A flange nut is a type of nut that has a wide flange at one end that serves as an integrated washer. Flange nuts are made of hardened steel and coated zinc and can be used in a variety of applications, depending on the style purchased, in a hexagonal shape. The flange nut can be adjusted and removed after installation.

A flange nut, also known as a gasket nut or a spoil nut, is a nut of a special design. Its unique feature is that it is equipped with a wide flange at one end, which allows the flange nut to be used as a one-piece washer. This feature allows the flange nut to evenly distribute the pressure over the fixed component in the application, greatly reducing the risk of component damage. At the same time, due to the non-uniformity of its fastening surface, the flange nut has excellent anti-loosening properties.

It is important to note that flange nuts are used a limited number of times because the effective torque decreases with each use. Other advantages of a flange nut are that the nut works very well with reduced preload by using its remaining rotational resistance.