Precision Twist Drill 5998566 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998566 is a screw machine length drill bit designed for high-performance drilling in demanding trade and industrial applications. Built from high speed steel with a coated finish, this right-hand cut bit features a 135-degree split point and a web-thinned, tapered web configuration that reduces thrust and improves chip evacuation. At 0.221 inches in diameter with an overall length of 2-7/16 inches and a flute length of 1-5/16 inches, it falls within the R41C series and meets ANSI and NAS 907 standards. It is rated for heavy-duty service and is a strong choice for machinists and tool room technicians working with tight-tolerance holes.

This bit is engineered for primary use on titanium workpieces, where controlled cutting geometry and a rigid screw machine length body reduce deflection and walking. The shorter-than-jobber body is well suited to drill press work, CNC machining centers, screw machines, and turret lathe applications where rigidity and repeatability matter. The 2.5xD flute-to-diameter ratio supports efficient chip clearing in difficult-to-machine materials. Machinists, maintenance technicians, and tool crib professionals in manufacturing and fabrication environments are the primary users.

Key Features

• 135-degree split point reduces walking and lowers required entry force
• Web-thinned tapered web improves cutting efficiency in tough alloys including titanium
• High speed steel construction with coated finish for added wear resistance
• Screw machine length body provides extra rigidity compared to jobber-length bits
• Right-hand spiral flute promotes consistent chip evacuation
• Meets ANSI and NAS 907 standards for dimensional and performance conformance

Compatibility

Designed as an OEM-style screw machine length drill bit replacement suitable for standard straight-cylindrical shank drill chucks and collet holders used on drill presses, CNC machining centers, and turret lathes accepting a 0.221-inch diameter straight shank.

Installation Notes

Installation and use of this bit should be performed by qualified machinists or maintenance technicians familiar with rotating cutting tools. Secure the straight-cylindrical shank fully in a properly rated chuck or collet before operation and confirm runout is within acceptable tolerance. Power down and lock out the machine before changing bits or inspecting the cutting edge. Use appropriate cutting fluid or coolant when drilling titanium to manage heat and extend tool life.