{"product_id":"national-marker-n351023-spring-door-hinge-4-in-satin-nickel","title":"National Marker N351023 Spring Door Hinge 4 in Satin Nickel","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe 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.\u003c\/p\u003e\n\u003cp\u003eThis 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.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e4-inch leaf size with 5\/8-inch radius corners fits standard hinge mortises\u003c\/li\u003e\n  \u003cli\u003eCold-rolled steel construction for strength and durability\u003c\/li\u003e\n  \u003cli\u003eAdjustable closing speed lets the installer set door swing resistance on site\u003c\/li\u003e\n  \u003cli\u003eAdjustable tension accommodates varying door weights and usage conditions\u003c\/li\u003e\n  \u003cli\u003eUL listed for fire-rated door assemblies, supporting code-compliant installations\u003c\/li\u003e\n  \u003cli\u003eSatin nickel finish for corrosion resistance and finish compatibility\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned 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.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation 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.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\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: 5\/8 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Satin Nickel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Cold-Rolled Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eClosing Speed\u003c\/strong\u003e: Adjustable\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTension\u003c\/strong\u003e: Adjustable\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUL Listed\u003c\/strong\u003e: Yes, for fire-rated doors\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.869 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCatalog Model\u003c\/strong\u003e: V522\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: N351023\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51342877425970,"sku":"N351023","price":30.31,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550656.jpg?v=1782009328","url":"https:\/\/voomisupply.com\/products\/national-marker-n351023-spring-door-hinge-4-in-satin-nickel","provider":"Voomi Supply","version":"1.0","type":"link"}