{"product_id":"osg-15250005-cobalt-jobber-drill-bit-letter-e-1-4-inch","title":"Osg 15250005 Cobalt Jobber Drill Bit Letter E 1\/4 Inch","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe OSG 15250005 is a cobalt jobber-length drill bit sized at Letter E (0.2500 inches \/ 6.35 mm) with a titanium nitride (TiN) coating for extended tool life in demanding applications. It features a 130-degree R-thinned point that reduces thrust and promotes self-centering at entry, and a regular spiral flute geometry for efficient chip evacuation. Overall length is 4.5625 inches with a 2.75-inch flute length. The straight-cylindrical shank measures 0.25 inches in diameter and 1.5625 inches in length. Licensed tradespeople and machining professionals in fabrication, mechanical contracting, and industrial maintenance use this bit for precision drilling in steel and alloy steel.\u003c\/p\u003e\n\u003cp\u003eThe OSG 15250005 is suited for drilling blind holes, cross holes, and through holes in steel and alloy steel workpieces. It carries a Primary Workpiece Material Code of P, which corresponds to ISO-designation ferrous materials including carbon steel, alloy steel, and tool steel. Typical applications include structural drilling, mechanical assembly, and maintenance repair work where a high-performance cobalt bit is required to handle work-hardening materials or interrupted cuts. The bit is designed for use without coolant-through capability, so external coolant or cutting fluid is recommended when drilling harder alloys.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eCobalt substrate with TiN coating for increased wear resistance and heat tolerance in ferrous materials\u003c\/li\u003e\n  \u003cli\u003e130-degree R-thinned split point reduces walking and lowers entry thrust, eliminating the need for a center punch on most setups\u003c\/li\u003e\n  \u003cli\u003eRegular spiral flute with tapered web configuration promotes consistent chip flow and reduces clogging\u003c\/li\u003e\n  \u003cli\u003eStraight-cylindrical shank fits standard 3-jaw drill chucks without adapters\u003c\/li\u003e\n  \u003cli\u003eRight-hand cutting direction; compatible with standard forward-rotation drilling equipment\u003c\/li\u003e\n  \u003cli\u003eDiameter tolerance of +0 to -0.022 mm for close-tolerance hole sizing\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned as an OEM-style high-performance replacement or service bit for applications requiring a Letter E (1\/4 inch) jobber-length drill bit in standard straight-shank drill chucks on benchtop drill presses, hand drills, and CNC drilling machines. Part of the OSG Series 1500 product family.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation is performed by qualified machinists or tradespeople familiar with rotating cutting tools. Secure the straight-cylindrical shank fully into the chuck jaws and tighten per the chuck manufacturer's guidance before starting the spindle. Apply an appropriate cutting fluid or external coolant when drilling steel or alloy steel to manage heat buildup, as this bit does not support coolant-through delivery. Inspect the cutting edges and TiN coating condition before each use; a worn or chipped tip will compromise hole tolerance and should be replaced or resharpened by a qualified tool grinding service.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Inch)\u003c\/strong\u003e: 1\/4 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Letter)\u003c\/strong\u003e: E\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Decimal Inch)\u003c\/strong\u003e: 0.2500 inches\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (mm)\u003c\/strong\u003e: 6.35 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrill Bit Material\u003c\/strong\u003e: Cobalt\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFinish \/ Coating\u003c\/strong\u003e: Titanium Nitride (TiN)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDrill Point Angle\u003c\/strong\u003e: 130 degrees\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePoint Type\u003c\/strong\u003e: R-Thinned\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eWeb Configuration\u003c\/strong\u003e: Tapered\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlute Type\u003c\/strong\u003e: Spiral (Regular)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eNumber of Flutes\u003c\/strong\u003e: 2\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCutting Direction\u003c\/strong\u003e: Right Hand\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length (Inch)\u003c\/strong\u003e: 4.5625 inches (4-9\/16 inches)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eOverall Length (mm)\u003c\/strong\u003e: 115.00 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlute Length (Inch)\u003c\/strong\u003e: 2.75 inches (2-3\/4 inches)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFlute Length (mm)\u003c\/strong\u003e: 69.00 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShank Type\u003c\/strong\u003e: Straight-Cylindrical\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShank Diameter\u003c\/strong\u003e: 1\/4 inch\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eShank Length\u003c\/strong\u003e: 1.5625 inches (1-9\/16 inches)\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eDiameter Tolerance\u003c\/strong\u003e: +0 to -0.022 mm\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCoolant Through\u003c\/strong\u003e: No\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePrimary Workpiece Material\u003c\/strong\u003e: Steel, Alloy Steel\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eTool Application\u003c\/strong\u003e: Blind Hole, Cross Hole, Drilling, Self-Centering\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: 1500\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Weight\u003c\/strong\u003e: 0.055 pounds\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003ePackage Quantity\u003c\/strong\u003e: 1\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: 15250005\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"OSG","offers":[{"title":"Default Title","offer_id":51731326697778,"sku":"15250005","price":78.48,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/fc448e0055271dca582a6002919ce324.jpg?v=1788729734","url":"https:\/\/voomisupply.com\/products\/osg-15250005-cobalt-jobber-drill-bit-letter-e-1-4-inch","provider":"Voomi Supply","version":"1.0","type":"link"}