National Mfg N350-835 3.5in Spring Adjustable Door Hinge

Product Description

The NATIONAL MFG/SPECTRUM BRANDS HHI N350-835 is a 3.5-inch satin nickel spring adjustable door hinge designed for standard residential and light commercial door installations. Manufactured from cold rolled steel, this hinge features adjustable closing speed and adjustable spring tension, allowing the installer to dial in the right resistance and return rate for the door weight and traffic conditions. The hinge is UL approved for use on fire-rated doors, making it suitable for code-required applications. Package includes two hinges.

This hinge fits standard hinge cutouts, simplifying installation on new construction and replacement projects alike. The 1/4-inch radius round corners match the most common door and frame mortise profile found in residential and light commercial construction. The satin nickel finish suits interior door applications where a brushed metal appearance is specified. Licensed contractors, carpenters, and door hardware installers working on fire-rated corridor doors, stairwell doors, or standard passage doors will find this a direct drop-in replacement in most existing cutouts.

Key Features

• Adjustable closing speed lets the installer control how quickly the door returns to closed position
• Adjustable spring tension accommodates varying door weights and usage frequencies
• UL approved for fire-rated door applications, supporting code-compliant installations
• Fits standard hinge cutout — no mortise modification required in most cases
• 1/4-inch radius round corners match the most common door and frame profile
• Cold rolled steel construction for durability in high-cycle door applications
• Satin nickel finish provides a clean, brushed appearance for interior use

Compatibility

Designed as an OEM-style replacement or new-installation spring hinge for standard residential and light commercial doors with a 3.5-inch hinge mortise cutout and 1/4-inch radius corners.

Installation Notes

Installation is typically performed by a licensed carpenter, door hardware installer, or general contractor. Remove the door from the frame before replacing hinges and ensure power tools are not required near electrical panels or live circuits. For fire-rated door assemblies, verify that all hardware, including the hinge, meets the requirements of the applicable fire door listing and local building code before installation. Confirm the spring tension adjustment is set and tested before returning the door to service.