Precision Twist Drill 5998139 Cobalt Jobber Drill 1/32 in

Product Description

The PRECISION TWIST DRILL 5998139 is a cobalt jobber-length drill bit designed for drilling steel and other demanding workpiece materials. It measures 1/32 inch (0.0312 inch) in diameter with a 1-3/8 inch overall length and a 1/2 inch flute length. The 135-degree split point reduces walking on entry and lowers the thrust required to start the hole. A straw oxide finish provides moderate heat and corrosion resistance. Web thinning and a tapered web configuration further reduce cutting resistance. This bit is built to heavy-duty standards and suits production and maintenance drilling environments where tool life and hole quality matter. Licensed technicians and machinists are the primary users.

This drill bit is suited for drilling steel, cast iron, non-ferrous metals, and similar materials in both shop and field applications. It fits standard 3-jaw chucks on hand drills, drill presses, and CNC machining centers that accept straight-shank tooling. The 16xD flute-to-diameter ratio makes it a true jobber-length format, appropriate for through-holes and moderate-depth blind holes in a wide range of materials including carbon steel, alloy steel, and stainless steel.

Key Features

• Cobalt high-speed steel construction for improved heat resistance and tool life in ferrous materials
• 135-degree split point reduces drill walking and decreases required entry thrust
• Straw oxide finish adds corrosion resistance and reduces friction during cutting
• Web-thinned, tapered web configuration lowers cutting resistance at the center
• Right-hand, regular spiral flute geometry promotes consistent chip evacuation
• Straight-cylindrical shank fits standard 3-jaw chucks without adapters
• Meets ANSI and NAS 907 standards for dimensional accuracy and material specification

Compatibility

Part of the R10CO-R15CO-R18CO series. Designed as a general-purpose cobalt jobber drill for use in straight-shank drill chucks across hand drills, drill presses, and CNC machining centers. Intended workpiece materials include steel, cast iron, and non-ferrous metals as indicated by primary workpiece material codes P, M, K, N, and S.

Installation Notes

Install in a properly sized drill chuck and tighten securely before use. Ensure the workpiece is clamped or fixtured to prevent movement during drilling. Use appropriate cutting fluid or coolant for ferrous workpiece materials to extend tool life. Inspect the cutting edge for wear or chipping before each use and replace the bit if the point shows signs of degradation.