{"product_id":"heli-coil-7551-8-thread-insert-tool-1-2-13-unc-prewinder","title":"Heli-coil 7551-8 Thread Insert Tool 1\/2-13 Unc Prewinder","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe HELI-COIL 7551-8 is a hand installation tool designed for installing wire thread inserts into 1\/2-13 UNC tapped holes. Built as a Type II Prewinder, it compresses the insert onto the mandrel before driving it into the prepared bore, reducing installation errors and cross-threading. The prewinder body measures 7\/8 inch in diameter, with a spinner diameter of 3-23\/32 inches and a prewinder length of 1\/2 inch. The tool weighs 0.83 pounds, making it easy to handle in tight work areas. Machinists, maintenance technicians, and field service professionals use this tool wherever threaded repair or original installation of wire thread inserts is required.\u003c\/p\u003e\n\u003cp\u003eThis tool is suited for repair and production applications involving 1\/2-13 UNC threaded bores in metal components. Typical use cases include restoring stripped threads in aluminum, cast iron, or steel housings found in HVAC equipment, pump bodies, compressor casings, and industrial machinery. The prewinder design supports both free-running and locking insert types, giving the technician flexibility depending on whether vibration resistance is required in the final assembly.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eType II Prewinder design compresses insert before installation, reducing installation errors\u003c\/li\u003e\n  \u003cli\u003eCompatible with both free-running and locking wire thread insert styles\u003c\/li\u003e\n  \u003cli\u003eSized for 1\/2-13 UNC thread standard\u003c\/li\u003e\n  \u003cli\u003ePrewinder body diameter of 7\/8 inch fits standard tooling clearances\u003c\/li\u003e\n  \u003cli\u003eSpinner diameter of 3-23\/32 inches provides mechanical advantage for hand torquing\u003c\/li\u003e\n  \u003cli\u003eLightweight at 0.83 pounds for comfortable single-hand operation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned for use with free-running and locking wire thread inserts in 1\/2-13 UNC thread size. Confirm insert manufacturer and series before use to ensure mandrel thread pitch matches the insert specification.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation should be performed by a qualified machinist or maintenance technician familiar with thread insert repair procedures. Verify that the tapped hole meets the required tap drill diameter and depth specifications for the insert size before using this tool. No power source is required; this is a hand-operated tool. Avoid applying excessive downward force during spinning, as this can distort the insert or damage the prewinder mandrel.\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: 1\/2-13\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: 7\/8 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSpinner Diameter\u003c\/strong\u003e: 3-23\/32 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrewinder Length\u003c\/strong\u003e: 1\/2 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.83 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eUNSPSC Code\u003c\/strong\u003e: 23291800\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: 7551-8\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HELI-COIL","offers":[{"title":"Default Title","offer_id":52023358882098,"sku":"7551-8","price":160.74,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/a8e5e4f8becbfd8de76402b17ee991c4.jpg?v=1790013991","url":"https:\/\/voomisupply.com\/products\/heli-coil-7551-8-thread-insert-tool-1-2-13-unc-prewinder","provider":"Voomi Supply","version":"1.0","type":"link"}