Precision Twist Drill 5999060 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5999060 is a screw machine length drill bit designed for high-performance metal removal in demanding shop and field applications. Built from high speed steel with a coated finish, this bit features a 135-degree split point that reduces walking and requires no center punch on most surfaces. The web-thinned, tapered web design lowers thrust and improves chip evacuation. At 0.404 inches (Letter Size Y) in diameter with an overall length of 3-5/16 inches and a flute length of 1-15/16 inches, it fits standard drill chucks and drill presses used by machinists, maintenance mechanics, and fabrication professionals.

This bit is rated for heavy-duty use and carries a 2.5xD flute-to-diameter ratio optimized for screw machine operations where stub-length rigidity matters. Its right-hand spiral flute and straight-cylindrical shank make it compatible with standard drill press chucks and CNC turret setups. The primary target workpiece material is titanium, though the high speed steel construction and split point geometry also suit stainless steel, hardened alloys, and other difficult-to-machine metals encountered in production and maintenance environments. It meets ANSI and NAS 907 specifications, confirming dimensional and performance compliance for aerospace and industrial applications.

Key Features

• 135-degree split point reduces bit walking and lowers entry thrust
• Web-thinned tapered web improves chip flow and reduces heat buildup
• Screw machine (stub) length provides added rigidity over jobber-length bits in tight setups
• Coated high speed steel construction rated for titanium and difficult alloys
• Meets ANSI and NAS 907 specifications for dimensional accuracy
• Right-hand spiral flute with straight-cylindrical shank fits standard and CNC chucks

Compatibility

Designed as a screw machine length replacement or production drill bit for use in drill presses, turret lathes, and CNC screw machine setups requiring a 0.404-inch diameter hole. Fits any standard straight-shank drill chuck accepting up to at least 0.404 inches.

Installation Notes

Installation and use should be performed by a qualified machinist or maintenance mechanic familiar with proper cutting speeds and feeds for the target workpiece material. Secure the shank fully in the chuck before operation and verify chuck runout is within acceptable limits to protect the bit and workpiece. Use appropriate cutting fluid or coolant when drilling titanium or hardened alloys to extend tool life and manage heat. Inspect the cutting edges for wear or chipping before each use and replace the bit if the split point geometry is compromised.