Hex Jam Nut

A hex jam nut is a thin nut with a hexagonal shape. It is often used to lock another nut in place or to adjust and secure a threaded rod.

A hex jam nut is thinner than a standard hex nut and locks against another nut or a surface. It takes a spanner of the matching size and pairs with a bolt or stud of the same thread. Two jam nuts can be locked against each other on a stud.

This kind of nut is often made in stainless steel or steel. Stainless steel grades such as 304 and 316 give good corrosion resistance. Steel can be used in dry conditions or with a coating.

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 or a mill test certificate if you need to verify the material. On receipt, check the nut for correct thread size and thickness. Look for damage such as cracks or damaged threads.