{"product_id":"national-marker-n184572-square-spring-door-hinge","title":"National Marker N184572 Square Spring Door Hinge","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe NATIONAL MARKER N184572 is a 4-inch square spring door hinge finished in satin brass, designed to provide controlled, self-closing action on standard door installations. Part of the V520 series, it features adjustable tension and adjustable closing speed, giving installers precise control over door return force and swing rate. The hinge is manufactured from cold-rolled steel and is listed for fire-rated openings, making it suitable for applications where code-compliant self-closing hardware is required. It fits standard hinge cutouts with square corners, simplifying direct replacement and new installation alike.\u003c\/p\u003e\n\u003cp\u003eThis hinge is suited for a wide range of door applications including residential, commercial, industrial, and institutional settings. Its fire-rated listing makes it a common choice for stairwell doors, corridor doors, and other openings required by code to be self-closing. The adjustable tension allows the installer to dial in the appropriate closing force for the door weight and application, reducing the need for field callbacks or hardware swaps.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eListed for fire-rated door openings, meeting self-closing hardware requirements\u003c\/li\u003e\n  \u003cli\u003eAdjustable tension and closing speed for field-tuned door control\u003c\/li\u003e\n  \u003cli\u003eCold-rolled steel construction for durability in high-cycle applications\u003c\/li\u003e\n  \u003cli\u003eFits standard hinge cutout with square corners for straightforward installation\u003c\/li\u003e\n  \u003cli\u003eSatin brass finish suitable for residential and commercial aesthetic requirements\u003c\/li\u003e\n  \u003cli\u003eRated for residential, commercial, industrial, and institutional use\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 door preparations requiring a 4-inch square corner hinge cutout across residential, commercial, industrial, and institutional door applications.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is typically performed by a licensed carpenter, general contractor, or door hardware professional. Verify that the door and frame are properly prepared to accept a 4-inch square corner hinge before installation. For fire-rated openings, confirm the hinge listing is appropriate for the door and frame assembly per applicable building and fire codes. Adjust tension and closing speed per the manufacturer instructions after the hinge is fully mounted and the door is hung.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: V520\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSize\u003c\/strong\u003e: 4 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: Yes, 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: 0.885 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUnit of Measure\u003c\/strong\u003e: Pack\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMinimum Order Quantity\u003c\/strong\u003e: 2\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: N184572\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"NATIONAL MARKER","offers":[{"title":"Default Title","offer_id":51346624184626,"sku":"N184572","price":61.6,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/310550228.jpg?v=1782085780","url":"https:\/\/voomisupply.com\/products\/national-marker-n184572-square-spring-door-hinge","provider":"Voomi Supply","version":"1.0","type":"link"}