National Marker N350884 Spring Door Hinge 3.5 in Oil Rubbed Bronze

Product Description

The NATIONAL MARKER N350884 is a 3.5-inch oil rubbed bronze spring door hinge with a 5/8-inch corner radius, designed for self-closing door applications in residential and light commercial construction. Built from cold-rolled steel, this hinge features independently adjustable closing speed and tension, allowing installers to dial in performance without replacing hardware. It carries UL approval for use on fire-rated doors, making it suitable where code-compliant self-closing assemblies are required. The hinge fits standard door hinge cutouts, simplifying retrofits and new installations alike.

This hinge is used in applications where doors must self-close automatically, including fire-rated corridor doors, stairwell entries, and unit separation doors in multi-family or commercial buildings. It is equally suited for residential interior doors where a controlled close is preferred. Because it fits a standard hinge cutout, it can replace conventional butt hinges in most door preparations without modification. Licensed carpenters, door hardware specialists, and general contractors typically install this type of hardware during rough or finish carpentry phases.

Key Features

• Adjustable closing speed lets installers set the rate of door travel after release
• Adjustable tension controls the force required to open the door against the spring
• UL approved for fire-rated door assemblies where self-closing hardware is required by code
• Fits standard hinge cutout for direct replacement of conventional butt hinges
• Cold-rolled steel construction for consistent spring performance and durability
• Oil rubbed bronze finish for compatibility with period and transitional door hardware sets

Compatibility

Designed as an OEM-style replacement spring hinge for standard residential and light commercial door preparations requiring a 3.5-inch hinge with a 5/8-inch radius corner. Also cataloged as National model V522.

Installation Notes

Installation is typically performed by a carpenter or door hardware installer using standard hand tools. Remove existing door hardware and ensure the hinge mortise matches the 3.5-inch leaf size before installation. On fire-rated door assemblies, verify that the complete door, frame, and hardware system maintains its listed rating per applicable building and fire codes. Adjust closing speed and tension only after the hinge is fully fastened and the door is hung and aligned.

Technical Specifications

• Hinge Size: 3.5 inches
• Corner Radius: 5/8 inch
• Finish: Oil Rubbed Bronze
• Material: Cold-Rolled Steel
• Closing Speed: Adjustable
• Tension: Adjustable
• Fire Door Rating: UL Approved
• Weight: 0.78 pounds
• UPC: 00038613350885

Standard Information

• Brand: NATIONAL MARKER
• Manufacturer Part Number: N350884