Depending on the width and gang configuration, the box can use one or more center support bars. Together with pre-punched knockouts for cable and conduit entry, this structure provides a practical solution for switch and socket installations that need a firmer box body without moving to a deeper box.
Key Features
Fixed Center Support Bar
A formed metal support bar bridges the middle of the wider box body and provides additional support between its sections.
Firmer Multi-Gang Structure
The center support helps reduce flex across the wider box and creates a firmer structure during switch and socket installation.
35mm Box Depth
The 35mm depth is suitable for common concealed switch and socket installations where a deeper box is not required.
Pre-Punched Knockouts
Knockouts on the selected box panels provide prepared entry points for cables and conduits according to the required wiring layout.
How the Center Support Bar Strengthens the Box
Multi-gang boxes have a wider open span than single-gang boxes. Without support across the middle, the wider structure can be more flexible during transportation, wall fitting and accessory installation.
The fixed center support bar connects the opposing sides of the box at each division. This adds support at the middle of the structure, helps the box maintain its intended shape and provides a steadier base for the installation of switches and sockets.
The support bar is a fixed structural component rather than an adjustable mechanism. Its purpose is to reinforce the box body. If the installation requires adjustable fixing positions, an adjustable-lug model should be selected instead.
Product Specifications
| Item | Available Specification |
|---|---|
| Product Name | 35mm Metal Knockout Box with Center Support Bar |
| Related Product Terms | 35mm Metal Back Box / Metal Knockout Box with Center Connecting Bar |
| Box Depth | 35mm |
| Main Structure | Fixed center support bar |
| Structural Benefit | Firmer support across the wider box body |
| Support Bar Quantity | One or more according to box width and gang layout |
| Box Formats | Two-gang, three-gang and other multi-gang configurations |
| Sheet Thickness | Selected according to the existing model or confirmed specification |
| Knockout Layout | Knockout diameter, quantity and position selected by model or drawing |
| Material and Finish | Metal construction; material grade and surface finish confirmed with the selected model |
| Typical Installation | Concealed or flush-mounted switch and socket installation |
Selecting the Correct Configuration
Please confirm the following information when selecting a 35mm metal knockout box with center support:
- Required gang format and external box dimensions
- Number and position of center support bars
- 35mm depth confirmation
- Required sheet thickness
- Knockout diameter, quantity and cable entry positions
- Switch or socket fixing arrangement
- Required material, surface finish and packaging
Existing Models and Custom Specifications
M&K already offers established 35mm multi-gang metal knockout box configurations with different widths, support-bar arrangements and knockout layouts. We first compare your requirements with these existing models and recommend the closest suitable option.
If an existing model does not match the required gang layout or installation specification, box dimensions, sheet thickness, knockout arrangement, center support structure, finish, branding and packaging can be confirmed against a drawing or sample.
Choose by Structural Requirement
Standard Metal Knockout Box
For regular box configurations that do not require center reinforcement.
Metal Knockout Box with Heavy-Duty Fixing Screw
For requirements focused on a more substantial supplied fixing screw.
46mm Heavy-Gauge Metal Knockout Box with Center Support Bar
For installations that require the same center support together with greater depth and a thicker box body.
Metal Knockout Box with Adjustable Lug
For installations where the fixing position needs adjustment during fitting.
Frequently Asked Questions
What does the center support bar do?
It bridges the middle of the wider box and provides additional structural support, helping create a firmer and more stable multi-gang box body.
Is the center support bar adjustable?
No. It is a fixed structural component designed to reinforce the box. Adjustable positioning is available on a separate adjustable-lug model.
How many center support bars are used?
The quantity depends on the width and gang layout. A two-gang box may use one center support bar, while wider configurations can use additional bars.
What is the difference between this model and the deeper model?
This model uses a 35mm depth and focuses on center reinforcement. The deeper model combines the center support structure with greater internal depth and a thicker box body.
Can the box and support-bar layout be customized?
We first recommend an existing M&K configuration. If it does not meet the required dimensions or gang layout, the box and center support structure can be confirmed from a drawing or sample.
Confirm Your 35mm Box Configuration
Send us the required gang format, box dimensions, sheet thickness, knockout layout and center support arrangement. We will first match your requirements with an established M&K model and confirm any necessary adjustments.
