{"product_id":"osg-2940701-spiral-flute-tap-1-4-28-unf-modified-bottoming","title":"Osg 2940701 Spiral Flute Tap 1\/4-28 Unf Modified Bottoming","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe OSG 2940701 is a spiral flute tap designed for cutting internal 1\/4-28 UNF right-hand threads in a variety of ferrous materials. It features a 45-degree helix angle that efficiently evacuates chips upward and out of the hole, making it well suited for blind-hole tapping operations. Manufactured from vanadium high-speed steel and finished with a steam oxide coating, the 2940701 offers improved lubricity and corrosion resistance compared to uncoated HSS taps. The modified bottoming chamfer allows threads to be cut close to the bottom of a blind hole. Overall length is 2.5 inches with a thread limit of H11, indicating a controlled oversize fit for applications requiring a standard tolerance class.\u003c\/p\u003e\n\u003cp\u003eThis tap is intended for use in machine tapping operations across a range of ferrous workpiece materials including alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel. It fits standard tap holders and tapping heads used in machining centers, CNC mills, drill presses, and manual tapping arms. The spiral flute design and 45-degree helix make it particularly effective in blind holes where chip packing is a concern. Machinists and tool-and-die professionals working in production or maintenance environments will find this tap appropriate for precision threading tasks where close thread-limit control is required.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e1\/4-28 UNF right-hand thread form for standard unified fine-pitch applications\u003c\/li\u003e\n  \u003cli\u003e45-degree right-hand spiral flutes for upward chip evacuation in blind holes\u003c\/li\u003e\n  \u003cli\u003eModified bottoming chamfer allows threading close to the bottom of a blind bore\u003c\/li\u003e\n  \u003cli\u003eVanadium high-speed steel construction for durability in ferrous materials including hardened steel\u003c\/li\u003e\n  \u003cli\u003eSteam oxide coating improves lubricity and reduces galling\u003c\/li\u003e\n  \u003cli\u003eH11 thread limit with oversize classification for controlled fit tolerance\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eRated for use in alloy steel, carbon steel, cast iron, stainless steel, die steel, and hardened steel workpieces. Fits standard tap holders sized for a 0.255-inch shank diameter with a 0.191-inch square drive.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eThis tap should be installed and driven by a qualified machinist using appropriate tapping fluid or cutting oil matched to the workpiece material. Always ensure the workpiece is securely fixtured and the tap is properly aligned with the drilled pilot hole before engaging. Consult the tap manufacturer or Machinery Handbook guidelines for correct tap drill size selection for 1\/4-28 UNF threads. Inspect the tap for wear or chipping before each use, and never force a tap that has stalled — back it out to clear chips before continuing.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Size\u003c\/strong\u003e: 1\/4-28 UNF\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Standard\u003c\/strong\u003e: UNF\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThreads per Inch\u003c\/strong\u003e: 28\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Direction\u003c\/strong\u003e: Right Hand\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\u003eFlute Style\u003c\/strong\u003e: Spiral\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eHelix Angle\u003c\/strong\u003e: 45 degrees\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eChamfer\u003c\/strong\u003e: Modified Bottoming\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Limit\u003c\/strong\u003e: H11\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOversize\u003c\/strong\u003e: Yes\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: Steam Oxide\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 2.5 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eThread Length\u003c\/strong\u003e: 0.397 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShank Diameter\u003c\/strong\u003e: 0.255 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNeck Length\u003c\/strong\u003e: 0.996 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSquare Length\u003c\/strong\u003e: 0.3125 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSquare Size\u003c\/strong\u003e: 0.191 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoolant Through\u003c\/strong\u003e: No\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.03 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: 290\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: 2940701\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"OSG","offers":[{"title":"Default Title","offer_id":51755481596210,"sku":"2940701","price":47.43,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/c13e07fa4e9f6807f8dbad2e72d0c55c.jpg?v=1788955444","url":"https:\/\/voomisupply.com\/products\/osg-2940701-spiral-flute-tap-1-4-28-unf-modified-bottoming","provider":"Voomi Supply","version":"1.0","type":"link"}