National Marker N185-199 Spring Door Hinge 3.5 in

Product Description

The NATIONAL MARKER N185-199 is a self-closing spring door hinge designed for hanging doors that must automatically return to a closed position after each use. Built from cold-rolled steel with a 3.5-inch leaf size and a 0.25-inch radius corner profile, this hinge fits standard hinge cutouts without modification. It carries UL approval for fire door applications, making it a code-relevant choice wherever rated door assemblies are required. Closing speed is field-adjustable, allowing installers to tune door swing to suit traffic volume and occupant needs. Sold as a single unit.

This hinge is suited for residential, commercial, and multi-unit apartment installations. Common install locations include basement access doors, interior stairway doors, garage entry doors, and building entrance doors where self-closing function is required by fire code or building management policy. The adjustable spring mechanism makes it practical across a range of door weights and use frequencies. It is cataloged under the V521 series.

Key Features

• UL approved for fire door applications, supporting code-compliant installations
• Adjustable closing speed to accommodate different door weights and traffic levels
• Cold-rolled steel construction for durability in high-cycle door applications
• 0.25-inch radius corner profile fits standard hinge cutouts without additional mortising
• Suitable for residential, commercial, and apartment building use
• Self-closing spring mechanism eliminates the need for a separate door closer on light-duty applications

Compatibility

Designed as an OEM-style replacement or new-installation spring hinge for standard residential and commercial interior doors requiring self-closing function, including UL-listed fire door assemblies.

Installation Notes

Installation is typically performed by a carpenter, general contractor, or facilities maintenance technician. Shut the door and secure the work area before removing any existing hardware. The adjustable spring tension should be set after the hinge is fully mortised and fastened, following the door manufacturer's torque guidance for hinge screws. Fire door installations must conform to the applicable building and fire codes in the jurisdiction, including NFPA 80 requirements for labeled door assemblies.

Technical Specifications

• Leaf Size: 3.5 inches
• Corner Radius: 0.25 inches
• Material: Cold-rolled steel
• Closing Type: Adjustable spring self-closing
• Listing: UL approved for fire doors
• Weight: 0.765 pounds
• Series: V521

Standard Information

• Brand: NATIONAL MARKER
• Manufacturer Part Number: N185-199