Precision Twist Drill 5998233 Jobber Drill Bit No. 21

Product Description

The PRECISION TWIST DRILL 5998233 is a jobber-length twist drill bit in wire gauge size No. 21 (0.1590 inches decimal), manufactured from high speed steel with a bright, uncoated finish. It features a standard 118-degree split point and a regular spiral flute designed for right-hand cutting. The overall length is 3.25 inches, with a 2.125-inch flute length and a straight-cylindrical shank of 0.1590 inches in diameter. This is a general-purpose drilling tool suited for use by machinists, maintenance technicians, metalworkers, and trade professionals who need reliable performance in everyday drilling operations.

This drill bit is built for drilling steel, cast iron, non-ferrous metals, superalloys, and titanium. It is commonly used in production and maintenance settings where wire-gauge drill sizes are required for tapping, reaming preparation, or precision hole sizing. The 13xD flute-to-diameter ratio and tapered web configuration with web thinning support efficient chip evacuation and reduced thrust in moderate-depth applications. The straight-cylindrical shank fits standard drill chucks without modification.

Key Features

• Wire gauge size No. 21 — 0.1590 inches decimal diameter
• 118-degree standard point angle with web-thinned, tapered web for reduced thrust
• High speed steel construction for durability across a range of workpiece materials
• Bright, uncoated finish suitable for general-purpose use
• Regular right-hand spiral flute with 2.125-inch maximum drilling depth
• Meets ANSI standards; Series R10H-R18H

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with standard drill chucks accepting a 0.1590-inch straight-cylindrical shank. Suitable for use on steel, cast iron, non-ferrous metals, superalloys, and titanium workpieces.

Installation Notes

Install in a compatible drill chuck and tighten securely before operation. Power down or de-energize all equipment before changing bits. Use appropriate cutting fluid or lubrication when drilling steel or harder alloys to extend tool life. Inspect the cutting edges for wear or chipping before each use and replace if the point is damaged.