Precision Twist Drill 5998029 Taper Length Drill Bit 28

Product Description

The PRECISION TWIST DRILL 5998029 is a taper length drill bit from the QC91P series, designed for heavy-duty drilling in a wide range of metals and alloys. Built from high-speed steel (HSS) with a bright/uncoated finish, it features a 135-degree split point that reduces walking and requires no center punch on most surfaces. The parabolic flute geometry improves chip evacuation and allows faster feed rates compared to standard flute profiles. The web-thinned, tapered web configuration reduces thrust and extends tool life. At 5.375 inches overall length with a 3-inch flute, this bit handles deeper reach applications that standard jobber-length drills cannot.

This bit is sized to wire gauge 28 (0.1405 inches decimal equivalent) and is suited for precision hole work in production and maintenance environments. The straight cylindrical shank fits standard drill chucks without adapters. Its taper length body makes it a practical choice for machinists, toolroom technicians, and maintenance mechanics drilling through alloy steel, stainless steel, cast iron, aluminum, brass, bronze, copper, titanium, and similar materials where a jobber-length bit lacks reach or rigidity.

Key Features

• Wire size 28 (0.1405 inches decimal equivalent) for precision-diameter holes
• 135-degree split point reduces drill walk and cutting pressure at entry
• Parabolic flute design promotes rapid chip evacuation at higher feed rates
• Web-thinned tapered web lowers thrust and extends cutting edge life
• Taper length body extends reach beyond standard jobber-length drills
• High-speed steel construction rated for heavy-duty general-purpose metalworking

Compatibility

Designed as a direct-fit replacement or addition for any setup using a standard straight-shank drill chuck; compatible across alloy steel, aluminum, aluminum alloy, brass, bronze, carbon steel, cast iron, copper, graphite, hardened steel, magnesium, magnesium alloy, malleable iron, nickel, stainless steel, steel, tempered steel, titanium, and titanium alloy workpieces as specified by the manufacturer.

Installation Notes

Install into a properly sized drill chuck rated for straight-shank tooling and tighten securely with a chuck key before operation. Power down and lock out the machine before changing bits. Use appropriate cutting fluid or coolant for the workpiece material to maintain cutting edge temperature and prolong tool life. Inspect the cutting edges and web for wear before each use; a dull or chipped split point significantly increases thrust and can cause workpiece damage.