{"product_id":"national-marker-n350801-square-spring-door-hinge-4-in-satin-nickel","title":"National Marker N350801 Square Spring Door Hinge 4 in Satin Nickel","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe NATIONAL MARKER N350801 is a 4-inch square spring door hinge finished in satin nickel, designed to provide controlled self-closing action on standard door installations. Part of the V520 series, this hinge features adjustable tension and adjustable closing speed, giving installers precise control over door movement after installation. Constructed from cold-rolled steel, it fits standard hinge cutouts with square corners and is listed for fire-rated openings. It is appropriate for residential, commercial, industrial, and institutional applications where a reliable, code-compliant self-closing hinge is required.\u003c\/p\u003e\n\u003cp\u003eThis hinge is suited for a wide range of door installations where self-closing function is needed, including fire-rated door assemblies. Its adjustable tension mechanism makes it adaptable to doors of varying weights and swing characteristics. The satin nickel finish provides a clean, neutral appearance compatible with standard door hardware. Installers will find it compatible with existing standard hinge cutout routing on both new construction and retrofit projects across residential and light commercial settings.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eListed for fire-rated door openings, meeting code requirements for self-closing assemblies\u003c\/li\u003e\n  \u003cli\u003eAdjustable tension allows field calibration to door weight and desired resistance\u003c\/li\u003e\n  \u003cli\u003eAdjustable closing speed for controlled, consistent door closure\u003c\/li\u003e\n  \u003cli\u003eFits standard hinge cutout — no additional mortising required on properly prepped doors\u003c\/li\u003e\n  \u003cli\u003eCold-rolled steel construction with satin nickel finish\u003c\/li\u003e\n  \u003cli\u003eSquare corners for compatibility with standard door and frame prep\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 4-inch hinge cutout doors in residential, commercial, industrial, and institutional applications where fire-rated self-closing hardware is specified.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation should be performed by a qualified carpenter, door hardware installer, or general contractor familiar with fire-rated opening requirements. Before replacing an existing hinge, ensure the door is properly supported to prevent movement during hardware swap. When installing on fire-rated assemblies, verify that the complete door and frame assembly maintains its fire-rating listing after hardware installation, in accordance with applicable building and fire codes. Tension and closing speed adjustments should be made after the hinge is fully fastened and the door is hung.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSize\u003c\/strong\u003e: 4 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Satin Nickel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCorner Style\u003c\/strong\u003e: Square\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Cold-Rolled Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFire Rating\u003c\/strong\u003e: Listed for fire-rated openings\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\u003eWeight\u003c\/strong\u003e: 0.881 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: V520\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUOM\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: N350801\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51343415279922,"sku":"N350801","price":30.33,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550648.jpg?v=1782021310","url":"https:\/\/voomisupply.com\/products\/national-marker-n350801-square-spring-door-hinge-4-in-satin-nickel","provider":"Voomi Supply","version":"1.0","type":"link"}