{"product_id":"hertel-42201-21-64-inch-cobalt-screw-machine-drill-bit","title":"Hertel 42201 21\/64 Inch Cobalt Screw Machine Drill Bit","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe HERTEL 42201 is a screw machine length cobalt drill bit designed for demanding metal cutting applications. Built from M35 cobalt steel with an oxide straw finish, it delivers the heat resistance and hardness retention needed when drilling tough ferrous materials. At 21\/64 inch (0.3281 inches) in diameter with a 135-degree split point, it starts on contact with minimal walking and reduces the thrust required to break through. The overall length is 2.9375 inches with a spiral flute length of 1.6875 inches. Licensed HVAC technicians, machinists, and industrial tradespeople reach for cobalt bits when carbon steel or standard high-speed steel falls short on hardened stock.\u003c\/p\u003e\u003cp\u003eThis bit is suited for production and maintenance drilling in hardened materials, heat-treatable alloyed steels, stainless steel, and titanium alloy. The screw machine length — shorter than a jobber bit — provides added rigidity and reduced deflection in drill press, turret lathe, and CNC mill applications where tool runout must be minimized. The 3xD flute-to-diameter ratio supports efficient chip evacuation in the short-bore geometries typical of screw machine work.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eM35 cobalt steel construction for elevated heat resistance during high-speed drilling\u003c\/li\u003e\n\u003cli\u003e135-degree split point for self-centering starts and reduced feed pressure\u003c\/li\u003e\n\u003cli\u003eOxide straw finish provides mild lubricity and corrosion resistance\u003c\/li\u003e\n\u003cli\u003eScrew machine (stub) length adds rigidity and reduces deflection versus jobber-length bits\u003c\/li\u003e\n\u003cli\u003eRegular spiral flute with 3xD ratio supports consistent chip evacuation\u003c\/li\u003e\n\u003cli\u003eNo coolant-through design — suited for external coolant or dry drilling setups\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eDesigned as an OEM-style replacement or production-grade addition for any 21\/64 inch drill chuck application; fits standard drill press, lathe turret, and CNC spindle setups accepting bits in the 0.3000 to 0.3500 inch decimal inch range.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation is performed by machinists, tool-and-die tradespeople, or maintenance technicians. Secure the bit in a properly sized chuck and confirm runout before drilling. When working with stainless steel or titanium alloy, use appropriate cutting fluid to manage heat buildup and extend tool life. Inspect the cutting edges before each use and replace if chipping or heat discoloration at the tip is observed.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Inch)\u003c\/strong\u003e: 21\/64\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Size (Decimal Inch)\u003c\/strong\u003e: 0.3281 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 2.9375 inches (2-15\/16 inches)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFlute Length\u003c\/strong\u003e: 1.6875 inches (1-11\/16 inches)\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\u003eTool Material\u003c\/strong\u003e: Cobalt\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial Grade\u003c\/strong\u003e: M35\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCoating\/Finish\u003c\/strong\u003e: Oxide Straw\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\u003eFlute By Diameter Ratio\u003c\/strong\u003e: 3xD\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: Hardened Materials, Heat-Treatable Alloyed Steels, Stainless Steel, Titanium Alloy\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrill Bit Size Range (Decimal Inch)\u003c\/strong\u003e: 0.3000 to 0.3500 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.1 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: 42201\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"HERTEL","offers":[{"title":"Default Title","offer_id":51748260086066,"sku":"42201","price":16.66,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/5ca6ff36af0982b6bea5849f9bc04bfc.jpg?v=1788891292","url":"https:\/\/voomisupply.com\/products\/hertel-42201-21-64-inch-cobalt-screw-machine-drill-bit","provider":"Voomi Supply","version":"1.0","type":"link"}