Slotted Nut

A slotted nut is a locknut with slots cut across the top. It uses a split pin or cotter pin through the slots to stop the nut turning.

A slotted nut locks a mating bolt or stud against vibration. It takes a cotter pin or split pin through the slots and a matching hole in the bolt. A nut of the same thread and class is often matched with a plain washer.

This kind of nut is often made in low carbon steel. That suits light duty joints where high strength is not needed.

This is a general guide to checking this kind of part. It says nothing about any supplier's parts.

Ask for a certificate of conformance with the grade and thread size. On receipt, check the slots are clear, the thread runs freely, and the nut spins onto a matching bolt by hand.