National Hardware N104-349 Box Rail Bracket 300 Lb

Product Description

The NATIONAL HARDWARE N104-349 is a galvanized steel single box rail bracket designed to support and mount box rail track systems in sliding door and barn door applications. Rated for 300 pounds of load capacity, this screw-on bracket provides a secure, corrosion-resistant mounting point for box rail hardware. It measures 2 inches in length, 4.5 inches in height, and 2.25 inches in width. The galvanized finish protects against rust and moisture, making it suitable for both interior and light-duty exterior installations. Mounting hardware is included. Installation is straightforward for carpenters, finish contractors, and general tradespeople working with overhead sliding door systems.

This bracket is intended for use with overhead box rail track systems in residential and light commercial sliding door installations. It is specifically compatible with N104-901 or N263-301 box rail. Typical applications include barn doors, bypass closet doors, and utility sliding door setups where a screw-on bracket mount is required. The bracket attaches to a structural header or framing member to carry the rail and door load.

Key Features

• 300 lb load capacity for reliable support of sliding door systems
• Galvanized steel construction resists corrosion and moisture
• Screw-on mount type for straightforward attachment to framing
• Mounting hole diameter of 0.4375 inches for standard fastener compatibility
• Mounting hardware included — no additional fasteners required separately
• Compact profile: 2 inches long, 4.5 inches high, 2.25 inches wide

Compatibility

Designed for use with N104-901 or N263-301 box rail track systems.

Installation Notes

Installation is typically performed by a carpenter or general contractor. Before mounting, confirm that the header or structural member behind the mounting surface is adequate to support the rated 300 lb load. Use appropriately sized fasteners through the 0.4375-inch mounting holes and into solid framing or a structural header. Ensure the rail is level before final fastener tightening to prevent binding of the sliding door.