Steel City 52151 MS N Steel Square Outlet Box, 4 In, 21 Cu In

It's a 4 inch square steel box measuring 4 inches height x 4 inches width x 1-1/2 inches depth, with 21 cubic inches of volume. That 21 cu in is the number you use for conductor fill calculations, and it's the standard shallow 4-square depth, so it will go into a 2x4 stud bay without furring.

Eleven knockouts, in combination 1/2 and 3/4 inch trade sizes, so you can run either EMT/connector size into the same box without an adapter.

No. The 52151 MS N is a plain galvanized steel interior outlet box with open knockouts, not a weatherproof enclosure. For an exposed exterior device, use a weatherproof box like the Mulberry Royal Mountie die-cast aluminum 1-gang, or a Red-Dot threaded-hub box such as the Thomas and Betts 2IH3-1 with three 1/2 inch hubs.

No. The 52151 MS N is a knockout-style steel square box with eleven knockouts, listed under UL E2969 for general use. Classified areas call for an explosionproof enclosure such as the Appleton GRJ Series or GRJS Series malleable iron conduit outlet boxes, or the Appleton GRT75 malleable iron round conduit outlet box, all of which are threaded malleable iron bodies rather than knockout sheet steel.

The 52151 MS N is a 4 inch square steel box, 1-1/2 inches deep, 21 cubic inches, intended for dry interior work. For an exterior or wet location on a single device, the Mulberry Royal Mountie weatherproof outlet box is a die-cast aluminum 1-gang box built for that exposure. Note the Royal Mountie is a 1-gang device box rather than a 4 inch square, so device rings and covers are not interchangeable with the Steel City box.

The 52151 MS N is the nonmetallic version of the 4 square box, intended for NM cable runs rather than raceway clamping. It has no internal conduit clamps; the 1/2 and 3/4 inch knockouts take the NM connector or cable clamp you supply.

The 52151 MS N is steel, which is what most commercial and multi-family specs call for and what you want if the EGC path runs through the enclosure. For straight residential work where a nonmetallic box is acceptable, the Cantex EZ Series PVC multi-gang residential box is the alternative. A 4 square steel box also needs a cover or mud ring to finish the device, which the PVC gang box does not.

Yes. The 52151 MS N body is steel. If the job calls for a nonmetallic box, the Cantex EZ Box series is a PVC multi-gang residential outlet box. The two differ in more than material: the Steel City unit is a 4 inch square box that takes a device ring, while the Cantex EZ is a multi-gang device box, so gang count and cover selection are decided differently.

The 52151 MS N is a 4 inch square, 1-1/2 inch deep steel box with eleven knockouts sized for 1/2 and 3/4 inch connectors, so raceway entries are made where you open a knockout. The Thomas and Betts 2IH3-1 Red-Dot box is a 2-gang conduit outlet box with three fixed 1/2 inch hubs, supplied in a pack of 100, so the entry locations and count are set by the casting rather than chosen in the field.

A 21 cu in 4 square is tight for heavy range or dryer conductors. For that application a purpose-built unit like the Pass and Seymour P242RRD range and dryer box is the straightforward choice.

The Appleton GRT75 is a malleable iron round conduit outlet box, making it the round threaded-body option where the 52151 MS N is a square knockout steel box measuring 4 by 4 by 1-1/2 inches. The Appleton GRJS Series is described as a universal conduit outlet box if you need one body to cover multiple entry configurations.