{"product_id":"heli-coil-a3591-5cn469-5-16-24-unf-locking-insert-304-ss","title":"Heli-coil A3591-5CN469 5\/16-24 Unf Locking Insert 304 Ss","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe HELI-COIL A3591-5CN469 is a tangless, screw-locking helical coil insert designed to provide a durable, vibration-resistant threaded hole in parent materials that may be softer or prone to thread wear. Manufactured from Grade 304 stainless steel with a bright finish, this insert accepts a 5\/16-24 UNF fastener and delivers a length-to-diameter ratio of 1-1\/2D with an overall length of 0.469 inches. The locking design holds a maximum locking torque of 60 inch-pounds, preventing fastener back-out under dynamic loads. Licensed machinists, maintenance technicians, and MRO professionals install these inserts to restore or reinforce tapped holes in metal assemblies across industrial, aerospace, and marine applications.\u003c\/p\u003e\n\u003cp\u003eThis insert is suited for use in precision assemblies where corrosion resistance and thread integrity are both critical. The tangless design eliminates the need for a tang removal step after installation, reducing assembly time and removing the risk of a loose tang fragment inside a closed assembly. Typical applications include repair of stripped threads in aluminum housings, stainless or steel weldments, and high-cycle fastener locations in equipment subject to vibration or repeated disassembly. The 5\/16-24 UNF thread form is common in precision mechanical and hydraulic component assemblies.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eTangless coil design eliminates post-installation tang removal and prevents debris in closed assemblies\u003c\/li\u003e\n  \u003cli\u003eGrade 304 stainless steel construction for corrosion resistance in wet, marine, or chemical environments\u003c\/li\u003e\n  \u003cli\u003eMaximum locking torque of 60 inch-pounds for reliable vibration-resistant fastener retention\u003c\/li\u003e\n  \u003cli\u003eMinimum break-away torque of 6.50 ounce-inches maintains prevailing torque through repeated use\u003c\/li\u003e\n  \u003cli\u003e1-1\/2D length-to-diameter ratio at 0.469 inches overall length suits standard thread engagement requirements\u003c\/li\u003e\n  \u003cli\u003eOutside diameter range of 0.380 to 0.400 inches with 8-7\/8 free coils for consistent installation fit\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style threaded insert for parent holes tapped to accept 5\/16-24 UNF helical coil inserts per applicable HELI-COIL installation standards.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation requires a properly sized HELI-COIL tap and the appropriate tangless installation tool for the 5\/16-24 UNF insert series. Ensure the parent hole is drilled and tapped to the correct HELI-COIL oversize specification before driving the insert. Power down and de-energize any equipment before performing thread repair on in-service assemblies. Do not attempt installation without the correct installation mandrel, as improvised tools can distort the coil and compromise locking performance.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 5\/16-24\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Standard\u003c\/strong\u003e: UNF\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Insert Length\u003c\/strong\u003e: 0.469 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eLength to Diameter Ratio\u003c\/strong\u003e: 1-1\/2D\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMinimum Outside Diameter\u003c\/strong\u003e: 0.380 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaximum Outside Diameter\u003c\/strong\u003e: 0.400 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Free Coils\u003c\/strong\u003e: 8-7\/8\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaximum Locking Torque\u003c\/strong\u003e: 60 inch-pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMinimum Break-Away Torque\u003c\/strong\u003e: 6.50 ounce-inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Stainless Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial Grade\u003c\/strong\u003e: 304\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoating\/Finish\u003c\/strong\u003e: Bright\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTang\u003c\/strong\u003e: Tangless\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Inserts\u003c\/strong\u003e: 1\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: HELI-COIL\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: A3591-5CN469\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HELI-COIL","offers":[{"title":"Default Title","offer_id":51988371341618,"sku":"A3591-5CN469","price":26.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/32f655f4b5aa6974cf10f814892e22ea.jpg?v=1789987516","url":"https:\/\/voomisupply.com\/products\/heli-coil-a3591-5cn469-5-16-24-unf-locking-insert-304-ss","provider":"Voomi Supply","version":"1.0","type":"link"}