{"product_id":"osg-5420400-square-end-mill-5-16-in-4-flute-cobalt","title":"Osg 5420400 Square End Mill 5\/16 in 4 Flute Cobalt","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe OSG 5420400 is a cobalt square end mill designed for milling, slotting, and profiling operations on ferrous and non-ferrous materials. Built from M42 cobalt high-speed steel, it delivers heat resistance and edge retention in demanding cutting conditions. The tool features a 5\/16 inch cutting diameter, a 3\/4 inch length of cut, and a 30-degree right-hand spiral flute geometry that promotes efficient chip evacuation. With four flutes and a right-hand cut, it is suited for finish and semi-finish passes on steel, stainless steel, and cast iron. Machinists and tool-and-die professionals install this end mill in conventional milling machines, CNC machining centers, and knee mills.\u003c\/p\u003e\u003cp\u003eThis end mill is configured as a double-end tool, meaning both ends are usable cutting edges, extending tool life and reducing per-cut cost. The 3\/8 inch shank diameter fits standard ER collets and end mill holders common across most vertical machining setups. It falls within OSG Series 542, a regular-length cobalt end mill line intended for general-purpose shop use. The uncoated finish makes it appropriate for applications where coating compatibility or regrinding is a consideration. Typical applications include shoulder milling, slot milling, and peripheral profiling on workpieces requiring moderate tolerances.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eM42 cobalt construction for elevated heat resistance compared to standard M2 HSS\u003c\/li\u003e\n\u003cli\u003e30-degree helix angle promotes smooth chip flow and reduced cutting forces\u003c\/li\u003e\n\u003cli\u003eFour-flute configuration balances feed rate capacity with surface finish quality\u003c\/li\u003e\n\u003cli\u003eDouble-end design provides two usable cutting ends per tool\u003c\/li\u003e\n\u003cli\u003eUncoated finish supports easy regrinding and broad material compatibility\u003c\/li\u003e\n\u003cli\u003eRight-hand cut and right-hand flute geometry for standard spindle rotation\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement or direct fitment end mill for standard 3\/8 inch end mill holders and ER collet chucks used in vertical mills and CNC machining centers. Part of the OSG Series 542 regular-length cobalt end mill line.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation should be performed by a qualified machinist following shop-standard tool-change procedures. Ensure the spindle is fully stopped and the machine is in an e-stop or locked-out state before changing tooling. Seat the shank fully in the collet or holder and torque the retention nut to the tool holder manufacturer's specification. Verify runout with a dial indicator before beginning a cut, particularly when tight tolerances are required.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMill Diameter\u003c\/strong\u003e: 5\/16 inch (0.3125 inches)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength of Cut\u003c\/strong\u003e: 3\/4 inch (0.7500 inches)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShank Diameter\u003c\/strong\u003e: 3\/8 inch (0.3750 inches)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 3-1\/2 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eNumber of Flutes\u003c\/strong\u003e: 4\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eEnd Mill Material\u003c\/strong\u003e: Cobalt (M42)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHelix Angle\u003c\/strong\u003e: 30 degrees\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlute Type\u003c\/strong\u003e: Spiral\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCutting 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\u003eEnd Configuration\u003c\/strong\u003e: Double End\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoating\u003c\/strong\u003e: Uncoated\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCentercutting\u003c\/strong\u003e: No\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: 542\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\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: 5420400\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"OSG","offers":[{"title":"Default Title","offer_id":51735863001394,"sku":"5420400","price":69.69,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/48baa78a2e930b401e36677bbcee471f.jpg?v=1788774620","url":"https:\/\/voomisupply.com\/products\/osg-5420400-square-end-mill-5-16-in-4-flute-cobalt","provider":"Voomi Supply","version":"1.0","type":"link"}