Precision Twist Drill 5998195 Cobalt Jobber Drill 33/64

Product Description

The PRECISION TWIST DRILL 5998195 is a cobalt jobber-length drill bit designed for heavy-duty drilling applications in steel and other demanding workpiece materials. Sized at 33/64 inch (0.5156 inch decimal), it features a 135-degree split point with web thinning for fast penetration and reduced walking on entry. The straw oxide finish provides mild lubricity and heat resistance. At 6.625 inches overall length with a 4.8125-inch flute length, this bit is built to handle deep-hole drilling within its 9xD depth-to-diameter ratio. It is well suited for licensed machinists, maintenance mechanics, and metalworking tradespeople working with ferrous and non-ferrous stock.

This cobalt drill bit is intended for general-purpose drilling in steel, cast iron, aluminum, and similar materials, meeting ANSI and NAS 907 standards. The Series R10CO-R15CO-R18CO designation places it in a heavy-duty cobalt line built for shop floor and field use. The straight cylindrical shank fits standard drill chucks without adapters, making it compatible with bench drill presses, hand drills, and magnetic base drills commonly used in HVAC, mechanical, and electrical rough-in work where steel drilling is required.

Key Features

• Cobalt high-speed steel construction for heat and wear resistance when drilling hard metals
• 135-degree split point with web thinning reduces thrust and minimizes drill walking
• Straw oxide finish adds lubricity and extends tool life in ferrous materials
• Regular spiral flute geometry promotes efficient chip evacuation
• Straight cylindrical shank fits standard drill chucks directly
• Meets ANSI and NAS 907 specifications for dimensional accuracy and performance

Compatibility

Part of the Precision Twist Drill Series R10CO-R15CO-R18CO cobalt jobber drill line, designed as a general-purpose OEM-style replacement or direct-use bit for drilling steel and similar primary workpiece materials in maintenance, fabrication, and construction applications.

Installation Notes

Installation and use of this bit should be performed by a qualified machinist or tradesperson familiar with metal drilling procedures. Secure the workpiece firmly before drilling and ensure the drill chuck is properly tightened to the rated shank diameter. Apply appropriate cutting fluid when drilling steel to reduce heat buildup and extend bit life. Do not exceed the rated maximum drilling depth of 4.8125 inches for this bit diameter.