Securlec Metal Back Box 1 Gang

Securlec Metal Back Box – 1 Gang, Flush Mount, Galvanised Steel (16mm, 25mm, 35mm, 47mm Depths)

Durable Flush-Mount Enclosures for Safe, Secure Electrical Installations in Masonry Walls

The Securlec 1 Gang Metal Back Box is designed to provide a robust and reliable foundation for flush-mounted electrical accessories such as switches, sockets, and data points. Engineered to meet BS EN 60670-1 standards, each back box in the range features a strong welded galvanized steel construction, ensuring durability, rigidity, and a long service life even in demanding environments.

Available in a range of depths (16mm, 25mm, 35mm, and 47mm), these back boxes are suited for a wide variety of electrical applications within internal masonry walls. With standard M3.5 mounting screws, universal knockout entries, and industry-standard dimensions, Securlec metal back boxes ensure a straightforward, code-compliant installation process for both professional electricians and competent DIY users.

Whether you're rewiring a property or installing new circuits, the Securlec Metal Back Box range delivers strength, safety, and compatibility across all common 1-gang flush-mounted electrical fittings.

Available Depths and Specifications

All models conform to:
BS EN 60670-1 – Electrical boxes and enclosures for electrical accessories for household and similar fixed electrical installations.

Key Features

Robust Welded Construction
Each back box is manufactured with fully welded joints for extra strength and durability, ensuring secure mounting of outlets and resistance to mechanical damage during plastering or cabling.

Flush Mounting for Internal Masonry Walls
Designed specifically for use in solid wall installations, these boxes sit flush with the finished plaster or tile, allowing sockets or switches to be mounted seamlessly and safely.

Pre-formed Knockouts
Each box includes 20mm or 20/25mm knockouts for conduit or cable gland entry, enabling clean, secure cable routing. The knockout design supports fast on-site installation with minimal tool use.

Universal Compatibility
Suitable for all standard 1-gang UK faceplates, including light switches, single sockets, fused spurs, and smart modules. The consistent 73mm x 73mm face ensures a reliable fit with most electrical accessories.

Corrosion-Resistant Galvanised Steel
The zinc-coated finish helps protect the box from corrosion over time, especially during the plastering and construction process.

Standardised Mounting Points
Each back box includes two M3.5 tapped lugs for mounting faceplates, ensuring easy alignment and secure fixing.

Use Case Applications

Securlec 1 Gang Metal Back Boxes are widely used in:

Residential Installations: Light switches, plug sockets, cooker switches, USB outlets

Commercial Buildings: Office wiring, data and comms points, thermostats

Renovation & Rewiring Projects: Upgrade or replace outdated or plastic back boxes

Smart Home Integration: Mounting smart switches, dimmers, and smart outlets

Workshops & Garages: Secure, heavy-duty installation of industrial-grade sockets

Depth selection guidance:

16mm: Ideal for shallow walls or slim profile accessories (e.g., data or lighting control)

25mm: Standard for most switches and sockets

35mm: Recommended for deep sockets, USB outlets, or additional wiring space

47mm: Suitable for bulky modules, dimmer switches, or where extra wiring space is required

Installation Tips

Fix Level and Flush: Ensure the box is seated square and flush with the wall surface before plastering or tiling. Use a spirit level for alignment.

Knockouts: Tap knockouts from inside the box using a screwdriver and hammer. Fit grommets or bushes as required to protect cabling.

Secure Fixing: Use screws and wall plugs suitable for masonry. Do not overtighten.

Plaster Depth: For accurate faceplate fitting, allow for box depth when plastering or tiling over.

Care & Maintenance

Store boxes in a dry environment to avoid moisture exposure before installation

Do not use damaged or distorted boxes

Check knockout edges for burrs after removal

Use with appropriate cable grommets to comply with wiring regulations

Always use the correct tools and fittings during installation

Frequently Asked Questions (FAQ)

Q1: Are these boxes suitable for plasterboard walls?
A: No. These are designed for flush fitting into masonry walls. For plasterboard or dry walls, use surface-mounted or drywall (cavity) boxes.

Q2: Can I use them with metal conduit?
A: Yes. The 20mm and 25mm knockouts are compatible with standard metal conduit and gland fittings.

Q3: What is the difference between gang and depth?
A: Gang refers to the number of switch/socket modules (1 gang = single switch/socket). Depth determines how much space is available for wiring behind the accessory.

Q4: Is galvanised steel safe for electrical use?
A: Yes. It provides strong mechanical protection and resists corrosion. It’s the standard material for metal electrical back boxes in the UK.

Q5: Can these be used in bathrooms?
A: These boxes can be used behind bathroom-rated accessories, provided all work follows Part P electrical safety regulations and suitable ingress protection is maintained.

Why Choose Securlec Metal Back Boxes?

Built to exacting standards and trusted by professionals, Securlec Metal Back Boxes provide the strength, safety, and reliability required for compliant electrical installations. Whether you're upgrading, rewiring, or building new, this range offers dependable performance across a wide spectrum of applications – from basic domestic wiring to high-spec commercial setups.

Engineered for safety. Designed to last.