A flange nut is a

nut Nut often refers to: * Nut (fruit), fruit composed of a hard shell and a seed, or a collective noun for dry and edible fruits or seeds * Nut (hardware), fastener used with a bolt Nut or Nuts may also refer to: Arts, entertainment, and media Co ...

that has a wide

flange A flange is a protruded ridge, lip or rim, either external or internal, that serves to increase strength (as the flange of an iron beam such as an I-beam or a T-beam); for easy attachment/transfer of contact force with another object (as the f ...

at one end that acts as an integrated

washer Washer most commonly refers to: *Washer (hardware), a thin usually disc-shaped plate with a hole in the middle typically used with a bolt or nut *Washing machine, for cleaning clothes Washer may also refer to: *Dishwasher, a machine for cleani ...

. 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 mostly hexagonal in shape and are made up of

hardened steel The term hardened steel is often used for a medium or high carbon steel that has been given heat treatment and then quenching followed by tempering. The quenching results in the formation of metastable martensite, the fraction of which is reduced ...

and often coated with zinc. Flange nuts (and bolts) are widely used in automobiles and electronic products.

Variants

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.

Swivelling flange nut

Flange nuts are sometimes provided with a swivel flange which helps in creating a more stable structure without affecting finished product like a serrated flange nut. Swivel flange nuts are mostly used in joining wood and plastic.

Self-aligning nut

A self-aligning nut, also known as a spherical nut or leveling nut, is a type of

used in applications where the fastener is not perpendicular to the surface to which the nut anchors. A flange nut is used inside a specially shaped dished-out

. The device is commonly used in the aerospace industry. If this nut were not used the object would have to be spot faced so as to provide a surface perpendicular to the fastener.

Standards

The following specifications define flange nuts: *

ASME The American Society of Mechanical Engineers (ASME) is an American professional association that, in its own words, "promotes the art, science, and practice of multidisciplinary engineering and allied sciences around the globe" via "continuing ...

B18.2.2 *

ISO ISO is the most common abbreviation for the International Organization for Standardization. ISO or Iso may also refer to: Business and finance * Iso (supermarket), a chain of Danish supermarkets incorporated into the SuperBest chain in 2007 * Iso ...

4161 * DIN EN 1661, and the DIN 6923 which it has superseded * JIS B 1190 * JASO F 126 (used in the Japanese automotive industry)

References