Precision Twist Drill 5995478 Jobber Drill Bit 25/64 Hss

Product Description

The PRECISION TWIST DRILL 5995478 is a jobber-length drill bit designed for general-purpose drilling in steel, cast iron, and similar ferrous and non-ferrous materials. It measures 25/64 inch (0.3906 inches) in diameter with a 118-degree standard point angle and a bright, uncoated HSS finish. The left-hand cutting direction makes it well-suited for extraction applications where reverse-rotation drilling is required, such as removing broken fasteners. A web-thinned, tapered web configuration reduces thrust at the point and improves chip flow. Licensed machinists, millwrights, and maintenance technicians are the primary users of this bit.

This bit fits standard jobber-length applications in metal fabrication shops, maintenance and repair operations, and industrial production environments. It performs in drilling through steel and cast iron workpieces, with a maximum drilling depth of 3.75 inches. The straight shank seats directly into standard drill chucks without an adapter. The Series L10 designation places this bit in a general-purpose jobber category conforming to ANSI standards, making it a reliable stock item for trade and industrial tool cribs.

Key Features

• Left-hand cut direction for reverse-rotation drilling and broken fastener extraction
• 118-degree standard point angle with web-thinned, tapered web for reduced thrust
• HSS construction with bright uncoated finish for general-purpose ferrous drilling
• Regular spiral flute with 2 flutes and 3.75-inch flute length for efficient chip evacuation
• Straight shank at 0.3906 inches diameter fits standard drill chucks directly
• ANSI-compliant Series L10 jobber-length specification

Compatibility

Designed as a general-purpose jobber-length replacement or stock drill bit for use in any standard drill chuck accepting a 25/64-inch straight shank. Primary workpiece materials include steel and cast iron. Material codes P, M, K, N, and S apply per the input specification.

Installation Notes

Installation is performed by machinists, maintenance technicians, or millwrights using a standard keyed or keyless drill chuck. Ensure the drill press or handheld drill is powered down and the chuck is fully secured before beginning drilling operations. Left-hand bits require a reverse-rotation drill or driver to function as intended. Follow applicable ANSI and shop safety protocols for workpiece clamping and eye protection when drilling ferrous metals.