{"product_id":"hertel-66691338-screw-machine-drill-bit-letter-e-cobalt","title":"Hertel 66691338 Screw Machine Drill Bit Letter E Cobalt","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe HERTEL 66691338 is a screw machine length drill bit designed for high-production drilling in metal fabrication, machining, and maintenance applications. Built from cobalt steel with a titanium nitride (TiN) coating, the bit delivers extended tool life and heat resistance in tough materials including stainless steel, cast iron, and high-strength alloys. The 135-degree split point reduces thrust and walking on entry, eliminating the need for a center punch on most surfaces. At 2.5 inches overall length, the screw machine format provides added rigidity compared to jobber-length bits, making it well suited for drill press and CNC applications where runout and deflection are concerns.\u003c\/p\u003e\u003cp\u003eThis bit is sized at Letter E, equivalent to 0.2500 inch decimal, and fits standard straight-cylindrical shank chucks. It is commonly used in production drilling on drill presses, turret lathes, machining centers, and hand-held pneumatic drills where short, stiff tooling reduces breakage. The heavy-duty grade designation and web-thinned, parallel web configuration make it appropriate for repetitive through-hole and blind-hole operations in metal shop and industrial maintenance environments. Machinists, tool and die workers, and industrial maintenance technicians are the primary installers and users.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eCobalt steel construction with TiN coating for heat and wear resistance in ferrous and hard alloys\u003c\/li\u003e\n\u003cli\u003e135-degree split point reduces entry thrust and minimizes drill walking without a center punch\u003c\/li\u003e\n\u003cli\u003eScrew machine length (2.5 inches OAL) provides greater rigidity than jobber-length bits for precision drilling\u003c\/li\u003e\n\u003cli\u003eWeb-thinned parallel web reduces cutting resistance and improves chip evacuation\u003c\/li\u003e\n\u003cli\u003eRight-hand spiral flute geometry for standard clockwise rotation in conventional drilling setups\u003c\/li\u003e\n\u003cli\u003eStraight-cylindrical shank fits standard three-jaw chucks and collet systems\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned for use in any drill press, CNC machining center, turret lathe, or hand-held drill accepting a 0.2500-inch straight-cylindrical shank. Suitable for drilling steel, stainless steel, cast iron, and similar hard materials requiring heavy-duty cobalt tooling.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eSecure the shank fully in the chuck and verify concentricity before drilling to minimize runout. Always power down and lock out the machine before changing tooling per applicable OSHA lockout\/tagout procedures. Use appropriate cutting fluid or coolant for the workpiece material to extend tool life, even though this bit does not support coolant-through delivery. Inspect the cutting edges and TiN coating before each use and discard bits showing chipping or coating failure to avoid workpiece damage.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\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\u003eTool Material\u003c\/strong\u003e: Cobalt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoating\/Finish\u003c\/strong\u003e: TiN (Titanium Nitride)\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\u003eOverall Length\u003c\/strong\u003e: 2.5 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlute Length\u003c\/strong\u003e: 1.375 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: 0.2500 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCutting Direction\u003c\/strong\u003e: Right Hand\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\u003eWeb Configuration\u003c\/strong\u003e: Parallel, Web-Thinned\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\u003eWeight\u003c\/strong\u003e: 0.1 pounds\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUNSPSC Code\u003c\/strong\u003e: 23241635\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: 66691338\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HERTEL","offers":[{"title":"Default Title","offer_id":51741251830066,"sku":"66691338","price":14.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/0696dc21f2427062ce17b9785ca41e3a.jpg?v=1788830338","url":"https:\/\/voomisupply.com\/products\/hertel-66691338-screw-machine-drill-bit-letter-e-cobalt","provider":"Voomi Supply","version":"1.0","type":"link"}