2 Gang 35mm Dual Galvanised Steel Back Box

The Knightsbridge 2-gang 35mm dual galvanised steel back box is designed for mounting two single-gang wiring accessory plates side by side in a 1G + 1G configuration. Pressed from 1mm galvanised steel with a tolerance of +/- 1%, the box provides a rigid mounting frame for switches, sockets or data faceplates where a double-gang plate cannot be used due to spacing or circuit requirements.

This box is used in residential, commercial and industrial installations where two separate circuits or accessories need to be mounted adjacently on the same wall — for example, a light switch next to a socket, or two sockets on different ring mains. The 35mm recessed depth suits standard plasterboard and dot-and-dab installations, while the 158mm overall width accommodates two 86 x 86mm plates with a small gap between them. Six fixed mounting lugs and two adjustable lugs provide multiple fixing points for horizontal or vertical mounting, and earth terminals on the box ensure safe earthing of metal faceplates.

The galvanised finish resists corrosion in damp or humid environments, making the box suitable for kitchens, utility rooms, garages and light commercial settings. Pre-punched 20mm knockouts on multiple faces allow cable entry from different directions, and the box complies with EN 60670 standards for UK electrical installations. The 1mm steel gauge provides structural rigidity without adding excessive depth to the wall recess.

Product Specification Sheet

What's the difference between a dual box and a 2-gang box?

A dual box mounts two separate single-gang plates side by side (1G + 1G), whereas a 2-gang box mounts one double-width 2-gang plate. Dual boxes are used when two circuits need to be kept separate or when mixing different accessory types in adjacent positions.

What depth of plasterboard or wall is needed?

The 35mm recessed depth is designed for standard 12.5mm plasterboard on timber studs or 15mm dot-and-dab plasterboard on brick/block walls. The box sits flush with the wall surface once the plaster or plasterboard is in place.

Can this box be chased into solid walls?

Yes. The box can be chased into brick, block or concrete walls provided the chase is cut to the correct dimensions (73mm height x 158mm width x 35mm depth) and the box is secured with screws or plaster.

What size plates does it take?

The box accepts two standard 86 x 86mm single-gang plates mounted side by side. It is not compatible with double-gang plates or non-standard plate sizes.