EMT that separates at the coupling under flex or temperature change creates a code violation and a service call. This 1/2" EMT coupling with set screw holds the conduit rigid through the full run — the set screw compresses against the EMT wall and doesn't let go when things flex or cycle thermally. Zinc-plated for indoor/outdoor durability. The 1/2" size is the most common in residential and light commercial. Electricians across northeast Nebraska and northwest Iowa use these because they don't fail after installation. In stock at Crofton Lumber (Crofton, NE) and Akron Lumber (Akron, IA) — ready for pickup today. Stocked at Crofton Lumber and Akron Lumber.