Precision Twist Drill 5999052 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999052 is a screw machine length drill bit designed for high-performance metal cutting in demanding trade and industrial applications. Built from high speed steel with a coated finish, this bit features a 0.386 inch (Letter W) diameter, a 135-degree split point, and web thinning for reduced thrust and faster penetration. The straight-cylindrical shank seats securely in standard drill chucks. At 3.25 inches overall length with a 1.875 inch flute length, it is sized for short-hole work in tight setups such as machine tools, drill presses, and CNC spindles. Licensed machinists and maintenance techs specify this series for its heavy duty grade and compliance with ANSI and NAS 907 standards.

This bit is rated for primary use in titanium workpieces, making it well suited for aerospace MRO, industrial fabrication, and precision machining environments where tool life and hole quality are critical. The R42C series combines a regular spiral flute, tapered web configuration, and a 2.5xD flute-to-diameter ratio to balance chip evacuation and rigidity. No coolant-through capability is present, so flood or mist cooling applied externally is standard practice when drilling titanium.

Key Features

• 0.386 inch diameter, Letter W sizing per ANSI standards
• 135-degree split point with web thinning reduces walking and lowers thrust requirements
• High speed steel construction with coated finish extends tool life in hard materials
• Screw machine length (3.25 inches overall) provides maximum rigidity for short-hole drilling
• Right hand cut, regular spiral flute for efficient chip removal
• Meets ANSI and NAS 907 specifications for heavy duty, high performance applications

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit for standard straight-shank drill chucks and collet holders accepting a 0.386 inch shank diameter.

Installation Notes

Installation is performed by machinists and maintenance technicians using drill presses, milling machines, or CNC machining centers. Always power down and lock out the spindle before changing tooling. Secure the straight-cylindrical shank fully into the chuck or collet to the recommended engagement depth before tightening. When drilling titanium, apply external flood or mist cooling and use appropriate feeds and speeds to prevent work hardening and premature tool wear.