Precision Twist Drill 5998661 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5998661 is a screw machine length drill bit designed for high-performance drilling in tight-tolerance applications. Built from high speed steel with a coated finish, it measures 0.042 inches in diameter and features a 135-degree split point with web thinning for fast, accurate starts with minimal walking. At 1-3/8 inches overall length and a 1/2-inch flute length, this bit is engineered for stub-length drilling where clearance is limited. It carries a right-hand spiral flute with a straight-cylindrical shank and conforms to ANSI and NAS 907 specifications. Licensed HVAC techs, machinists, and trade professionals working in confined spaces rely on this format for precision work.

This drill bit is rated for primary use on titanium workpieces and is classified as heavy duty with a flute-to-diameter ratio of 2.5xD, making it suitable for demanding production and maintenance drilling tasks. The R41C series screw machine format is a standard stub-length configuration used across industrial, mechanical, and field service environments where a full-length jobber bit would be impractical. Its compact profile is well suited to drill press, hand drill, or CNC chuck applications where rigidity and runout control matter.

Key Features

• 0.042 inch diameter, wire gauge size 58, for fine-tolerance holes
• 135-degree split point with web thinning reduces thrust and minimizes drill walking
• High speed steel construction with coated finish for extended tool life
• Screw machine length at 1-3/8 inches overall for use in confined or short-clearance setups
• Right-hand cut, regular spiral flute with tapered web configuration
• Meets ANSI and NAS 907 standards for dimensional and performance compliance

Compatibility

Designed as an OEM-style replacement and standard production drill bit for use in screw machine, drill press, hand drill, and CNC chuck setups requiring a stub-length bit in the 0.042 inch diameter range.

Installation Notes

This bit is intended for use by machinists, maintenance technicians, and trade professionals familiar with small-diameter tooling. Secure the straight-cylindrical shank fully in the chuck before operation and verify runout before drilling. Use appropriate cutting fluid or coolant when drilling titanium or other hard materials to prevent premature wear. Do not exceed the rated speed range for the bit diameter and workpiece material combination.