Precision Twist Drill 5998941 Screw Machine Drill Bit R

Product Description

The PRECISION TWIST DRILL 5998941 is a screw machine length drill bit designed for high-performance drilling in demanding shop and production environments. Sized at letter R (0.3390 inches), it is manufactured from high speed steel with a coated finish for extended tool life. The 135-degree split point reduces walking on entry and lowers thrust requirements, making it well suited for drilling titanium and other hard or work-hardening materials. At 3 inches overall length with a 1-11/16-inch flute length, this stub-length geometry provides added rigidity compared to jobber-length bits. It follows a 2.5xD flute-to-diameter ratio and features a web-thinned, tapered web configuration for improved chip evacuation.

This drill bit is intended for use in screw machines, CNC machining centers, drill presses, and manual production setups where a short, rigid tool is preferred. The primary workpiece material rating is titanium, but the heavy-duty grade and high-performance classification make it appropriate for other tough alloys and hard metals as well. It is typically installed and used by machinists, tool-and-die workers, and production drilling technicians in light manufacturing and metalworking facilities. The straight-cylindrical shank fits standard drill chucks and collet holders without modification.

Key Features

• Letter R size (0.3390 inches) for precise production drilling
• 135-degree split point reduces entry thrust and eliminates center-punching on hard materials
• High speed steel construction with coated finish for improved wear resistance
• Screw machine (stub) length provides extra rigidity and minimizes deflection
• Web-thinned tapered web improves chip evacuation in deep or interrupted cuts
• Right-hand spiral flute, regular spiral type for standard cutting direction
• Meets ANSI and NAS 907 standards for dimensional and performance compliance

Compatibility

Designed as an OEM-style replacement or direct-use screw machine drill bit in standard drill chucks and collet systems accepting a straight-cylindrical shank; rated for titanium and hard metal drilling applications per Series R42C specifications.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with high-speed steel tooling and production drilling practices. Secure the straight-cylindrical shank fully in the chuck or collet before operation, and verify that the spindle speed and feed rate are appropriate for the workpiece material and bit diameter. Do not exceed the rated duty of the tool by forcing the bit through hardened material beyond its design capacity. Inspect the cutting edges for wear or chipping before each use, as damaged split-point geometry can cause workpiece damage or tool breakage.