National Marker N185207 Spring Door Hinge Brass

Product Description

The NATIONAL MARKER N185207 is a 4-inch brass spring door hinge engineered for self-closing door applications in residential, commercial, and multi-unit building installations. Part of the V521 series, this hinge features a 1/4 inch corner radius and is constructed from cold-rolled steel with a brass finish. The spring mechanism provides automatic door closure with an adjustable closing speed, making it a practical choice for fire-rated door assemblies and high-traffic entryways. Installation professionals will appreciate that it fits standard hinge cutouts without modification, keeping retrofit work straightforward.

This hinge is suited for hanging self-closing doors in basements, stairways, garages, and building entrances. It carries UL approval for fire door applications, making it a code-compliant option for projects that require listed hardware. The adjustable closing speed accommodates different door weights and swing requirements across a range of interior and exterior applications in both residential and commercial settings.

Key Features

• Automatic self-closing spring mechanism with adjustable closing speed
• UL approved for fire door installations
• 4 inch hinge leaf size with 1/4 inch corner radius for standard cutout compatibility
• Cold-rolled steel construction with brass finish
• Fits standard hinge cutouts — no mortise modification required
• Suitable for residential, commercial, and apartment building applications

Compatibility

Designed as an OEM-style replacement and new-installation spring hinge for standard-mortise door frames requiring self-closing hardware, including fire-rated door assemblies in residential and commercial construction.

Installation Notes

Installation is typically performed by a licensed carpenter, door hardware technician, or general contractor. Power down any electric door hardware and confirm the door is properly secured before removing existing hinges. Consult local building codes and the applicable fire door listing requirements when installing on fire-rated assemblies. Closing speed adjustment should be made with the door fully hung and latched to ensure correct tension calibration.

Technical Specifications

• Series: V521
• Hinge Size: 4 inches
• Corner Radius: 1/4 inch
• Material: Cold-rolled steel with brass finish
• Closing Speed: Adjustable
• UL Listed: Yes, fire door rated
• Weight: 0.897 pounds
• Sold As: Each

Standard Information

• Brand: NATIONAL MARKER
• Manufacturer Part Number: N185207