National Marker N351023 Spring Door Hinge 4 in Satin Nickel

Product Description

The NATIONAL MARKER N351023 is a 4-inch satin nickel spring door hinge with a 5/8-inch corner radius, cataloged under National model V522. Constructed from cold-rolled steel, this hinge is built for durability in both residential and light commercial door applications. Closing speed and tension are both field-adjustable, allowing the installer to dial in the correct resistance for the door weight and swing. The hinge carries UL approval for use on fire-rated doors, making it suitable for code-required installations where listed hardware is mandatory.

This spring hinge is designed for standard hinge cutout sizes, allowing it to drop into existing mortises without modification in most cases. It is appropriate for interior fire-rated door assemblies in commercial buildings, multifamily residential construction, and institutional settings. Installers working on fire door compliance projects will find the UL listing directly relevant to AHJ requirements. The satin nickel finish suits common hardware finish schedules in both new construction and renovation work.

Key Features

• 4-inch leaf size with 5/8-inch radius corners fits standard hinge mortises
• Cold-rolled steel construction for strength and durability
• Adjustable closing speed lets the installer set door swing resistance on site
• Adjustable tension accommodates varying door weights and usage conditions
• UL listed for fire-rated door assemblies, supporting code-compliant installations
• Satin nickel finish for corrosion resistance and finish compatibility

Compatibility

Designed as an OEM-style replacement or new-installation spring hinge for standard hinge cutout door frames in residential and commercial applications where a 4-inch UL-listed spring hinge is specified.

Installation Notes

Installation is typically performed by a finish carpenter, general contractor, or door hardware specialist. Adjust closing speed and tension using the adjustment features on the hinge barrel before final door operation is tested. Fire door hardware must be installed in accordance with the door and frame manufacturer specifications and applicable fire codes to maintain the door assembly listing. Verify that all hardware on a fire-rated assembly is listed and compatible before completing the installation.

Technical Specifications

• Hinge Size: 4 inches
• Corner Radius: 5/8 inch
• Finish: Satin Nickel
• Material: Cold-Rolled Steel
• Closing Speed: Adjustable
• Tension: Adjustable
• UL Listed: Yes, for fire-rated doors
• Weight: 0.869 pounds
• Catalog Model: V522

Standard Information

• Brand: NATIONAL MARKER
• Manufacturer Part Number: N351023