{"product_id":"heli-coil-7551-2-8-32-unc-prewinder-installation-tool","title":"Heli-coil 7551-2 8-32 Unc Prewinder Installation Tool","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe HELI-COIL 7551-2 is a hand-held prewinder installation tool designed to seat wire thread inserts accurately into prepared threaded holes. Classified as a Type II Prewinder, it accepts both free-running and locking insert styles in the 8-32 UNC thread size. The tool features a prewinder body diameter of 0.375 inches and a spinner diameter of 2.28 inches, giving technicians positive grip and controlled insertion torque without power tools. At 4.625 inches in overall prewinder length and weighing 0.33 pounds, it fits comfortably in a tool bag for bench or field use. Maintenance technicians, aerospace assemblers, and industrial repair professionals rely on this style of tool to install thread inserts correctly on the first attempt.\u003c\/p\u003e\n\u003cp\u003eThis tool is suited for repair and assembly operations where 8-32 UNC threaded holes require insert installation, including stripped fastener repair in aluminum, magnesium, and other soft or worn parent materials. It is commonly used in HVAC equipment assembly, electrical enclosure repair, engine and compressor maintenance, and general industrial fabrication. The prewinder design winds the insert onto the mandrel before insertion, ensuring proper coil alignment and preventing cross-threading during hand installation.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003ePrewinder Type II design winds insert onto mandrel before driving, reducing installation errors\u003c\/li\u003e\n  \u003cli\u003eCompatible with both free-running and locking 8-32 UNC wire thread inserts\u003c\/li\u003e\n  \u003cli\u003ePrewinder body diameter of 0.375 inches for stable tool-to-workpiece contact\u003c\/li\u003e\n  \u003cli\u003eSpinner diameter of 2.28 inches provides leverage for controlled hand torque\u003c\/li\u003e\n  \u003cli\u003eOverall prewinder length of 4.625 inches suits bench and in-place installation\u003c\/li\u003e\n  \u003cli\u003eLightweight at 0.33 pounds for extended use without fatigue\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned for use with 8-32 UNC free-running and locking wire thread inserts. Confirm insert series compatibility with the insert manufacturer before use.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eThis tool is intended for hand installation only  -  do not adapt it to power drivers, as overdriving will damage the insert or parent material. Ensure the receiving hole has been drilled and tapped to the correct specifications for the insert size before use. Wind the insert fully onto the prewinder mandrel prior to engaging the workpiece. After installation, use the appropriate tang break-off tool to remove the driving tang if required by the insert type.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTool Type\u003c\/strong\u003e: Hand Installation Tool, Type II Prewinder\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 8-32\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Standard\u003c\/strong\u003e: UNC\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eInsert Compatibility\u003c\/strong\u003e: Free-Running and Locking\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrewinder Body Diameter\u003c\/strong\u003e: 0.375 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpinner Diameter\u003c\/strong\u003e: 2.28 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrewinder Length\u003c\/strong\u003e: 4.625 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.33 pounds\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: 7551-2\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HELI-COIL","offers":[{"title":"Default Title","offer_id":52076724519218,"sku":"7551-2","price":316.21,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/570eb6f01adfb4399d92fa5ca07e533d.jpg?v=1790052858","url":"https:\/\/voomisupply.com\/products\/heli-coil-7551-2-8-32-unc-prewinder-installation-tool","provider":"Voomi Supply","version":"1.0","type":"link"}