U-Lock Nut

A U-lock nut is a hexagonal locknut with a nylon insert or a distorted thread. The insert or distortion grips the bolt to resist vibration.

A U-lock nut locks a bolt or stud against loosening in general engineering. It takes a bolt or stud of the same thread and class. A plain washer is often placed under the nut.

This kind of nut is often made in low carbon steel. That suits general engineering and light structural work.

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 locking element is intact and the nut runs onto a bolt with normal hand force.