Precision Twist Drill 5998392 No 78 Hss Jobber Drill Bit

Product Description

The PRECISION TWIST DRILL 5998392 is a wire gauge No. 78 jobber length drill bit ground from high speed steel (HSS) and finished with a bright uncoated surface. It measures 0.0160 inches (1/64 inch) in diameter with an overall length of 0.875 inches (7/8 inch) and a flute length of 0.1875 inches (3/16 inch). The 118-degree standard point and two-flute spiral design provide efficient chip evacuation during general-purpose drilling operations. This bit is sized for precision small-diameter work and is installed by machinists, tool-and-die techs, and maintenance technicians working with close-tolerance hole requirements.

The 5998392 is suited for drilling in steel, cast iron, non-ferrous metals, superalloys, and titanium. Its straight-cylindrical shank seats directly into standard drill chucks and collets without adapters, making it a practical choice for benchtop drill presses, CNC drilling operations, and handheld power tools wherever a No. 78 diameter hole is required. The regular spiral and tapered web configuration support consistent performance across moderate drilling depths up to 0.1875 inches (3/16 inch). General-purpose tool performance makes this an everyday production bit in light industrial and maintenance settings.

Key Features

• Wire gauge No. 78 diameter: 0.0160 inches (1/64 inch) for precise small-hole drilling
• 118-degree standard point angle for reliable starting and clean entry in common metals
• High speed steel construction provides hardness and heat resistance for general-purpose use
• Bright uncoated finish suitable for use with standard cutting fluids and oils
• Straight-cylindrical shank fits standard drill chucks and collets without adapters
• Web-thinned, tapered web construction reduces thrust and improves chip flow
• Meets ANSI specifications for jobber length drill bits

Compatibility

Designed as a general-purpose OEM-style jobber length drill bit in the R10H-R18H series, compatible with any standard drill chuck or collet sized to accept a 0.0160-inch straight-cylindrical shank.

Installation Notes

A licensed machinist or qualified technician should secure this bit in a properly sized drill chuck or collet before operation. Ensure the spindle is fully stopped and the machine is powered down before inserting or removing the bit. Use appropriate cutting fluid for the workpiece material to extend bit life and maintain hole quality. Do not exceed the maximum drilling depth of 0.1875 inches without retracting to clear chips.