Precision Twist Drill 5999362 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999362 is a screw machine length drill bit engineered for high-performance drilling in demanding trade and industrial applications. Measuring 0.257 inches (Letter F) in diameter with an overall length of 2-5/8 inches and a flute length of 1-7/16 inches, this bit is built from high speed steel with a coated finish for extended tool life. The 135-degree split point starts on contact without a center punch and reduces walking, while the web-thinned, tapered web design lowers thrust requirements during penetration. The R42C series is rated heavy duty and carries ANSI and NAS 907 designations.

This drill bit is designed for screw machine length applications where a shorter, more rigid tool body improves accuracy and reduces deflection. The primary rated workpiece material is titanium, making this bit appropriate for aerospace, defense, and specialty fabrication work where conventional bits lose edge quickly. The regular spiral flute with a 2.5xD flute-to-diameter ratio provides consistent chip evacuation. Machinists, tool-and-die professionals, and precision fabricators working with hard or abrasive metals are the primary end users for this series.

Key Features

• 0.257 inch (Letter F) diameter with screw machine length for maximum rigidity
• 135-degree split point with web thinning for no-walk starting and reduced thrust
• High speed steel construction with coated finish for extended cutting life
• Right hand cut, regular spiral flute for consistent chip removal
• Heavy duty grade meeting ANSI and NAS 907 specifications
• Straight-cylindrical shank fits standard drill chucks without adapters

Compatibility

Designed as a heavy-duty OEM-style replacement or tooling addition for screw machine and precision drilling setups requiring a 0.257 inch diameter bit in the 0.2500 to 0.3000 inch size range per ANSI and NAS 907 standards.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or trade professionals familiar with drill press, CNC, or hand-held drilling equipment. Secure the straight-cylindrical shank fully in the chuck before operation and verify chuck key removal prior to startup. When drilling titanium or similarly hard materials, use appropriate cutting fluid and controlled feed rates to prevent work hardening and premature edge wear. Coolant-through is not supported on this bit, so external lubrication is required for optimal performance in hard-metal applications.