Thomas & Betts XJG104-EMT EMT Expansion Coupling, 4 In, 4 In Travel

The XJG104-EMT is a 4 inch EMT expansion coupling, so it goes on 4 inch electrical metallic tubing. It is not a fitting for rigid or IMC threaded conduit, and it will not take any other trade size.

It is built for 4 inches of travel. That is the total movement the coupling absorbs as the run expands and contracts, which is what you want where a 4 inch EMT run crosses a building expansion joint or a long exterior run that sees a wide temperature swing.

A standard coupling ties two lengths of EMT together rigidly. An expansion coupling like the XJG104-EMT lets the conduit slide as it moves, so use it wherever the run crosses a structural expansion joint or where thermal movement would otherwise buckle the conduit or pull it out of a box. Everywhere else on the run, a standard 4 inch EMT coupling is the right part.

XJG104-EMT is the part number, a Thomas & Betts 4 inch EMT expansion coupling rated for 4 inches of travel. The XJG series prefix with the -EMT suffix is what separates it from the threaded-conduit versions, so quote the full designation including the suffix when ordering.

Ductile iron. That is a cast body rather than a stamped steel one, which is why these expansion fittings hold up on large trade sizes and in exposed runs where the conduit is carrying real weight and moving against the fitting.