Precision Twist Drill 5998490 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998490 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 bright, uncoated finish, this bit measures 35/64 inch (0.5469 inches) in diameter and carries a 118-degree standard point angle for reliable, centered entry on a wide range of materials. The straight-cylindrical shank and web-thinned, tapered web construction reduce cutting resistance and improve chip evacuation. It is intended for installation by machinists, maintenance technicians, and skilled tradespeople working with drill presses, lathes, or hand-held equipment requiring stubby, rigid tooling.

This Series R40 bit is rated for high-performance cutting and is listed with a primary workpiece material of titanium, making it appropriate for aerospace, industrial maintenance, and general-purpose fabrication environments where harder materials are encountered. The screw machine length format provides a shorter overall profile than jobber-length bits, increasing rigidity and reducing deflection in short-hole drilling operations. It conforms to ANSI standards and is suited for shops and field technicians who require consistent, repeatable results in production or repair settings.

Key Features

• 35/64 inch (0.5469 inches) diameter with a 118-degree standard point angle for accurate entry
• High speed steel construction for durability across general-purpose and high-performance applications
• Web-thinned, tapered web design reduces thrust load and improves chip flow
• Screw machine length provides increased rigidity and reduced deflection compared to jobber-length bits
• Spiral flute with 2.5xD flute-to-diameter ratio supports efficient chip evacuation
• Conforms to ANSI standards; right-hand cut with straight-cylindrical shank for broad machine compatibility

Compatibility

Designed as a screw machine length replacement or production drill bit for use in standard drill chucks accepting a straight-cylindrical shank in the 0.5000 to 0.6000 inch diameter range, conforming to ANSI specifications.

Installation Notes

Secure the shank fully in a drill chuck rated for the diameter before operation and verify chuck key is removed before powering the machine. Power down and de-energize all equipment before changing bits. Use appropriate cutting fluid or coolant for the workpiece material to extend tool life, noting that this bit does not support coolant-through delivery. Always wear appropriate eye protection and follow applicable OSHA and facility safety standards when operating drilling equipment.