Precision Twist Drill 5998829 3/8 in Taper Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5998829 is a taper length high speed steel drill bit designed for accurate, fast-penetration drilling in non-ferrous metals. Built to ANSI standards, it features a 118-degree standard point angle with web thinning on a tapered web configuration, which reduces walking and lowers thrust at entry. The bit runs a bright uncoated finish, right-hand spiral flute, and a 6xD flute-to-diameter ratio that clears chips efficiently in deeper passes. The cylindrical shank seats securely in standard three-jaw chucks. Machinists and fabricators working in production or maintenance environments will find this bit well-suited for consistent, repeatable hole quality in soft to medium materials.

This drill bit is sized at 3/8 inch (0.3750 inches) diameter with a 4.25-inch flute length and 6.75-inch overall length, placing it in the taper length category — longer than jobber length but shorter than aircraft extension bits. That extra reach is useful when drilling through thicker stock, structural members, or components where a jobber-length bit would fall short. Rated material applications include aluminum, aluminum alloy, copper, magnesium, and magnesium alloy. It is a general-purpose grade bit from the R51FS series, appropriate for both manual drill press work and CNC setups requiring non-coolant-through tooling.

Key Features

• 3/8 inch (0.3750 inches) diameter with matching 0.3750-inch cylindrical shank for a secure, chatter-free chuck fit
• 118-degree standard point angle with web thinning for reduced entry thrust and minimal walk
• High speed steel construction for durability across repeated use in non-ferrous materials
• 6xD flute-to-diameter ratio and fast spiral type promote efficient chip evacuation in deeper holes
• Bright uncoated finish — no coating buildup, easy to inspect for wear
• ANSI-compliant R51FS series, no coolant-through required

Compatibility

Rated for use in aluminum, aluminum alloy, copper, magnesium, and magnesium alloy. Fits any standard three-jaw drill chuck accepting a 0.3750-inch cylindrical shank. No compatibility with coolant-through tooling systems.

Installation Notes

Install in a drill press, lathe tailstock, or CNC spindle with a properly tightened three-jaw or keyed chuck before powering the machine. Secure the workpiece firmly — non-ferrous metals can grab and spin if not clamped. Run at appropriate surface speeds for the material being drilled; high speed steel bits are sensitive to excessive heat from improper feed rates. Inspect the cutting edges and web thinning before each use and remove from service if chipping or dulling is observed.