castellated nut

English

A typical castellated nut, with either a yellow zinc or cadmium plating.

A split pin (UK usage) / cotter pin (USA usage) installed within a castellated nut.

Etymology

Physically descriptive via a metaphor; called thus because the slots in the nut — the castellations — have a fancied resemblance to the battlements of a castle.

Noun

castellated nut (plural castellated nuts)

1. A type of nut (internally threaded fastener) with castellations, typically to hold a retaining pin that is passed through a cross-drilled hole, such as a cotter pin.

See also

• crenellation