Precision Twist Drill 5997711 Cobalt Jobber Drill No 20

Product Description

The PRECISION TWIST DRILL 5997711 is a cobalt jobber-length drill bit sized to No. 20 wire gauge (0.1610 inches diameter). Built from cobalt high-speed steel with an oxide and bronze straw finish, it is designed for heavy-duty drilling in steel and other demanding materials. The 135-degree split point self-centers on contact, reducing the need for a center punch and minimizing walking on hard surfaces. With an overall length of 3.25 inches and a flute length of 2.125 inches, it fits standard drill chucks and is suited for production and maintenance drilling applications where tool life and hole quality matter.

This bit is intended for drilling steel, cast iron, non-ferrous metals, and similar materials in industrial, machining, and fabrication environments. The right-hand cutting direction and regular spiral flute geometry handle general-purpose through-hole drilling efficiently. It conforms to ANSI and NAS 907 standards, making it a direct fit for applications that specify NAS-compliant tooling. Machinists, tool and die makers, maintenance technicians, and metalworking professionals are the primary users of this bit.

Key Features

• Cobalt high-speed steel construction for extended tool life in steel and hard alloys
• 135-degree split point self-centers and reduces thrust force compared to standard 118-degree points
• Oxide and bronze straw coating improves lubricity and heat resistance
• Web-thinned tapered web reduces torque and improves chip evacuation
• Right-hand cut with regular spiral flutes for consistent chip clearing
• Straight cylindrical shank fits standard drill chucks without adapters
• Meets ANSI and NAS 907 standards

Compatibility

Part of the R10CO-R15CO-R18CO series. Designed as an OEM-style replacement or direct-use cobalt jobber drill for applications specifying a No. 20 wire-size (0.1610 inch) hole in steel and similar workpiece materials coded P, M, K, N, and S.

Installation Notes

Installation is performed by machinists or qualified technicians using a standard drill press, CNC machine, or handheld power drill with a chuck rated for the shank diameter. Secure the workpiece firmly before drilling and apply cutting fluid when drilling steel to extend bit life and improve finish. Do not exceed the recommended drilling depth of 2.125 inches per pass without retracting to clear chips. Inspect the cutting edges before use and replace the bit if the point shows signs of wear or chipping.