Precision Twist Drill 5997816 Cobalt Jobber Drill Bit

Product Description

The PRECISION TWIST DRILL 5997816 is a wire gauge size 71 cobalt jobber-length drill bit designed for drilling operations in ferrous and non-ferrous metals, stainless steel, and high-strength alloys. Ground to a 135-degree split point with web thinning, it starts on contact without a center punch and reduces walking on hard surfaces. The straight cylindrical shank measures 0.0260 inches in diameter and fits standard keyless or keyed drill chucks. A straw oxide finish provides mild lubricity and heat resistance during high-speed drilling. At 1.25 inches overall length with a 0.375-inch flute, this bit suits tight-clearance drilling in confined assemblies or thin stock.

This bit is suited for general-purpose production drilling in machine shops, maintenance environments, and light manufacturing. It performs in steel, cast iron, aluminum, plastics, and exotic alloys, covering workpiece material codes P, M, K, N, and S. The 14xD flute-to-diameter ratio and regular spiral flute geometry promote chip evacuation in short-depth holes. Typical applications include fixture drilling, sheet metal work, and precision hole placement where small-diameter accuracy matters. Licensed machinists, tool and die technicians, and maintenance mechanics are the primary installers.

Key Features

• Wire size 71 diameter: 0.0260 inches for precision small-bore drilling
• 135-degree standard split point with web thinning for self-centering entry
• Cobalt high-speed steel construction rated for heavy-duty cutting in hard materials
• Straw oxide coating adds lubricity and reduces heat buildup at the cutting edge
• Regular spiral, 2-flute geometry promotes clean chip evacuation in short-depth holes
• Meets ANSI and NAS 907 standards for dimensional and performance consistency

Compatibility

Part of the R10CO-R15CO-R18CO series. Designed as a general-purpose jobber drill compatible with standard straight-shank drill chucks accepting shanks at 0.0260 inches diameter.

Installation Notes

Installation is performed by machinists or maintenance technicians using a drill press, CNC machining center, or hand drill with a compatible chuck. Secure the shank fully in the chuck before operation and verify spindle speed matches recommended surface footage for the workpiece material. Do not use excessive feed pressure on small-diameter cobalt bits, as lateral stress can cause breakage. Cutting fluid or lubricant is recommended when drilling steel or stainless alloys to extend edge life.