Precision Twist Drill 5999766 Taper Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5999766 is a taper length drill bit designed for general-purpose metal drilling across a wide range of materials. Built from high speed steel with a bright/uncoated finish, this bit measures 0.3750 inches (3/8 inch) in diameter with a 118-degree standard point angle. The overall length is 6.75 inches and the flute length is 4.25 inches, providing extended reach compared to a jobber-length bit. A right-hand spiral flute with web thinning improves chip evacuation and reduces thrust at the point. The straight shank fits standard drill chucks without adapters. This is a Series R51 bit conforming to ANSI standards.

This bit is suited for drilling in alloy steel, carbon steel, stainless steel, cast iron, malleable iron, aluminum, aluminum alloy, brass, bronze, high strength bronze, copper, magnesium, magnesium alloy, nickel, nickel alloy, reinforced plastic materials, cermet, and graphite. The taper length profile is commonly used in production machining and maintenance environments where extra reach is needed to clear deep holes or thick stock. It installs in any standard drill press, milling machine, or hand drill with a chuck sized for a 0.3750-inch straight shank.

Key Features

• High speed steel construction for durability across ferrous and non-ferrous materials
• 118-degree standard point angle with web thinning to reduce walking and cutting resistance
• Taper length body at 6.75 inches overall with a 4.25-inch flute length for extended reach
• Right-hand spiral flute promotes efficient chip removal during drilling
• Bright/uncoated finish — no coating to flake or separate during high-speed runs
• Tapered web configuration and 6xD flute-to-diameter ratio support deeper hole drilling
• ANSI-standard geometry; Series R51 general-purpose grade

Compatibility

Designed as a general-purpose taper length drill bit compatible with any standard drill chuck accepting a 0.3750-inch straight shank, including drill presses, lathes, and hand-held power drills used in fabrication, HVAC, plumbing, and electrical trade work.

Installation Notes

Secure the straight shank fully in a properly sized drill chuck before operation and verify chuck key is removed before starting the spindle. Use appropriate cutting fluid or lubricant when drilling stainless steel, nickel alloys, or hardened steel to extend tool life and prevent work hardening. Ensure the workpiece is clamped securely to prevent rotation. Inspect the cutting edges for wear or chipping before each use and replace the bit if the point geometry is degraded.