B-Line Eaton series Type 1 junction boxes, 18" height, 6" length, 15" width, 1, Screw cover, SC NK enclosure, Surface mounted, Medium single door, No

No. The 18156 SC NK carries a NEMA Type 1 rating, which is indoor, general purpose only. It offers no protection against rain, hose-down, dust ingress or corrosive atmospheres. For an outdoor wall or a wet mechanical room you need a Type 3R or Type 4/4X enclosure instead. Keep this one in dry indoor electrical rooms, corridors and back-of-house spaces.

18 inches high, 15 inches wide, and 6 inches deep. That 6 inch depth is what matters most on a retrofit: it gives you room for wire bending and splice devices behind the cover, but you need 6 inches of clear projection off the wall surface plus the cover screws. The box weighs 15.8 lb empty, so a single installer can set it, though anchoring into studs or masonry is still the right call.

No knockouts. The 18156 SC NK is supplied as a blank-sided screw cover enclosure, so every conduit entry gets field-punched with a knockout punch or hole saw to suit your raceway layout. That is an advantage on a custom pull or junction point since nothing is pre-opened where you do not want it, but budget the punch time and plan to seal any opening you make oversized.

It is built to UL 50, the standard covering enclosures for electrical equipment. Paired with the Type 1 rating, that is the usual combination specified for indoor general purpose junction and pull boxes in commercial and institutional buildings. The box is made in the US, which matters if your project carries domestic sourcing requirements.

Surface mount, through thru holes in the back of the box. There are no external mounting feet or flanges to work around, so the fasteners pass through the enclosure interior and land directly on your wall, strut or backboard. Supply your own anchors sized to the substrate. Mounting hardware is not part of the box.

Screw cover boxes like the 18156 SC NK suit points you rarely open: pull boxes, splice points, gutters and junctions that get terminated once and closed. The cover comes fully off, which gives unobstructed access during rough-in but means a loose panel to hold when you service it. If the box houses controls, terminal blocks or anything a technician opens routinely, choose a hinged-door Type 1 enclosure instead. One helpful touch here is the keyhole slots on the cover, so the cover can be lifted and reseated without backing every screw all the way out.

16 gauge carbon steel, finished in ANSI 61 grey paint. That is the standard grey used across most industrial control gear, so it blends with panelboards and control cabinets already on the wall. The cover screws are plated. Because it is painted carbon steel rather than stainless, keep it out of damp or chemical environments where the coating can be compromised.

The catalog number is 18156 SC NK from Eaton's B-Line series. The number reads directly off the dimensions: 18 high, 15 wide, 6 deep, SC for screw cover, NK for no knockouts. If you need the same footprint with pre-punched conduit entries, you are looking at a different suffix in the same series.