{"product_id":"national-marker-n350868-spring-door-hinge-satin-nickel","title":"National Marker N350868 Spring Door Hinge Satin Nickel","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe 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.\u003c\/p\u003e\u003cp\u003eThis 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.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eUL approved for fire-rated door assemblies\u003c\/li\u003e\n\u003cli\u003eAdjustable closing speed for field-tuning latch engagement\u003c\/li\u003e\n\u003cli\u003eCold-rolled steel construction with satin nickel finish\u003c\/li\u003e\n\u003cli\u003e1\/4-inch radius corners fit standard hinge cutouts\u003c\/li\u003e\n\u003cli\u003eSuitable for residential, commercial, and apartment building use\u003c\/li\u003e\n\u003cli\u003ePart of the V521 catalog series\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned 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.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation 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.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\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: 1\/4 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 Type\u003c\/strong\u003e: Spring Self-Closing, Adjustable Speed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFire Door Rating\u003c\/strong\u003e: UL Approved\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.878 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: V521\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSold As\u003c\/strong\u003e: Each\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\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: N350868\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51343437037874,"sku":"N350868","price":30.06,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550644.jpg?v=1782021449","url":"https:\/\/voomisupply.com\/products\/national-marker-n350868-spring-door-hinge-satin-nickel","provider":"Voomi Supply","version":"1.0","type":"link"}