{"product_id":"heli-coil-a3585-5cn781-screw-locking-insert-5-16-18-unc","title":"Heli-coil A3585-5CN781 Screw-locking Insert 5\/16-18 Unc","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe HELI-COIL A3585-5CN781 is a tangless screw-locking helical coil insert designed to provide vibration-resistant thread reinforcement in threaded assemblies. Manufactured from Grade 304 stainless steel with a bright finish, this insert accepts a 5\/16-18 UNC thread and measures 0.781 inches overall length, corresponding to a 2-1\/2D length-to-diameter ratio. It delivers a maximum locking torque of 60 in\/lb and a minimum breakaway torque of 7.50 in\/lb. The tangless design eliminates the need for tang removal after installation, reducing assembly time and the risk of loose fragments in the assembly. It is installed by licensed machine technicians, maintenance professionals, and precision assembly workers.\u003c\/p\u003e\u003cp\u003eThis insert is suited for applications requiring durable thread repair or thread reinforcement in stainless-compatible parent materials. The 5\/16-18 UNC thread form fits standard unified coarse-thread fastener systems common in industrial, aerospace-adjacent, and general mechanical assemblies. The 11-7\/8 free coils and the locking feature make it appropriate for joints subject to vibration or repeated fastener removal. Sold individually with a minimum order quantity of 5 units.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eTangless design eliminates post-installation tang removal step\u003c\/li\u003e\n\u003cli\u003eGrade 304 stainless steel construction resists corrosion in wet or chemically active environments\u003c\/li\u003e\n\u003cli\u003eMaximum locking torque of 60 in\/lb provides secure vibration-resistant thread engagement\u003c\/li\u003e\n\u003cli\u003eMinimum breakaway torque of 7.50 in\/lb ensures positive locking action is maintained\u003c\/li\u003e\n\u003cli\u003e0.781 inches overall length at 2-1\/2D ratio suits deeper thread engagement requirements\u003c\/li\u003e\n\u003cli\u003eBright finish with 11-7\/8 free coils for consistent coil engagement across the full insert length\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style screw-locking helical coil insert for 5\/16-18 UNC threaded applications requiring a 2-1\/2D length insert in stainless steel parent material or compatible alloys.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation requires a proper HELI-COIL or compatible tangless insert installation tool sized for 5\/16-18 UNC thread. The parent material bore must be drilled and tapped to the correct insert tap size before installation. Ensure the assembly is de-energized and secured before performing thread repair on any mechanical or electrical component. Do not attempt installation without the correct driving tool, as improper installation can damage the insert coils or the parent thread.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 5\/16-18 UNC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Insert Length\u003c\/strong\u003e: 0.781 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength to Diameter Ratio\u003c\/strong\u003e: 2-1\/2D\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Free Coils\u003c\/strong\u003e: 11-7\/8\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\u003eMaximum Locking Torque\u003c\/strong\u003e: 60 in\/lb\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMinimum Breakaway Torque\u003c\/strong\u003e: 7.50 in\/lb\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\u003ch4\u003eStandard Information\u003c\/h4\u003e\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: A3585-5CN781\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HELI-COIL","offers":[{"title":"Default Title","offer_id":52121295094066,"sku":"A3585-5CN781","price":22.15,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/4415a0c18d090a29e3f8de0a567099b1.jpg?v=1790084388","url":"https:\/\/voomisupply.com\/products\/heli-coil-a3585-5cn781-screw-locking-insert-5-16-18-unc","provider":"Voomi Supply","version":"1.0","type":"link"}