A flange nut is a nut that has a wide

flange A flange is a protruded ridge, lip or rim (wheel), rim, either external or internal, that serves to increase shear strength, strength (as the flange of a steel beam (structure), beam such as an I-beam or a T-beam); for easy attachment/transfer o ...

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 mostly hexagonal in shape and are made up of

hardened steel The term hardened steel is often used for a plain-carbon steel, medium or high carbon steel that has been given heat treatment and then quenching followed by tempering (metallurgy), tempering. The quenching results in the formation of metastable ma ...

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.

Self-aligning nut

A self-aligning nut, also known as a spherical nut or leveling nut, is a type of nut 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 washer. The device is commonly used in the

aerospace industry Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial, and military applications. Aerospace engineering consists of aeronautics and astr ...

. 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 edu ...

B18.2.2 *

ISO The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries. Me ...

4161 *

DIN DIN or Din or din may refer to: People and language * Din (name), people with the name * Dīn, an Arabic word with three general senses: judgment, custom, and religion from which the name originates * Dinka language (ISO 639 code: din), spoken ...

EN 1661, and the DIN 6923 which it has superseded * JIS B 1190 *

JASO The Japanese Automotive Standards Organization () is an organization that sets automotive standards in Japan, similar to the Society of Automotive Engineers (SAE) in the United States. JASO establishes standards for various types of engine oil, i ...

F 126 (used in the Japanese automotive industry)

References

{{Nuts (hardware) Nuts (hardware)

Variants

Serrated flange nut

Self-aligning nut

Standards

See also

References