{"product_id":"hertel-04139309-cobalt-jobber-drill-bit-letter-c","title":"Hertel 04139309 Cobalt Jobber Drill Bit Letter C","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe HERTEL 04139309 is a cobalt jobber-length drill bit sized to Letter C (0.2420 inches) for demanding holemaking applications in metal and hard materials. Built from heavy-duty cobalt steel with an oxide and TiN coating, it delivers extended tool life in ferrous and abrasive workpiece materials. The 135-degree split point reduces walking on entry and lowers thrust force, making it well suited for work on curved or irregular surfaces. The right-hand spiral flute with a regular helix evacuates chips efficiently. Overall length is 4 inches with a 2.75-inch flute length. Used by machinists, millwrights, and maintenance technicians working with drill presses, lathes, and hand-held power tools.\u003c\/p\u003e\u003cp\u003eThis drill bit is designed for general holemaking in production and maintenance environments. The straight-cylindrical shank seats securely in standard three-jaw chucks and keyless chucks without adapter sleeves. The web-thinned, tapered-web construction keeps cutting forces manageable when drilling steel, stainless, cast iron, and similarly hard materials. It is sold individually and is a practical stock item for tool cribs, job boxes, and machine shop consumable inventories.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eLetter C sizing at 0.2420 inches decimal equivalent for precise hole sizing\u003c\/li\u003e\n\u003cli\u003eCobalt construction with oxide and TiN coating for heat and wear resistance in hard metals\u003c\/li\u003e\n\u003cli\u003e135-degree split point reduces thrust and minimizes bit walking on entry\u003c\/li\u003e\n\u003cli\u003eRight-hand regular spiral flute with web thinning for efficient chip evacuation\u003c\/li\u003e\n\u003cli\u003eStraight-cylindrical shank fits standard drill chucks without adapters\u003c\/li\u003e\n\u003cli\u003eHeavy-duty grade rated for continuous production and maintenance drilling\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement jobber drill bit compatible with any drill press, CNC machine, lathe tailstock, or hand-held power drill accepting a straight-cylindrical shank of 0.2420 inches diameter.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation is performed by machinists and maintenance technicians. Secure the shank fully in the chuck and verify runout before drilling. Always power down and lock out the machine before changing bits. Use cutting fluid or coolant appropriate to the workpiece material to protect the coating and extend tool life; coolant-through is not supported by this bit.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Letter)\u003c\/strong\u003e: C\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Decimal Inch)\u003c\/strong\u003e: 0.2420 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Material\u003c\/strong\u003e: Cobalt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoating\/Finish\u003c\/strong\u003e: Oxide and TiN\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Point Angle\u003c\/strong\u003e: 135 degrees\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePoint Type\u003c\/strong\u003e: Split\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlute Type\u003c\/strong\u003e: Spiral\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSpiral Type\u003c\/strong\u003e: Regular\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCutting Direction\u003c\/strong\u003e: Right Hand\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlute Length\u003c\/strong\u003e: 2.75 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 4 inches\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: 0.2420 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeb Configuration\u003c\/strong\u003e: Tapered\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeb Thinning\u003c\/strong\u003e: Web-Thinned\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDouble Margin\u003c\/strong\u003e: No\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoolant Through\u003c\/strong\u003e: No\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Grade\u003c\/strong\u003e: Heavy Duty\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries\u003c\/strong\u003e: Jobber\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.48 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: HERTEL\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 04139309\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HERTEL","offers":[{"title":"Default Title","offer_id":51749277040946,"sku":"04139309","price":14.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/5370a724cc13005dbf9d1b57dc62d75d.jpg?v=1788903930","url":"https:\/\/voomisupply.com\/products\/hertel-04139309-cobalt-jobber-drill-bit-letter-c","provider":"Voomi Supply","version":"1.0","type":"link"}