Coupling Nut

A coupling nut is a long hexagonal nut used to join two threaded rods or studs end to end. It usually has internal threads running through its full length.

A coupling nut joins two threaded rods or studs end to end. It takes two lengths of threaded rod of the same thread and class, and it is turned with a spanner.

Hot-dip galvanising gives a thick zinc coating for outdoor and wet service. Plain finish is bare metal with no coating. PTFE coating is a low-friction layer that helps with assembly and resists chemicals.

Coupling nuts are often made in steel, stainless steel 304, stainless steel 316, or brass. Stainless steel grades resist corrosion, while steel grades suit higher strength needs.

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

Ask for a mill test certificate or a certificate of conformance to confirm the grade and material. On receipt, check the thread, the length, and that the nut runs freely on a matching rod.