Precision Twist Drill 5998520 Jobber Drill Bit 21/64 in Hss

Product Description

The PRECISION TWIST DRILL 5998520 is a jobber-length drill bit designed for general-purpose drilling in a wide range of materials. Built from high speed steel with a bright uncoated finish, this 21/64 inch diameter bit features a 118-degree standard point angle and a regular spiral flute geometry with web thinning for cleaner entry and reduced thrust. The straight-cylindrical shank seats securely in standard drill chucks. With an overall length of 4.625 inches and a flute length of 3.3125 inches, it delivers a maximum drilling depth of 3.3125 inches. Right-hand cut orientation and a two-flute configuration make it a straightforward fit for production and maintenance drilling tasks.

This bit is suited for drilling steel, cast iron, non-ferrous metals, superalloys, and titanium. It performs well in residential and light commercial maintenance, fabrication shops, and field service applications where a reliable general-purpose jobber-length drill bit is needed. The Series R10H-R18H designation covers a range of fractional sizes, and this 21/64 inch bit fits within the 0.3000 to 0.3500 inch decimal size range. It is sold individually and carries ANSI specification compliance.

Key Features

• 21/64 inch (0.3281 inch) diameter high speed steel construction for general-purpose durability
• 118-degree standard point angle with web-thinned, tapered web for reduced entry thrust
• Regular spiral, two-flute design for efficient chip evacuation
• Straight-cylindrical shank compatible with standard drill chucks
• Bright uncoated finish suitable for use with or without cutting fluid
• ANSI-compliant jobber-length geometry for consistent dimensional accuracy

Compatibility

Designed as a general-purpose jobber-length drill bit rated for steel, cast iron, non-ferrous metals, superalloys, and titanium. Compatible with any standard drill chuck accepting a 0.3281 inch straight-cylindrical shank.

Installation Notes

Installation is performed by machinists, maintenance technicians, and trade professionals using a standard drill press, hand drill, or CNC spindle. Secure the shank fully in the chuck before operation and confirm the workpiece is properly fixtured. Use appropriate cutting fluid when drilling steel or superalloys to extend tool life and manage heat. Inspect the cutting edges before each use and replace the bit if chipping or dulling is observed.