Precision Twist Drill 5998201 Cobalt Jobber Drill 37/64in

Product Description

The PRECISION TWIST DRILL 5998201 is a cobalt jobber-length drill bit designed for heavy-duty drilling in steel and other demanding workpiece materials. It features a 37/64-inch (0.5781-inch) diameter, a 135-degree split point with web thinning for reduced thrust and self-centering entry, and a straw oxide finish that provides lubricity and mild heat resistance. The straight shank and regular spiral flute geometry make it compatible with standard drill chucks across a wide range of drill presses, lathes, and hand-held equipment. This bit is suited for machinists, maintenance technicians, and metalworking tradespeople who require consistent hole quality in ferrous and non-ferrous metals.

This jobber drill is built for general-purpose metal drilling applications including structural steel, alloy steel, cast iron, non-ferrous alloys, and heat-resistant superalloys, reflected in its P, M, K, N, and S material group ratings. With an overall length of 6-5/8 inches and a flute length of 4-13/16 inches, it handles standard depth holes in production and maintenance environments. It conforms to ANSI standards and the NAS 907 specification, making it appropriate for aerospace and industrial fabrication work where dimensional and tolerance requirements are strict.

Key Features

• Cobalt high-speed steel construction for improved heat resistance in hard and abrasive materials
• 135-degree split point with web thinning reduces walking and lowers required feed force
• Straw oxide finish provides surface lubricity and corrosion resistance during storage and use
• Regular spiral flute with tapered web configuration promotes efficient chip evacuation
• Right-hand cutting direction, straight cylindrical shank fits standard drill chucks without adapters
• Meets ANSI standards and NAS 907 specification for dimensional accuracy

Compatibility

Part of the R10CO-R15CO-R18CO series. Designed as a general-purpose cobalt jobber drill for use in standard drill chucks and compatible with typical drill press, lathe turret, and hand-drill setups. No coolant-through capability; suitable for external coolant or dry drilling applications.

Installation Notes

Installation and use should be performed by qualified machinists or metalworking technicians familiar with speeds and feeds for cobalt tooling. Secure the straight shank firmly in a calibrated drill chuck and verify runout before beginning a production run. Always wear appropriate eye protection and secure the workpiece before drilling. Do not exceed the recommended maximum drilling depth of 4-13/16 inches for this bit length.