4" x 1-1/2" Utility Box, 17 Knockouts, Steel, Square

Bramec 13431 – 4" Square Steel Utility Box, 1-1/2" Deep, 17 Knockouts

The Bramec 13431 is a 4-inch square, 1-1/2 inch deep steel utility box designed for use in surface or concealed wall applications. Constructed from galvanized steel, this box supports branch circuit wiring and device mounting in commercial and residential environments. Its design includes 17 total knockouts to accommodate various conduit entry configurations and is commonly used for switch, receptacle, and splicing applications where a shallow wall cavity is present.

Compliant with NEC fill volume requirements, this box is compatible with standard mud rings, raised covers, and device brackets used in 4" square enclosure systems. Its compact profile is ideal for thru-the-wall assemblies and shallow-depth framing spaces.

Core Product Features

• ✅ Box Size: 4" square with 1-1/2" depth – suited for installations with space constraints.
• ✅ Knockouts: 17 total – mix of 1/2" and TKO (combination 1/2" and 3/4") knockouts for side and bottom conduit entries.
• ✅ Material: Pre-galvanized steel – provides corrosion resistance in standard dry indoor environments.
• ✅ Application: Use with EMT, MC, or flex conduit systems in junction or device box installations.

Technical Specifications

• Manufacturer: Bramec
• Part Number: 13431
• Box Dimensions: 4" x 4" x 1-1/2"
• Volume: 21.0 cu. in.
• Knockouts: 17 (side and bottom)
• Material: Steel, galvanized finish
• Mounting: Welded back for surface or stud mounting; compatible with standard box supports

Installation Notes

The Bramec 13431 is intended for use in accessible areas with shallow framing or where multiple device installations are aligned vertically or horizontally. It accepts standard device rings and cover plates and can be mounted using typical stud brackets or bar hangers. Installation must comply with NEC Article 314 and local electrical codes, especially regarding conductor fill, bonding, and box support.

Field Use and Compatibility

Commonly used in light commercial buildings, tenant improvements, utility spaces, and retrofits, this box accommodates switches, duplex outlets, or low-voltage terminations. It is compatible with most 4-inch square plaster rings, fan control devices, and wall switch assemblies in single- or multi-device configurations.

Professional Considerations

• ✅ Supports Horizontal and Vertical Conduit Runs – Multiple knockouts allow flexibility in pipe layout without field modification.
• ✅ UL Listed – Suitable for use in code-compliant electrical systems requiring metallic enclosures.
• ✅ Device Compatibility – Matches standard 4" square covers and extension rings used in switch or receptacle installations.
• ✅ Field Ready – Galvanized finish and formed box edges simplify conduit termination and box grounding.