Hex Lock Nut

A hex lock nut is a six-sided nut with a locking element, such as a nylon insert or a deformed thread, to prevent loosening. It is used where vibration or movement could undo a standard nut.

A hex lock nut clamps a joint where vibration can loosen a plain nut. It takes a bolt or stud of the same thread and class, and often a washer under the nut. A spanner or socket sets it.

Hot-dipped galvanised finish gives a thick zinc coating for outdoor or corrosive environments. Plain finish has no coating. PTFE-coated finish adds a low-friction layer that can ease tightening and resist chemicals.

Hex lock nuts are often made in steel, stainless steel, or brass. Stainless steel grades such as 304 and 316 are chosen for corrosion resistance. Steel grades can be heat treated for higher strength.

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 that lists the material, dimensions and locking torque. On receipt, check the thread, locking element and finish for damage.