{"product_id":"national-marker-n184556-square-spring-door-hinge","title":"National Marker N184556 Square Spring Door Hinge","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe NATIONAL MARKER N184556 is a 3.5-inch square spring door hinge finished in satin brass, designed to provide automatic door closing in both residential and commercial applications. Built from cold-rolled steel, this hinge features adjustable closing tension and adjustable closing speed, giving installers direct control over door movement after installation. It fits standard hinge cutouts, eliminating the need for additional mortising or modification. The square corner profile suits standard door and frame preparations. This hinge is listed for fire-rated openings, making it suitable for code-compliant installations where automatic closing hardware is required.\u003c\/p\u003e\u003cp\u003eThis hinge is well suited for a wide range of applications including residential entry doors, commercial office doors, industrial facility doors, and institutional settings such as schools and healthcare facilities. Its fire-rated listing makes it a practical choice wherever building codes mandate self-closing door hardware on rated assemblies. The adjustable tension mechanism allows the closing force to be tuned on-site after installation, which is particularly useful in high-traffic commercial environments where door weight and usage frequency vary.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eAdjustable closing tension for on-site tuning after installation\u003c\/li\u003e\n\u003cli\u003eAdjustable closing speed for controlled door movement\u003c\/li\u003e\n\u003cli\u003eListed for fire-rated door openings\u003c\/li\u003e\n\u003cli\u003eFits standard hinge cutout with square corners — no additional mortising required\u003c\/li\u003e\n\u003cli\u003eCold-rolled steel construction with satin brass finish\u003c\/li\u003e\n\u003cli\u003eSuitable for residential, commercial, industrial, and institutional use\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement or new-installation spring hinge for standard 3.5-inch square-corner hinge preparations on residential and commercial door assemblies.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation is typically performed by a licensed carpenter, door hardware specialist, or general contractor following the door manufacturer's specifications and applicable building codes. Ensure the door and frame are properly aligned before tensioning the spring mechanism, as misalignment can cause premature wear. Adjust closing tension using the appropriate adjustment tool after the door is hung and all fasteners are fully seated. On fire-rated assemblies, verify that all hardware and installation methods comply with the door assembly's fire listing requirements.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize\u003c\/strong\u003e: 3.5 inches square\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCorner Style\u003c\/strong\u003e: Square\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Satin Brass\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Cold-Rolled Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFire Rated\u003c\/strong\u003e: Listed for fire-rated openings\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosing Tension\u003c\/strong\u003e: Adjustable\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClosing Speed\u003c\/strong\u003e: Adjustable\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.785 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: Pack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimum Quantity\u003c\/strong\u003e: 2\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: N184556\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51346344575282,"sku":"N184556","price":54.07,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550227.jpg?v=1782077973","url":"https:\/\/voomisupply.com\/products\/national-marker-n184556-square-spring-door-hinge","provider":"Voomi Supply","version":"1.0","type":"link"}