Precision Twist Drill 5998840 Drill Bit Letter B Hss

Product Description

The PRECISION TWIST DRILL 5998840 is a jobber-length drill bit sized to Letter B (0.2380 inches) and manufactured from high-speed steel with a bright, uncoated finish. It features a 118-degree standard point angle, a two-flute regular spiral design, and a web-thinned, tapered web configuration for improved chip evacuation and reduced thrust when starting a hole. The overall length is 4 inches with a 2.75-inch flute length, giving it a 12xD flute-to-diameter ratio. The straight-cylindrical shank diameter matches the bit diameter at 0.2380 inches. This is a general-purpose drilling tool suited for machinists, maintenance technicians, and fabricators working on production or repair applications.

The 5998840 is designed for drilling into a wide range of workpiece materials including steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. It fits the Series R10P, R15P, and R18P line from PRECISION TWIST DRILL. The right-hand cutting direction and standard point geometry make it compatible with conventional drill presses, hand drills, and CNC machining centers that accept straight-shank tooling. Typical applications include through-hole and blind-hole drilling in general manufacturing, structural fabrication, and MRO settings.

Key Features

• Letter B size — 0.2380 inches decimal equivalent
• 118-degree standard point angle with web-thinned, tapered web for reduced entry thrust
• High-speed steel construction — bright, uncoated finish for general-purpose use
• Two-flute regular spiral geometry supports efficient chip removal
• Maximum drilling depth of 2.75 inches matches full flute length
• Straight-cylindrical shank with zero flats for broad chuck compatibility
• Conforms to ANSI standards

Compatibility

Part of the PRECISION TWIST DRILL Series R10P, R15P, and R18P product family. Designed as a general-purpose OEM-style jobber drill for use in standard three-jaw drill chucks and collet systems accepting 0.2380-inch straight shanks.

Installation Notes

Installation is performed by machinists or maintenance technicians using a standard drill press, hand drill, or CNC spindle. Secure the shank fully in the chuck before operation and verify chuck key is removed before starting the machine. Always wear appropriate eye protection and secure the workpiece to prevent rotation. Follow applicable ANSI B94 tooling standards and shop safety procedures when setting feed rates and speeds for the workpiece material.