Precision Twist Drill 5999105 Jobber Drill Bit Letter H 17/64

Product Description

The PRECISION TWIST DRILL 5999105 is a jobber-length drill bit sized to Letter H (17/64 inch, 0.2660 inch decimal) designed for general-purpose drilling in a wide range of materials. Built from high speed steel with a steam oxide coating, it runs a standard 118-degree point angle and a right-hand spiral flute for efficient chip evacuation. Overall length is 4.125 inches with a 2.875-inch flute length, giving it the reach needed for typical through-hole and blind-hole work. The straight-cylindrical shank at 0.2660 inch diameter fits standard three-jaw drill chucks. This is a Series R15 tool conforming to ANSI standards.

This bit is suited for drilling steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium in production and maintenance applications. It is a common choice for machinists, pipefitters, ironworkers, and general maintenance technicians who need a reliable letter-size bit for hand drilling or drill-press work. The 11xD flute-to-diameter ratio and tapered web with web thinning make it effective on tougher materials where a standard unmodified web would require excessive feed force.

Key Features

• Letter H size — 17/64 inch (0.2660 inch decimal) diameter for precise letter-series hole sizing
• High speed steel construction with steam oxide coating for lubricity and mild corrosion resistance
• 118-degree standard point angle for general-purpose use across a broad material range
• Right-hand spiral flute with tapered web and web thinning to reduce thrust on harder workpiece materials
• Straight-cylindrical shank compatible with standard drill chucks — no adapter required
• ANSI-conforming Series R15 jobber length — 4.125 inches OAL, 2.875-inch maximum drilling depth

Compatibility

Designed as a general-purpose jobber-length drill bit for use in standard three-jaw drill chucks accepting a 17/64 inch straight shank. Suitable for drill presses, hand drills, and machine-tool spindles configured for straight-shank tooling.

Installation Notes

Installation is performed by machinists, maintenance technicians, and trade professionals using standard drill chucks or collet holders rated for the shank diameter. Secure the shank fully in the chuck and confirm concentricity before cutting. Match spindle speed to workpiece material and bit diameter per standard cutting-speed tables — do not exceed recommended surface footage for high speed steel on hard alloys. Inspect the cutting edges and point geometry before each use; a damaged or improperly sharpened point will cause oversized holes and premature wear.