Precision Twist Drill 5999138 Jobber Drill Bit No. 60

Product Description

The PRECISION TWIST DRILL 5999138 is a jobber-length drill bit sized to wire gauge No. 60 (0.0400 inches diameter) for precision small-diameter drilling in metal and hard materials. The bit is ground from high speed steel (HSS) and finished with a steam oxide coating to reduce friction and resist corrosion during dry cutting. The 118-degree standard point angle suits general-purpose entry into steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. Overall length is 1.625 inches with an 11/16-inch (0.6875 inches) spiral flute and a 15/16-inch straight-cylindrical shank. Right-hand cutting direction and a regular spiral type make it compatible with standard drill chucks and CNC spindles alike.

This bit is intended for production and maintenance drilling in applications where tight hole tolerances and small diameters are required. Typical use cases include drilling pilot holes, clearance holes, and precision holes in ferrous and non-ferrous metals across light manufacturing, tool-and-die, and general machine shop work. The web-thinned, tapered web design reduces thrust during entry, which is especially useful in harder workpiece materials such as stainless steel and superalloys. Series R18 designation identifies this as part of the PRECISION TWIST DRILL R10-R15-R18 family of jobber-length HSS bits built to ANSI standards.

Key Features

• Wire gauge No. 60 size — 0.0400 inches diameter for small-diameter precision drilling
• High speed steel construction with steam oxide finish for reduced friction
• 118-degree standard point angle suitable for a wide range of metals and hard materials
• Web-thinned, tapered web reduces drilling thrust in hard or tough materials
• 2-flute spiral design with 11/16-inch flute length and 17xD flute-to-diameter ratio
• Straight-cylindrical shank fits standard chucks; right-hand cut for conventional drilling

Compatibility

Designed as a general-purpose OEM-style replacement or stock bit for use in applications requiring wire gauge No. 60 diameter holes in steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. Conforms to ANSI standards and fits within the PRECISION TWIST DRILL R10-R15-R18 series family.

Installation Notes

Installation and use should be performed by qualified machinists or technicians familiar with small-diameter drilling practices. Secure the straight-cylindrical shank in a properly sized collet or drill chuck before operation, and verify chuck runout is within tolerance — excessive runout accelerates wear and breakage on small-diameter bits. Power down the machine completely before changing bits. Do not force-feed the bit; light, consistent feed pressure is critical at this diameter to prevent breakage.