Precision Twist Drill 5997978 Jobber Drill Bit 39 Hss

Product Description

The PRECISION TWIST DRILL 5997978 is a jobber-length drill bit sized at wire gauge 39 (0.0995 inches decimal), manufactured from high speed steel with a bright uncoated finish. It features a standard 118-degree split-point angle, a regular spiral flute with web thinning, and a straight cylindrical shank. The overall length is 2.375 inches with a flute length of 1.375 inches. This bit is designed for general-purpose drilling operations and is installed by machinists, maintenance technicians, and trade professionals working in fabrication, HVAC, plumbing, and electrical applications where small-diameter precision holes are required.

This drill bit is suited for drilling into steel, cast iron, non-ferrous metals, superalloys, and titanium in both shop and field environments. The two-flute spiral design and web-thinned point promote efficient chip evacuation and reduce walking on entry. The straight cylindrical shank fits standard drill chucks across a wide range of handheld and bench-mount drilling equipment. It conforms to ANSI standards and carries a Series R10H-R18H designation, making it a direct fit for general-purpose production and maintenance drilling tasks.

Key Features

• Wire gauge 39 diameter — 0.0995 inches decimal equivalent
• 118-degree standard point angle with web-thinned tip for reduced thrust and cleaner entry
• High speed steel construction for durability across steel, cast iron, and non-ferrous workpiece materials
• Bright uncoated finish — compatible with cutting fluids and suitable for general-purpose use
• Regular right-hand spiral flute with tapered web configuration for consistent chip flow
• Straight cylindrical shank fits standard drill chucks without modification

Compatibility

Designed as a general-purpose jobber-length drill bit conforming to ANSI standards, Series R10H-R18H, for use in standard three-jaw drill chucks accepting a 0.0995-inch straight shank. Suitable for workpiece materials coded P (steel), K (cast iron), N (non-ferrous metals), and S (superalloys and titanium).

Installation Notes

This drill bit is installed by machinists and trade technicians using handheld drills, drill presses, or CNC drilling equipment. Secure the straight shank firmly in a keyed or keyless chuck before operation and verify chuck runout is within acceptable limits for small-diameter tooling. Apply appropriate cutting fluid when drilling ferrous materials to extend tool life and maintain hole quality. Do not exceed the recommended maximum drilling depth of 1.375 inches without retracting to clear chips.