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3 Gang 35mm Triple Galvanised Steel Back Box

£199
The RRP is the manufacturer's recommended retail price of the item.
Limited Stock
We are an Independent UK Company
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Minimum order for this item is 5.

Description

The Knightsbridge 3-gang 35mm galvanised steel back box mounts three separate 1-gang wiring accessory plates side by side in a single continuous wall aperture. The box measures 244mm wide by 73mm high, with a 35mm recessed depth behind the wall surface, and is constructed from 1mm-thickness galvanised steel to EN 60670 standards.

Designed for residential and commercial installations where three separate switches, sockets or data plates need to be grouped together, the box accepts standard 86 x 86mm faceplates only. Six fixed mounting lugs provide screw-fixing points for the cover plates, while earth terminals on the back plate ensure continuity across all three outlets. Pre-formed 20mm knockouts on the sides and base allow cable entry from multiple directions without drilling.

The galvanised steel construction resists corrosion in plasterboard and brick cavity walls, and the 35mm depth accommodates standard switch mechanisms and socket terminals without requiring deeper recessing. The box ships bulk-packed in shrink-wrapped Knightsbridge trays, with a 25-year warranty covering material defects and construction failures.

Specification
Height 73 mm
Width 244 mm
Recessed Depth 35 mm
Construction Steel
Earth Terminal Yes
Warranty 25
Downloads

Product Specification Sheet

Frequently Asked

What plates does this box accept?

The box is designed for standard 86 x 86mm wiring accessory plates only. It will not accept larger grid plates or non-standard sizes. Each of the three positions accepts one 1-gang plate, giving configurations such as three separate light switches or a socket plus two data plates.

What depth of wall cavity is needed?

A minimum 35mm cavity depth is required to recess the box flush with the wall surface. On stud walls with 50mm studs or deeper brick walls this poses no issue, but shallow partition walls may need to be checked before cutting the aperture.

Are the knockouts removable?

Yes. The 20mm knockouts are pre-formed but not removed during manufacture. They can be punched out with a screwdriver or knockout tool during installation to allow cable entry. Any unused knockouts should remain in place to maintain the box integrity.

Does the box include fixing screws?

No. Wall fixings and screws are not included and must be sourced separately depending on the wall construction. The six mounting lugs on the box are threaded to accept M3.5 screws for attaching the cover plates.

Shipping & Returns

Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

To arrange a return, call us on 020 8149 5199 or use our contact page.

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Over 20 years lighting homes worldwide

We are a specialist lighting and mirror retailer with showrooms in Birmingham, Hong Kong and Dubai, shipping to customers around the world. Our own design team is here to help, from first idea to final fitting.

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Every product arrives brand new with the full manufacturer warranty. Found it cheaper elsewhere? Ask us about a price match.

Installation

Fits standard UK back boxes

Designed to fit standard UK back boxes for a straightforward swap of your existing fittings.

Ordering with us

Free delivery over £99

Free delivery on orders over £99, in the UK and worldwide. Easy returns within 14 days, subject to our returns policy. Full manufacturer warranty included.

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    Description

    The Knightsbridge 3-gang 35mm galvanised steel back box mounts three separate 1-gang wiring accessory plates side by side in a single continuous wall aperture. The box measures 244mm wide by 73mm high, with a 35mm recessed depth behind the wall surface, and is constructed from 1mm-thickness galvanised steel to EN 60670 standards.

    Designed for residential and commercial installations where three separate switches, sockets or data plates need to be grouped together, the box accepts standard 86 x 86mm faceplates only. Six fixed mounting lugs provide screw-fixing points for the cover plates, while earth terminals on the back plate ensure continuity across all three outlets. Pre-formed 20mm knockouts on the sides and base allow cable entry from multiple directions without drilling.

    The galvanised steel construction resists corrosion in plasterboard and brick cavity walls, and the 35mm depth accommodates standard switch mechanisms and socket terminals without requiring deeper recessing. The box ships bulk-packed in shrink-wrapped Knightsbridge trays, with a 25-year warranty covering material defects and construction failures.

    Specification
    Height 73 mm
    Width 244 mm
    Recessed Depth 35 mm
    Construction Steel
    Earth Terminal Yes
    Warranty 25
    Downloads

    Product Specification Sheet

    Frequently Asked

    What plates does this box accept?

    The box is designed for standard 86 x 86mm wiring accessory plates only. It will not accept larger grid plates or non-standard sizes. Each of the three positions accepts one 1-gang plate, giving configurations such as three separate light switches or a socket plus two data plates.

    What depth of wall cavity is needed?

    A minimum 35mm cavity depth is required to recess the box flush with the wall surface. On stud walls with 50mm studs or deeper brick walls this poses no issue, but shallow partition walls may need to be checked before cutting the aperture.

    Are the knockouts removable?

    Yes. The 20mm knockouts are pre-formed but not removed during manufacture. They can be punched out with a screwdriver or knockout tool during installation to allow cable entry. Any unused knockouts should remain in place to maintain the box integrity.

    Does the box include fixing screws?

    No. Wall fixings and screws are not included and must be sourced separately depending on the wall construction. The six mounting lugs on the box are threaded to accept M3.5 screws for attaching the cover plates.

    Shipping & Returns

    Delivery UK delivery is £14.99, and delivery is free on all orders of £99 or more, in the UK and internationally.

    Returns If you change your mind, you have 14 days from delivery to tell us, and a further 14 days to send the goods back. Return postage for a change-of-mind return is paid by you. Change-of-mind returns are subject to an inspection and handling deduction. See our full returns policy.

    To arrange a return, call us on 020 8149 5199 or use our contact page.