Steel City 52171MSX Outlet Box with MS Arm Bracket

The box holds 30.3 cubic inches, which is what you work your conductor fill against under the box-fill rules for the wire size you're pulling. It's a standard 4 inch square steel box, so if you need more room than 30.3 cubic inches you're looking at a deeper 4-square or an added extension ring rather than this one.

Pigtail. The 52171 MSX ships without a pigtail; the 52171MSXP comes with one, so the fixture or device connection is already made up and you just splice to the branch circuit. Pick the pigtail version where you want the lead pre-installed, the plain version where you'll land conductors yourself.

The Steel City 52171MSX is a steel 4-inch square outlet box with an MS arm bracket, built for dry interior framing work. For an exposed exterior location, the Mulberry Royal Mountie weatherproof outlet box is a die-cast aluminum 1-gang box, and the Thomas & Betts 2IH3-1 Red-Dot is a 2-gang conduit outlet box with three 1/2-inch hubs for threaded conduit runs. Both are made for surface mounting to a wall or conduit rather than nailing to a stud.

No. The Steel City 52171MSX is a standard steel 4-inch square outlet box for ordinary locations. Classified areas call for an explosionproof box such as the Appleton GRJ series or GRJS universal conduit outlet box in malleable iron, or the Appleton GRT75 malleable iron round conduit outlet box. Those use threaded conduit entries and a sealed cover rather than knockouts and a bracket.

The MS arm bracket is a mounting arm welded to the box so it fastens to the face of a stud and sets the box at the right depth for the finished wall, instead of being nailed or screwed through the side. It saves setting the box by eye on wood framing, which is why it shows up on rough-in work where a lot of boxes go in fast.

A steel 4-square like the 52171MSX bonds through the box itself and takes conduit, armored cable, or clamped NM, and the welded MS arm bracket indexes it off the stud face. A nonmetallic alternative such as the Cantex EZ Series PVC multi-gang residential box needs no bonding to the enclosure and is lighter, but it won't take a metal raceway termination. Metal raceway or a metal fixture support usually decides it for steel.

The Steel City 52171MSX is a general purpose 4-inch square steel box with 30.3 cubic inches of volume and a bracket for framing. For a dedicated 240-volt appliance outlet, the Pass and Seymour P242RRD is a thermoplastic range and dryer box, built around that specific receptacle rather than a standard device or cover plate.

Yes. The Steel City 52171MSX body is steel, which is what lets the box bond through the raceway and accept metal clad or conduit wiring methods. If a nonmetallic box suits the job, the Cantex EZ Box is a PVC multi-gang residential outlet box. Being PVC, it offers no metallic bonding path, so an equipment grounding conductor has to be carried through to the devices.

The Steel City 52171MSX is a steel 4-inch square box with knockouts and an MS arm bracket, so it fastens to a stud or joist and takes cable or conduit through a knockout. The Thomas and Betts 2IH3-1 Red-Dot is a 2-gang conduit outlet box with three 1/2-inch threaded hubs, intended to land directly on a conduit run; it is sold in packs of 100, while the 52171MSX is sold each.

It's sold each, so you can order the exact count for a job rather than a carton quantity. For contrast, the Red-Dot 2IH3-1 conduit box is packed 100 to a box.

The Steel City 52171MSX is a single 4-inch square steel box; multiple devices in it require a 2-gang mud ring or cover. If you want a box built as multi-gang from the start, the Cantex EZ Box is a PVC multi-gang residential outlet box, and the Thomas and Betts 2IH3-1 Red-Dot is a 2-gang conduit outlet box with three 1/2-inch hubs.