{"product_id":"national-marker-n350835-spring-door-hinge-3-5-in-satin-nickel","title":"National Marker N350835 Spring Door Hinge 3.5 in Satin Nickel","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe NATIONAL MARKER N350835 is a 3.5-inch self-closing spring door hinge finished in satin nickel. Catalog series V521, it is constructed from cold-rolled steel and features a 1\/4-inch round corner radius. The hinge uses an internal spring mechanism to automatically return a door to the closed position after each use. Closing speed is field-adjustable, allowing installers to tune the return rate to suit door weight and traffic patterns. The N350835 fits standard hinge cutout dimensions, making it a direct drop-in during new installation or replacement work. It is UL approved for use on fire-rated doors, a critical credential for commercial and multi-family residential applications.\u003c\/p\u003e\n\u003cp\u003eThis hinge is designed for hanging self-closing doors in basements, stairways, garages, and entry points. It is suitable for residential, commercial, and apartment building installations. The UL fire-door listing makes it appropriate for installations where code requires a self-closing fire-rated assembly. General contractors, carpenters, and door hardware installers work with this hinge across a wide range of light commercial and residential projects. The adjustable closing speed adds flexibility for high-traffic openings where consistent latching is required.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eUL approved for fire-rated door assemblies\u003c\/li\u003e\n  \u003cli\u003eAdjustable closing speed for tuning to door weight and traffic volume\u003c\/li\u003e\n  \u003cli\u003eCold-rolled steel construction for durability\u003c\/li\u003e\n  \u003cli\u003e1\/4-inch round corner radius fits standard hinge cutouts\u003c\/li\u003e\n  \u003cli\u003eSatin nickel finish suitable for residential and commercial aesthetics\u003c\/li\u003e\n  \u003cli\u003eSold individually (each)\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 3.5-inch hinge cutout door frames in residential, commercial, and apartment building applications where a self-closing or fire-door assembly is required.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is performed by carpenters, door hardware installers, or general contractors. Ensure the door and frame are properly aligned and that the existing or new mortise matches the 3.5-inch leaf size and 1\/4-inch radius corner profile before mounting. On fire-rated assemblies, verify that all hardware used in the assembly carries the appropriate UL listing to maintain the door's fire rating. Adjust the spring tension and closing speed using the manufacturer's adjustment mechanism after the hinge is fully secured.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHinge Size\u003c\/strong\u003e: 3.5 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\u003eCatalog Series\u003c\/strong\u003e: V521\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.78 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: N350835\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51344982278450,"sku":"N350835","price":26.73,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550646.jpg?v=1782047162","url":"https:\/\/voomisupply.com\/products\/national-marker-n350835-spring-door-hinge-3-5-in-satin-nickel","provider":"Voomi Supply","version":"1.0","type":"link"}