Electrical Metal Back Boxes

The electrical metal back box is the unsung workhorse of any first-fix electrical installation. Every socket, switch, and faceplate needs something to sit in, and these steel back boxes do exactly that job without fuss. Available in 1 gang and 2 gang configurations across 25mm, 35mm and 47mm depths, there is a size here for almost every situation you will run into on a standard domestic or commercial job.

Depth matters more than people sometimes give it credit for. A 25mm back box is fine for a basic socket in a clear wall, but once you are routing twin and earth through conduit knockouts, or the sparky wants extra slack for a thermostat back plate, you will want the 35mm or 47mm option. The deeper the box, the more room you have to fold cable neatly without forcing a faceplate off the wall.

Where Electrical Metal Back Boxes Get Used

These are standard steel back boxes used across residential new builds, refurbishment projects, commercial fit-outs and light industrial work. The 1 gang suits single sockets and single switches, while the 2 gang covers double sockets, dual switches and combination plates. That covers a very wide percentage of everyday electrical first-fix work right there.

The knockout pattern follows the standard UK layout, so they are compatible with the usual range of faceplates from the main switch and socket manufacturers. Earthing lug is included as standard, which keeps things compliant without any additional faff.

Plasterboard, Block and Brick Fixing

For solid walls, you are cutting, chasing and screwing directly into the wall. For plasterboard dry lining, a cavity fixing or a dry lining box is typically the preferred route, though metal back boxes can still be used where the board is backed. Worth checking your fixing method suits the substrate before committing to a depth.

At this price point, buying a mixed selection of depths makes sense on any job. Running out of 35mm boxes and having to swap to a deeper box mid-job is one of those small irritations that a bit of forward planning sidesteps entirely.