Precision Twist Drill 5998243 Cobalt Jobber Drill 13/64

Product Description

The PRECISION TWIST DRILL 5998243 is a cobalt jobber-length drill bit ground to a 135-degree split point for reduced walking and easier penetration in hard materials. Measuring 13/64 inch (0.2031 inch) in diameter with an overall length of 3-5/8 inches, this bit carries a straw oxide finish that provides mild lubricity and heat resistance during drilling operations. The web-thinned, tapered-web construction reduces thrust requirements at entry. Built to ANSI and NAS 907 standards, it is suited for heavy-duty general-purpose drilling in ferrous and non-ferrous metals. Machinists, maintenance technicians, and metal fabricators working in demanding shop or field environments will find this bit appropriate for production and repair drilling tasks.

This cobalt jobber drill is intended for drilling steel, stainless steel, cast iron, aluminum, and other materials covered by workpiece material codes P, M, K, N, and S. The straight cylindrical shank fits standard drill chucks without adapters. With a 12xD flute-to-diameter ratio and a maximum drilling depth of 2-7/16 inches, this bit handles through-holes and deep spot applications in both manual and machine setups. It belongs to the R10CO-R15CO-R18CO series and is sold individually.

Key Features

• Cobalt construction for improved heat resistance and hardness retention when drilling tough alloys
• 135-degree split point reduces walking and minimizes required drilling thrust
• Straw oxide finish provides mild lubricity and corrosion resistance during use
• Web-thinned, tapered-web design lowers entry force and chip load
• Right-hand, regular spiral flute promotes efficient chip evacuation
• Meets ANSI and NAS 907 standards for heavy-duty drill bit performance

Compatibility

Designed for use in standard drill chucks accepting a 13/64 inch straight cylindrical shank. Suitable for drilling workpiece material codes P, M, K, N, and S, including carbon steel, alloy steel, cast iron, aluminum, and non-ferrous metals. Part of the PRECISION TWIST DRILL R10CO-R15CO-R18CO series.

Installation Notes

Install and operate this drill bit with the machine powered down and the chuck fully secured before starting the spindle. Use appropriate cutting fluid or coolant for the workpiece material to extend tool life; this bit does not support through-coolant delivery. Machinists should verify chuck capacity and spindle speed settings against the workpiece material and bit diameter before drilling. Wear proper eye protection and secure the workpiece with appropriate fixturing before operation.