A round coupling nut is a type of fastener that is primarily used to connect two pieces of threaded rod or other fasteners together. Unlike standard nuts, which have a hexagonal shape, round coupling nuts have a cylindrical design. This feature allows for easier handling and, in some applications, provides aesthetic benefits as well.
Less bulky than hex coupling nuts, these have a smooth, round body that fits in tight spots. Their finished appearance makes them a common choice for decorative applications. Tighten by hand, or use soft-jaw pliers to avoid marring the outside surface. Also known as extension nuts, they are commonly used to connect lengths of threaded rod and join threaded parts.
There are many industries that use these fasteners, but they are especially useful in applications where pipes or rods must be elongated and still maintain strength at the connection point. This is often the case in plumbing, custom manufacturing, construction, and instances where traditional fasteners - like a screw - don't offer enough of a secure connection.
The most important measurements on a coupling nut are:
Overall Length: The length of the nut
Round Size: outter diameter
TPI (Threads Per Inch) or pitch : The number of threads present in an inch of the thread length or the distance of two thread.
Thread type: UNC /BSW /MM/Metic
