This is especially useful in applications that involve vibrations which can cause regular nuts to loosen.
Other than these two nuts there are also wing nuts, cap nuts, barrel nuts, insert nuts, square nuts, weld nuts, and flange nuts.