{"product_id":"national-marker-n350884-spring-door-hinge-3-5-in-oil-rubbed-bronze","title":"National Marker N350884 Spring Door Hinge 3.5 in Oil Rubbed Bronze","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe NATIONAL MARKER N350884 is a 3.5-inch oil rubbed bronze spring door hinge with a 5\/8-inch corner radius, designed for self-closing door applications in residential and light commercial construction. Built from cold-rolled steel, this hinge features independently adjustable closing speed and tension, allowing installers to dial in performance without replacing hardware. It carries UL approval for use on fire-rated doors, making it suitable where code-compliant self-closing assemblies are required. The hinge fits standard door hinge cutouts, simplifying retrofits and new installations alike.\u003c\/p\u003e\n\u003cp\u003eThis hinge is used in applications where doors must self-close automatically, including fire-rated corridor doors, stairwell entries, and unit separation doors in multi-family or commercial buildings. It is equally suited for residential interior doors where a controlled close is preferred. Because it fits a standard hinge cutout, it can replace conventional butt hinges in most door preparations without modification. Licensed carpenters, door hardware specialists, and general contractors typically install this type of hardware during rough or finish carpentry phases.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eAdjustable closing speed lets installers set the rate of door travel after release\u003c\/li\u003e\n  \u003cli\u003eAdjustable tension controls the force required to open the door against the spring\u003c\/li\u003e\n  \u003cli\u003eUL approved for fire-rated door assemblies where self-closing hardware is required by code\u003c\/li\u003e\n  \u003cli\u003eFits standard hinge cutout for direct replacement of conventional butt hinges\u003c\/li\u003e\n  \u003cli\u003eCold-rolled steel construction for consistent spring performance and durability\u003c\/li\u003e\n  \u003cli\u003eOil rubbed bronze finish for compatibility with period and transitional door hardware sets\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style replacement spring hinge for standard residential and light commercial door preparations requiring a 3.5-inch hinge with a 5\/8-inch radius corner. Also cataloged as National model V522.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is typically performed by a carpenter or door hardware installer using standard hand tools. Remove existing door hardware and ensure the hinge mortise matches the 3.5-inch leaf size before installation. On fire-rated door assemblies, verify that the complete door, frame, and hardware system maintains its listed rating per applicable building and fire codes. Adjust closing speed and tension only after the hinge is fully fastened and the door is hung and aligned.\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: 5\/8 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Oil Rubbed Bronze\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\u003eFire Door Rating\u003c\/strong\u003e: UL Approved\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.78 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUPC\u003c\/strong\u003e: 00038613350885\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: N350884\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51343981642034,"sku":"N350884","price":27.26,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550645.jpg?v=1782026229","url":"https:\/\/voomisupply.com\/products\/national-marker-n350884-spring-door-hinge-3-5-in-oil-rubbed-bronze","provider":"Voomi Supply","version":"1.0","type":"link"}