{"product_id":"national-mfg-n350-827-3-5in-spring-door-hinge-oil-rubbed-bronze","title":"National Mfg N350-827 3.5in Spring Door Hinge Oil Rubbed Bronze","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe NATIONAL MFG\/SPECTRUM BRANDS HHI N350-827 is a 3.5-inch spring-loaded, self-closing door hinge finished in oil rubbed bronze. Constructed from cold rolled steel, this hinge features independently adjustable closing speed and tension, giving installers precise control over door swing and return force. It is UL approved for use on fire-rated doors, making it suitable for applications where code compliance is required. The 1\/4-inch radius round corners allow it to drop into standard hinge cutouts without additional mortising. This hinge is sold in a package of two units.\u003c\/p\u003e\n\u003cp\u003eThis hinge is appropriate for residential and light commercial door installations where a self-closing function is required. Common applications include fire-rated corridor doors, utility room doors, and any passage door where building code or facility policy mandates automatic closure. The oil rubbed bronze finish suits interior doors in settings where a darker, traditional hardware aesthetic is specified. Installation is handled by general contractors, carpenters, or door hardware specialists.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eAdjustable closing speed for controlled, consistent door return\u003c\/li\u003e\n  \u003cli\u003eAdjustable spring tension to match door weight and swing resistance\u003c\/li\u003e\n  \u003cli\u003eUL approved for fire-rated door applications\u003c\/li\u003e\n  \u003cli\u003eFits standard hinge cutouts with 1\/4-inch radius round corners\u003c\/li\u003e\n  \u003cli\u003eCold rolled steel construction for durability\u003c\/li\u003e\n  \u003cli\u003eOil rubbed bronze finish for a traditional hardware appearance\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 residential and light commercial door frames using a 3.5-inch hinge cutout.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is typically performed by a carpenter or door hardware technician using a screwdriver and, where needed, a chisel for mortise preparation. Confirm the door frame hinge cutout dimensions match 3.5 inches before installation. On fire-rated assemblies, verify that the full door and frame assembly maintains its UL listing after hardware substitution, as required by the applicable fire code. Adjust closing speed and tension only with the door in place and all fasteners fully seated.\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: 0.25 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Cold Rolled Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Oil Rubbed Bronze\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpring Type\u003c\/strong\u003e: Adjustable closing speed and tension\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFire Door Rating\u003c\/strong\u003e: UL Approved\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Quantity\u003c\/strong\u003e: 2 units\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 1.5 pounds\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 MFG\/SPECTRUM BRANDS HHI\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: N350-827\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL HARDWARE","offers":[{"title":"Default Title","offer_id":51562309189938,"sku":"N350-827","price":39.07,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/b22ce8163b3cbfcd5671ba30345b2a47.jpg?v=1786475085","url":"https:\/\/voomisupply.com\/products\/national-mfg-n350-827-3-5in-spring-door-hinge-oil-rubbed-bronze","provider":"Voomi Supply","version":"1.0","type":"link"}