A flange nut looks like a standard hex nut from one side, but the bottom is widened into a circular flange, creating a bell-like shape. Most of the time manufacturers serrate the bearing surface of flange nuts So that it gives a better grip on the surface of the joint. 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.
Flange nuts are sometimes provided with a swivel flange which helps in creating a more stable structure without affecting the finished product like a serrated flange nut.
The flange may be serrated to provide a locking action. On a serrated flange nut, the serrations are angled such that they keep the nut from rotating in the direction that would loosen the nut. Because of the serrations, they cannot be used with a washer or on surfaces that must not be scratched. The serrations help in preventing the vibration of the nut from moving the fastener, thus maintaining the holding power of the nut.
Flange nuts are widely used in automobiles, electronic products, and the aerospace industry.
CE offers these nuts mostly hexagonal in shape and are made up of hardened steel and often coated with zinc.