Precision Twist Drill 5999402 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999402 is a screw machine length drill bit engineered for high-performance metal cutting applications. Built from high speed steel with a coated finish, this bit features a 135-degree split point and web-thinned, tapered web geometry that reduces walking on entry and lowers thrust force at the cut. The straight-cylindrical shank seats securely in standard drill chucks and screw machine spindles. At 0.316 inches in diameter and 2-15/16 inches overall length, it is well suited for close-tolerance drilling in confined setups where a jobber-length bit would be too long. Meets ANSI and NAS 907 specifications.

This bit is classified as heavy duty and is rated for primary use in titanium and similarly demanding workpiece materials. The screw machine length body, combined with a 2.5xD flute-to-diameter ratio and spiral flute design, promotes efficient chip evacuation in short, deep cuts. It is appropriate for use on manual drill presses, CNC screw machines, and turret lathes in production and job-shop environments. Machinists, tool-and-die workers, and aerospace maintenance technicians are the primary users of this series.

Key Features

• 135-degree split point reduces drill walking and entry thrust
• Web-thinned tapered web improves cutting efficiency in hard materials
• High speed steel construction with coated finish for extended tool life
• Screw machine length body for use in tight clearance setups
• Right-hand spiral flute promotes positive chip evacuation
• Meets ANSI and NAS 907 standards for dimensional and performance compliance

Compatibility

Designed as a direct-fit replacement or production-run bit for applications requiring a 0.316-inch (Letter O) diameter screw machine length drill in standard straight-cylindrical shank toolholders and screw machine spindles.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or maintenance technicians familiar with metal cutting operations. Ensure the spindle is fully stopped and the machine is de-energized before inserting or removing the bit from the chuck or collet. Secure the straight-cylindrical shank fully within the chuck jaws to the recommended grip depth to prevent slippage under load. Coolant-through is not supported on this bit, so apply cutting fluid externally when drilling titanium or other high-hardness materials to manage heat buildup.