Description

The NATIONAL MFG/SPECTRUM BRANDS HHI N350-827 is a 3.5-inch spring-loaded, self-closing door hinge finished in oil rubbed bronze. Constructed from cold rolled steel, this hinge features independently adjustable closing speed and tension, giving installers precise control over door swing and return force. It is UL approved for use on fire-rated doors, making it suitable for applications where code compliance is required. The 1/4-inch radius round corners allow it to drop into standard hinge cutouts without additional mortising. This hinge is sold in a package of two units.

This hinge is appropriate for residential and light commercial door installations where a self-closing function is required. Common applications include fire-rated corridor doors, utility room doors, and any passage door where building code or facility policy mandates automatic closure. The oil rubbed bronze finish suits interior doors in settings where a darker, traditional hardware aesthetic is specified. Installation is handled by general contractors, carpenters, or door hardware specialists.

Key Features

Adjustable closing speed for controlled, consistent door return
Adjustable spring tension to match door weight and swing resistance
UL approved for fire-rated door applications
Fits standard hinge cutouts with 1/4-inch radius round corners
Cold rolled steel construction for durability
Oil rubbed bronze finish for a traditional hardware appearance

Compatibility

Designed as an OEM-style replacement or new-installation spring hinge for standard residential and light commercial door frames using a 3.5-inch hinge cutout.

Installation Notes

Installation is typically performed by a carpenter or door hardware technician using a screwdriver and, where needed, a chisel for mortise preparation. Confirm the door frame hinge cutout dimensions match 3.5 inches before installation. On fire-rated assemblies, verify that the full door and frame assembly maintains its UL listing after hardware substitution, as required by the applicable fire code. Adjust closing speed and tension only with the door in place and all fasteners fully seated.