Precision Twist Drill 5998810 Jobber Drill Bit Letter I

Product Description

The PRECISION TWIST DRILL 5998810 is a jobber-length twist drill bit sized to Letter I (0.2720 inches), designed for general-purpose hole-making in metal fabrication, maintenance, and repair applications. Ground from high speed steel with a steam oxide coating, it runs a standard 118-degree split-point geometry with web thinning to reduce thrust on entry. The 2-flute spiral flute design with a tapered web clears chips efficiently during through-hole drilling. At 4.125 inches overall length with a 2.875-inch flute, this bit fits standard drill chucks and is sized to handle jobsite and shop drilling without extended reach tooling. Installation is performed by machinists, maintenance mechanics, and trade professionals working with ferrous and non-ferrous stock.

This drill bit is rated for use on steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. It covers the full range of general-purpose metal drilling tasks where a Letter I diameter hole is required. The straight cylindrical shank seats directly in standard drill chucks or collets on hand drills, drill presses, and CNC machining centers. The 11xD flute-to-diameter ratio and regular spiral type make it well suited for through-hole and blind-hole drilling at moderate feed and speed rates. It ships as a single bit and conforms to ANSI standards for jobber-length tooling.

Key Features

• Letter I size: 0.2720 inches diameter with matching straight cylindrical shank
• 118-degree standard point angle with web thinning for reduced entry thrust
• Steam oxide coating improves lubricity and light corrosion resistance during storage
• 2-flute spiral configuration with tapered web for efficient chip evacuation
• Maximum drilling depth of 2.875 inches matches full flute length
• ANSI-compliant jobber-length geometry fits standard drill chucks without adapters

Compatibility

Designed as an OEM-style jobber-length drill bit conforming to ANSI standards, compatible with any standard drill chuck or collet accepting a 0.2720-inch straight cylindrical shank. Suitable for use in hand drills, drill presses, and CNC machining centers. Rated for steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium workpieces.

Installation Notes

Install and remove drill bits only with the drill unplugged or the machine in a locked-out, de-energized state per applicable lockout/tagout procedures. Secure the shank fully in the chuck and tighten with a chuck key before operation. Use appropriate cutting fluid or coolant for the workpiece material to extend tool life, especially on stainless steel and superalloys. Inspect the cutting edges for chipping or wear before each use and replace worn bits to maintain hole-size accuracy and prevent workpiece damage.