A flange nut is a nut that has a wide flange at one end that acts as an integrated washer. This serves to distribute the pressure of the nut over the part being secured, reducing the chance of damage to the part and making it less likely to loosen as a result of an uneven fastening surface. These nuts are hexagonal in shape and are made up of hardened steel and can be coated with zinc. The flange may be serrated to provide a locking action.
