National Mfg N273-938 4.5 Inch Steel Door Hinge 5-pack

Product Description

The NATIONAL MFG/SPECTRUM BRANDS HHI N273-938 is a plain steel door hinge built for surface application by welding. Manufactured from cold rolled steel, this non-swaged hinge measures 4.5 inches and features a five-knuckle, full mortise design with a tight pin for added security. The weldable construction makes it well suited for industrial, commercial, and heavy-duty door installations where a bolted or screwed hinge is not practical. Each pack contains five hinges, sold boxed loose. Installation is handled by ironworkers, millwrights, or experienced carpenters working on steel door frames.

This hinge is designed for surface-mount welding applications on steel doors and frames. The full mortise design allows the hinge leaf to sit flush within a routed pocket, keeping the door face clean and reducing stress concentration at the hinge point. The tight pin configuration resists loosening over time, making it appropriate for high-cycle or high-traffic door applications in commercial and industrial settings. The cold rolled steel construction provides consistent dimensional tolerance and weldability across the hinge body.

Key Features

• Weldable, non-swaged design for surface application by welding
• Cold rolled steel construction for consistent weldability and strength
• Five-knuckle, full mortise design for flush installation
• Tight pin for increased security and reduced play
• 4.5-inch hinge size suitable for heavy-duty door applications
• Sold in a pack of 5, boxed loose

Compatibility

Designed as an OEM-style replacement or new-installation hinge for steel doors and frames requiring a weldable, full mortise hinge in a 4.5-inch form factor.

Installation Notes

Installation requires welding equipment and should be performed by a qualified tradesperson familiar with steel door frame fabrication. Power down or de-energize any associated door hardware systems before beginning work. Ensure the mortise pocket is cut to proper depth before welding to maintain flush leaf alignment. Follow applicable local building codes for door hinge placement and spacing requirements.