Steel City 52171 CV1/2 3/4 Outlet Boxes

It's a 4 x 4 x 2-1/8 inch square steel box with 30.3 cubic inches of capacity. That's the deep 4-square size, and 30.3 cubic inches is what you work against when you do your box fill calculation for conductors, devices and clamps. Shape is square, so it takes standard 4-square covers and mud rings.

It mounts to a wall or ceiling surface, and there are 17 knockouts across the sides and back for conduit and cable entries. That knockout count is why electricians use the deep 4-square as a junction point as well as a device box: you can bring several raceways in and still have room to splice inside 30.3 cubic inches.

No. The Steel City 52171 CV1/2 3/4 is a 4 inch square steel box carrying a weatherproof rating of N, so it belongs in dry interior work. For an exposed exterior device, the Mulberry Royal Mountie weatherproof outlet box is a die-cast aluminum 1-gang box built for that duty, and the Thomas and Betts 2IH3-1 Red-Dot is a 2-gang conduit outlet box with three 1/2 inch hubs for surface conduit runs outside.

The 52171 CV1/2 3/4 is a standard steel outlet box listed to UL E2969 and is not an explosionproof enclosure. For classified locations the Appleton GRJ series explosionproof conduit outlet box and the Appleton GRJS universal explosionproof box are malleable iron bodies made for that service, and the Appleton GRT75 is a malleable iron round conduit outlet box in the same family of fittings.

Steel, finished silver. A steel box is conductive, so it becomes part of the equipment grounding path when you land metallic conduit or an armored cable connector on it, which is the usual reason it gets specified over a nonmetallic box like the Cantex EZ Series PVC box.

Each box weighs about 1 lb and ships 25 to the outer carton, so a full case gives you 25 boxes. Good to know if you're stocking a van or a job trailer rather than buying onesies.