{"product_id":"osg-2957400-spiral-flute-tap-3-8-16-unc-2-flute-modified-bottoming","title":"Osg 2957400 Spiral Flute Tap 3\/8-16 Unc 2 Flute Modified Bottoming","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe OSG 2957400 is a spiral flute tap designed to cut 3\/8-16 UNC internal threads in production and maintenance machining applications. Built from vanadium high-speed steel with a bright, uncoated finish, this tap runs a 50-degree helix angle that efficiently evacuates chips up and out of the hole during the threading operation. The modified bottoming chamfer allows the tap to thread close to the bottom of a blind hole while still providing enough lead to start cleanly. At 2.938 inches overall length with an H3 thread limit, it holds a 3B class of fit across a consistent tolerance window.\u003c\/p\u003e\n\u003cp\u003eThis tap is suited for threading aluminum and similarly machinable non-ferrous materials in blind-hole applications where chip evacuation is critical. The spiral flute geometry makes it a practical choice for CNC tapping cycles and hand tapping operations where broken taps from chip packing are a concern. It is a single-piece, right-hand thread, right-hand flute tool sold individually. Machinists, toolroom technicians, and maintenance mechanics are the primary users of this type of tap in both shop and field contexts.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e3\/8-16 UNC thread form, right-hand thread and right-hand flute direction\u003c\/li\u003e\n  \u003cli\u003eModified bottoming chamfer for threading near the bottom of blind holes\u003c\/li\u003e\n  \u003cli\u003e50-degree helix angle promotes upward chip evacuation in blind-hole tapping\u003c\/li\u003e\n  \u003cli\u003eVanadium high-speed steel construction for wear resistance in aluminum and soft metals\u003c\/li\u003e\n  \u003cli\u003eH3 thread limit, 3B class of fit for standard tolerance internal threads\u003c\/li\u003e\n  \u003cli\u003eBright, uncoated finish — no coating buildup concerns on regrind\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned for use in standard 3\/8-16 UNC blind-hole tapping applications, particularly in aluminum workpieces. Compatible with tap handles, tapping heads, and CNC spindles accepting the Series 295 shank profile with a 0.381-inch shank diameter and 0.286-inch square drive.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eThis tap is installed by licensed machinists or qualified toolroom personnel following standard threading practices. Secure the workpiece and verify correct tap drill size for 3\/8-16 UNC before starting. Use appropriate tapping fluid or cutting oil for the workpiece material to extend tool life and improve thread finish. Inspect the tap for chipping or wear before each use and never force a tap that has stopped advancing, as spiral flute taps in blind holes can break under side load if chips pack the flutes.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 3\/8-16 UNC\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Standard\u003c\/strong\u003e: UNC\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Flutes\u003c\/strong\u003e: 2\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlute Style\u003c\/strong\u003e: Spiral\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHelix Angle\u003c\/strong\u003e: 50 degrees\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChamfer\u003c\/strong\u003e: Modified Bottoming\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\u003eThread Direction\u003c\/strong\u003e: Right Hand\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlute Direction\u003c\/strong\u003e: Right Hand\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial\u003c\/strong\u003e: Vanadium High-Speed Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoating\/Finish\u003c\/strong\u003e: Bright\/Uncoated\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 2.938 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Length\u003c\/strong\u003e: 0.5 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNeck Length\u003c\/strong\u003e: 1.251 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\u003eSquare Size\u003c\/strong\u003e: 0.286 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSquare Length\u003c\/strong\u003e: 0.4375 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThreads per Inch\u003c\/strong\u003e: 16\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoolant Through\u003c\/strong\u003e: No\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eMaterial Application\u003c\/strong\u003e: Aluminum\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: 295\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.073 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: OSG\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 2957400\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"OSG","offers":[{"title":"Default Title","offer_id":51737349718322,"sku":"2957400","price":66.54,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/f6b777b88f0e75a36908c2dcac070805.jpg?v=1788787438","url":"https:\/\/voomisupply.com\/products\/osg-2957400-spiral-flute-tap-3-8-16-unc-2-flute-modified-bottoming","provider":"Voomi Supply","version":"1.0","type":"link"}