Cleveland C70191 Cobalt Jobber Drill Bit No 58 0.0420 in

Product Description

The CLEVELAND C70191 is a cobalt jobber-length drill bit in wire gauge size No. 58 (0.0420 inches decimal), designed for precision drilling in tough and abrasive materials. Built from M42 cobalt high-speed steel and finished with a gold oxide coating, this bit resists heat buildup and maintains cutting edge integrity under demanding conditions. The 135-degree split point reduces walking and allows fast penetration without a center punch. Overall length is 1-5/8 inches with a flute length of 11/16 inches. It is suited for use by machinists, maintenance technicians, and trade professionals requiring accurate small-diameter hole production.

This drill bit is engineered for use in aluminum and similar non-ferrous or light-ferrous workpiece materials. The regular spiral flute geometry promotes efficient chip evacuation in shallow-depth holes typical of sheet metal, brackets, and component drilling applications. The straight-cylindrical shank (0.0420 inches diameter) fits standard 3-jaw drill chucks found on benchtop drill presses, hand drills, and CNC spindles. The Series 2213 designation and NAS 907 Type J standard make this a recognized choice for aerospace-adjacent and precision manufacturing environments. Each package contains one bit.

Key Features

• M42 cobalt HSS construction for extended tool life in abrasive and work-hardening materials
• Gold oxide coating reduces friction and dissipates heat at the cutting zone
• 135-degree split point for self-centering entry and reduced thrust force
• Web-thinned, tapered web configuration improves chip flow and reduces cutting load
• Right-hand cut with 2-flute regular spiral geometry for consistent chip evacuation
• Meets NAS 907 Type J standard for heavy-duty precision drilling applications

Compatibility

Designed as an OEM-style replacement or direct-use jobber drill bit for any standard 3-jaw drill chuck accepting a 0.0420-inch straight-cylindrical shank, consistent with Series 2213 No. 58 wire gauge tooling.

Installation Notes

Install this bit into a properly sized drill chuck and tighten securely before operation. Always wear appropriate eye protection and secure the workpiece before drilling. Use a compatible cutting fluid or lubricant when drilling metals to extend bit life and maintain dimensional accuracy. Replace the bit if the cutting edges show visible wear, chipping, or if hole quality degrades.