National Marker N350868 Spring Door Hinge Satin Nickel

Product Description

The NATIONAL MARKER N350868 is a 4-inch self-closing spring door hinge finished in satin nickel, designed for hanging automatic-closing doors in residential and commercial applications. Manufactured from cold-rolled steel, this hinge features a 1/4-inch corner radius and fits standard hinge cutouts without modification. It carries UL approval for use on fire-rated doors, making it suitable for code-compliant installations where self-closing hardware is required. Closing speed is field-adjustable, giving installers control over latch engagement without replacing the unit. Part of the V521 series, it is sold individually.

This hinge is intended for self-closing door installations in basements, stairways, garages, and entry points across residential, commercial, and apartment building applications. The UL listing for fire doors makes it a practical choice wherever building codes require self-closing hardware on fire-rated door assemblies. The adjustable closing speed allows the installer to match the hinge performance to door weight and traffic conditions on site.

Key Features

• UL approved for fire-rated door assemblies
• Adjustable closing speed for field-tuning latch engagement
• Cold-rolled steel construction with satin nickel finish
• 1/4-inch radius corners fit standard hinge cutouts
• Suitable for residential, commercial, and apartment building use
• Part of the V521 catalog series

Compatibility

Designed as an OEM-style replacement or new-installation hinge for standard door hinge cutouts requiring a 4-inch self-closing spring hinge with a 1/4-inch radius corner profile.

Installation Notes

Installation is typically performed by a finish carpenter, general contractor, or qualified handyman. Power down any connected door hardware or access-control systems before servicing the door frame. Confirm the existing hinge mortise dimensions match the 4-inch leaf size and 1/4-inch radius before installation. Where fire-door compliance is required, verify the installation meets applicable local building codes and manufacturer listing requirements.