{"product_id":"osg-5420300-square-end-mill-1-4-in-4-flute-cobalt-double-end","title":"Osg 5420300 Square End Mill 1\/4 in 4 Flute Cobalt Double End","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe OSG 5420300 is a cobalt square end mill designed for milling operations in metalworking and machining environments. Built from M42 cobalt high-speed steel, it delivers heat and wear resistance suited for cutting ferrous metals, stainless steels, and other tough materials. The tool measures 0.25 inches in cutting diameter with a 0.625-inch length of cut, a 0.375-inch shank diameter, and a 3.375-inch overall length. With 4 spiral flutes at a 30-degree helix angle and right-hand cut and flute direction, it produces clean, efficient chip evacuation during side milling and profiling passes.\u003c\/p\u003e\u003cp\u003eThis end mill is used in manual knee mills, CNC machining centers, and drill press setups for slot milling, profiling, and light pocket work on harder workpiece materials. The double-end design provides two usable cutting ends, extending tool life and reducing per-cut tooling cost. It fits production and tool room environments where M42 cobalt construction is preferred over carbide for interrupted cuts or setups with less-than-rigid fixturing. The Series 542 designation identifies it within OSGs standard cobalt end mill lineup.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eM42 cobalt construction for elevated heat resistance compared to standard HSS\u003c\/li\u003e\n\u003cli\u003eDouble-end design provides two cutting ends per tool\u003c\/li\u003e\n\u003cli\u003e4 spiral flutes with 30-degree helix angle for efficient chip flow\u003c\/li\u003e\n\u003cli\u003eRight-hand cut and right-hand flute direction for standard spindle operation\u003c\/li\u003e\n\u003cli\u003eUncoated finish suitable for use with cutting fluids on ferrous materials\u003c\/li\u003e\n\u003cli\u003eRegular length designation fits standard toolholders without extended-reach concerns\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement or direct-use cutting tool for machining centers and manual mills accepting a 3\/8-inch straight shank end mill holder or collet.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation is performed by machinists using an appropriate collet chuck or end mill holder rated for the 0.375-inch shank diameter. Ensure the spindle is fully stopped and locked out before installing or removing the tool. Verify runout with a dial indicator after seating in the holder, as excessive runout accelerates flute wear. This tool is not center-cutting and should not be used for direct plunge entry into solid material.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMill Diameter\u003c\/strong\u003e: 0.25 inches (1\/4 inch)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLength of Cut\u003c\/strong\u003e: 0.625 inches (5\/8 inch)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eShank Diameter\u003c\/strong\u003e: 0.375 inches (3\/8 inch)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 3.375 inches (3-3\/8 inch)\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\u003eFlute Type\u003c\/strong\u003e: Spiral\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHelix Angle\u003c\/strong\u003e: 30 degrees\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 Type\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: 5420300\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"OSG","offers":[{"title":"Default Title","offer_id":51738752614706,"sku":"5420300","price":70.11,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/fa202fde8f29eb94890a370d0fac5fa5.jpg?v=1788803881","url":"https:\/\/voomisupply.com\/products\/osg-5420300-square-end-mill-1-4-in-4-flute-cobalt-double-end","provider":"Voomi Supply","version":"1.0","type":"link"}