{"product_id":"heli-coil-5905-5-spiral-flute-sti-tap-5-16-18-unc","title":"Heli-coil 5905-5 Spiral Flute Sti Tap 5\/16-18 Unc","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe HELI-COIL 5905-5 is a spiral flute STI (Screw Thread Insert) tap designed to cut threads for helical wire thread inserts in a single pass. Made from high-speed steel with a bright finish, this tap produces a 5\/16-18 UNC thread with a 3B class of fit, suited to precision insert installation. The bottoming chamfer allows threading close to the bottom of a blind hole, making it the right choice when full thread depth is required right to the base of the bore. With 3 right-hand spiral flutes and an H3 thread limit, it delivers accurate, consistent thread form for insert prep work across a range of base materials.\u003c\/p\u003e\u003cp\u003eThis tap is used in maintenance, repair, and manufacturing applications where damaged or stripped threads are being reclaimed using helical wire inserts. It is the correct first step before installing a 5\/16-18 UNC HELI-COIL or compatible wire thread insert. Typical install scenarios include engine component repair, equipment maintenance in industrial settings, and field repair of tapped holes in aluminum, cast iron, or steel. It is operated by hand tap wrench or low-speed machine tapping on a drill press or tapping machine.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e5\/16-18 UNC thread form with H3 thread limit for accurate STI oversized thread profile\u003c\/li\u003e\n\u003cli\u003eBottoming chamfer allows threading to the base of blind holes\u003c\/li\u003e\n\u003cli\u003e3 right-hand spiral flutes for chip evacuation during tapping\u003c\/li\u003e\n\u003cli\u003eHigh-speed steel construction for durability across common base materials\u003c\/li\u003e\n\u003cli\u003e3B class of fit ensures proper engagement geometry for wire thread inserts\u003c\/li\u003e\n\u003cli\u003eOverall length of 2-15\/16 inches with a 0.381-inch shank diameter for standard tap wrench or holder compatibility\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned for use in STI tapping operations prior to installation of 5\/16-18 UNC helical wire thread inserts. Intended for use with compatible HELI-COIL or equivalent insert installation systems requiring a 3B class of fit thread.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eThis tap is installed by a machinist, maintenance technician, or qualified tradesperson using a tap wrench or low-speed tapping setup. Always ensure the workpiece is secured and the bore is drilled to the correct STI drill size before tapping. Use appropriate cutting fluid for the base material to extend tap life and improve thread quality. Do not use excessive force or high spindle speeds, as HSS taps are susceptible to breakage under torsional overload.\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\u003eNumber of Flutes\u003c\/strong\u003e: 3\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlute Direction\u003c\/strong\u003e: Right Hand\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eChamfer Type\u003c\/strong\u003e: Bottoming\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Standard\u003c\/strong\u003e: UNC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClass of Fit\u003c\/strong\u003e: 3B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Limit\u003c\/strong\u003e: H3\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 2-15\/16 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Length\u003c\/strong\u003e: 1-1\/4 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShank Diameter\u003c\/strong\u003e: 0.381 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: High-Speed Steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFinish\u003c\/strong\u003e: Bright\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUNSPSC Code\u003c\/strong\u003e: 23241600\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: 5905-5\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HELI-COIL","offers":[{"title":"Default Title","offer_id":51972414800178,"sku":"5905-5","price":87.12,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/e58855302fc260315cdee54d394ec143.jpg?v=1789968052","url":"https:\/\/voomisupply.com\/products\/heli-coil-5905-5-spiral-flute-sti-tap-5-16-18-unc","provider":"Voomi Supply","version":"1.0","type":"link"}