{"product_id":"national-marker-n185207-spring-door-hinge-brass","title":"National Marker N185207 Spring Door Hinge Brass","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe 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.\u003c\/p\u003e\n\u003cp\u003eThis 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.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eAutomatic self-closing spring mechanism with adjustable closing speed\u003c\/li\u003e\n  \u003cli\u003eUL approved for fire door installations\u003c\/li\u003e\n  \u003cli\u003e4 inch hinge leaf size with 1\/4 inch corner radius for standard cutout compatibility\u003c\/li\u003e\n  \u003cli\u003eCold-rolled steel construction with brass finish\u003c\/li\u003e\n  \u003cli\u003eFits standard hinge cutouts — no mortise modification required\u003c\/li\u003e\n  \u003cli\u003eSuitable for residential, commercial, and apartment building applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned 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.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation 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.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: V521\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHinge Size\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCorner Radius\u003c\/strong\u003e: 1\/4 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Cold-rolled steel with brass finish\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClosing Speed\u003c\/strong\u003e: Adjustable\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUL Listed\u003c\/strong\u003e: Yes, fire door rated\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.897 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSold As\u003c\/strong\u003e: Each\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: NATIONAL MARKER\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: N185207\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51345784373554,"sku":"N185207","price":40.02,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550225.jpg?v=1782062862","url":"https:\/\/voomisupply.com\/products\/national-marker-n185207-spring-door-hinge-brass","provider":"Voomi Supply","version":"1.0","type":"link"}