Southwire TB-135-UPC 1-gang Steel Masonry Wall Box

Product Description

The SOUTHWIRE TB-135-UPC is a 1-gang steel welded masonry wall box designed for use in concrete block construction. At 2.5 inches deep, it fits standard 4-inch block walls and can serve as a junction box or as a mounting point for a wiring device. The all-steel welded construction provides the structural rigidity required in masonry applications. Electricians working in commercial or industrial masonry block buildings rely on this box for secure device mounting. It carries UL listing and is RoHS compliant, meeting common project and specification requirements.

This box is suited for new construction and retrofit work in masonry block walls where a 4-inch block is used. It functions as a single-gang wiring device enclosure or junction box. The gangable design allows multiple units to be joined side by side, giving installers the flexibility to build up multi-gang configurations on the job without stocking a separate multi-gang box. Typical installations include commercial buildings, schools, warehouses, and other structures where masonry block is the primary wall system.

Key Features

• 2.5-inch depth fits standard 4-inch masonry block walls
• Gangable design allows side-by-side joining for multi-device configurations
• Steel welded construction for durability in masonry environments
• Functions as a junction box or wiring device mounting box
• UL listed and RoHS compliant

Compatibility

Designed as an OEM-style replacement or new-installation masonry box for 1-gang wiring device applications in 4-inch concrete block wall construction.

Installation Notes

Installation is typically performed by a licensed electrician in accordance with NFPA 70 (NEC) requirements for box fill and device mounting. Power down the circuit at the breaker before any wiring connections are made. Secure the box in the masonry opening using appropriate mortar or anchoring method before pulling conductors. When ganging multiple boxes, ensure all knockout knockouts and gang attachments are properly aligned before setting in the wall.

Technical Specifications

• Gang Configuration: 1-Gang
• Box Depth: 2.5 inches
• Wall Application: 4-inch masonry block
• Material: Steel, welded
• Weight: 0.89 pounds
• Certifications: UL Listed, RoHS Compliant

Standard Information

• Brand: SOUTHWIRE
• Manufacturer Part Number: TB-135-UPC