Extension nut Coupling Nut Hex Nut,a fastener coupling nut is a type of nut used to join two threaded rods or bolts together. It is a cylindrical-shaped nut with internal threads on both ends that allow it to be screwed onto the threads of two separate rods or bolts. Once the coupling nut is screwed onto the threads of each rod or bolt, the two rods or bolts become joined together, creating a longer threaded fastener.

Fastener coupling nuts are commonly used in applications where a longer threaded fastener is needed, but a single threaded rod or bolt is not available in the desired length. They are also used in situations where two separate threaded rods or bolts need to be joined together for added strength or stability.

Coupling nuts come in various sizes and materials, such as steel, stainless steel, brass, and nylon. The choice of material depends on the application and the environmental conditions the nut will be exposed to.

A fastener coupling nut is typically used to join two threaded rods or bolts together. These nuts are often used in applications where a longer bolt or rod is needed, but a single, long piece is not available.

Coupling nuts can also be used to extend the length of an existing bolt or rod, or to connect two threaded components that are different sizes or have different thread types. In addition, they can be used in applications where disassembly may be required, such as in a temporary structure or for maintenance purposes.