Precision Twist Drill 5999439 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999439 is a screw machine length drill bit engineered for high-performance metal cutting in demanding shop and field environments. Built from high speed steel (HSS) with a coated finish, this bit features a 135-degree split point for fast self-centering starts and reduced thrust. The web-thinned, tapered web construction improves chip evacuation and cutting efficiency. At 0.4531 inches (29/64 inch) in diameter with a 3-9/16 inch overall length and a 2-1/8 inch flute length, it fits standard straight-cylindrical shank drill chucks. The right-hand spiral flute geometry delivers clean, controlled cuts in high-alloy and difficult-to-machine materials. Meets ANSI and NAS 907 specifications.

This drill bit is rated for primary use in titanium workpieces and other high-performance metal cutting applications. The screw machine length format — shorter than jobber length — provides added rigidity and reduced deflection, making it well suited for CNC machining centers, drill presses, and manual drilling operations where hole location accuracy matters. The R40C series is a heavy-duty grade intended for production environments where tool life and repeatability are priorities. Machinists, tool and die makers, and maintenance technicians working in aerospace, manufacturing, and general metalworking will find this bit appropriate for close-tolerance drilling work.

Key Features

• 135-degree split point for self-centering starts and reduced walking on hard materials
• Web-thinned tapered web improves chip flow and reduces cutting resistance
• High speed steel construction with coated finish for extended tool life
• Screw machine length provides greater rigidity and less deflection versus jobber-length bits
• Right-hand spiral flute, straight-cylindrical shank fits standard drill chucks
• Meets ANSI and NAS 907 specifications for dimensional and performance compliance

Compatibility

Designed for use in standard straight-shank drill chucks on CNC machining centers, drill presses, and hand-held drilling equipment. Primary workpiece material rating is titanium; suitable for general high-performance metalworking applications within the 0.4500 to 0.5000 inch drill bit size range.

Installation Notes

Installation and use should be performed by qualified machinists or maintenance technicians familiar with metal drilling operations. Secure the shank fully in the drill chuck and verify runout before use. Power down and de-energize all equipment before changing bits. Use appropriate cutting fluid or coolant as required by the workpiece material — note this bit does not feature through-coolant capability.