Precision Twist Drill 5998968 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998968 is a screw machine length drill bit designed for high-performance drilling in metalworking and fabrication applications. Manufactured from high speed steel with a bright, uncoated finish, this bit features a 0.386-inch (letter size W) diameter and a standard 118-degree point angle. The right-hand spiral flute geometry and web-thinned, tapered web construction reduce cutting resistance and improve chip evacuation. At 3.25 inches overall length with a 1.875-inch flute length, this compact stub-length bit provides added rigidity over jobber-length alternatives, making it well suited for precision hole placement in close-quarters setups.

This drill bit is built for use in screw machine operations, CNC drilling, and manual drill press work where stub-length rigidity and accurate starting are priorities. The R42 series is rated for general purpose use with a high-performance classification under ANSI standards. Primary workpiece material is listed as titanium, though the high speed steel construction and general purpose grade make this bit applicable across a range of metals and alloys. The straight-cylindrical shank fits standard three-jaw drill chucks without the need for adapters.

Key Features

• Screw machine (stub) length for increased rigidity and reduced deflection
• High speed steel construction with bright, uncoated finish
• 118-degree standard point angle with web-thinned, tapered web for reduced entry force
• Right-hand cut with regular spiral flute for efficient chip removal
• 2.5xD flute-to-diameter ratio for controlled chip flow
• Straight-cylindrical shank for universal chuck compatibility
• ANSI-compliant, Series R42

Compatibility

Designed as an OEM-style replacement and standard fitment for screw machine drill bit applications requiring a 0.386-inch (letter W) diameter, straight-cylindrical shank bit in the 0.3500 to 0.4000 inch diameter range per ANSI specification.

Installation Notes

Installation is performed by machinists, tool and die technicians, and general fabricators using a compatible drill press, CNC machine, or hand drill with a three-jaw chuck. Secure the shank fully in the chuck before operation and verify chuck key is removed prior to powering the machine. Inspect the cutting edges for wear or chipping before each use. Follow applicable shop safety protocols and machine manufacturer guidelines for speed and feed settings.