Precision Twist Drill 5997775 Cobalt Jobber Drill Bit

Product Description

The PRECISION TWIST DRILL 5997775 is a wire-size No. 4 cobalt jobber-length drill bit engineered for heavy-duty drilling in ferrous and non-ferrous metals. Ground to a 135-degree split point with web thinning, it cuts fast and self-centers without a pilot hole. The cobalt high-speed steel construction provides heat resistance and edge retention beyond standard HSS, making it well suited for stainless steel, alloy steel, and other tough workpiece materials. An oxide and bronze straw coating reduces friction and improves chip evacuation during the cut. Overall length is 3.75 inches with a 2.5-inch flute length.

This jobber drill is intended for general-purpose metal drilling in machine shop, maintenance, and production environments. It follows a 12xD flute-to-diameter ratio and is built to ANSI and NAS 907 standards. Typical users include machinists, millwrights, pipefitters, and industrial maintenance technicians drilling mild steel, alloy steel, cast iron, aluminum, and similar materials on drill presses, lathes, and hand-held power drills. Primary workpiece material codes P, M, K, N, and S are supported per ISO tool designation.

Key Features

• Wire size No. 4 (0.2090 inch decimal equivalent) cobalt HSS construction for heat and wear resistance
• 135-degree standard split point with web thinning for fast self-centering starts
• Oxide and bronze straw coating reduces friction and aids chip flow
• Regular spiral flute with tapered web configuration for efficient chip evacuation
• Right-hand cutting direction; straight cylindrical shank fits standard chucks
• Built to ANSI and NAS 907 standards; Series R10CO-R15CO-R18CO

Compatibility

Designed as a general-purpose jobber-length drill bit for use in standard 3-jaw chucks and collet systems accepting a 0.2090-inch straight shank. Suitable for drilling steel, cast iron, aluminum, and comparable materials per primary workpiece material codes P, M, K, N, and S. Part of Series R10CO-R15CO-R18CO.

Installation Notes

Installation is performed by machinists or maintenance technicians using a drill press, lathe, or hand-held power drill with an appropriate chuck. Secure the straight shank fully in the chuck before operation and verify spindle runout is within acceptable tolerance. Always power down and de-energize the machine before bit changes. Use cutting fluid appropriate to the workpiece material to extend tool life and maintain dimensional accuracy.