Precision Twist Drill 6000159 Cobalt Drill Bit 1/4 in

Product Description

The PRECISION TWIST DRILL 6000159 is a cobalt jobber length drill bit designed for demanding metal drilling applications in trade and industrial settings. Ground to a 135-degree split point with web thinning, it starts on contact without center-punching and reduces axial thrust through the cut. The straight-cylindrical shank measures 1/4 inch in diameter and seats securely in standard keyless or keyed chucks. At 4 inches overall length with a 1-3/8 inch flute length, it fits most handheld and bench-mounted drill presses. Machinists, pipefitters, ironworkers, and HVAC fabricators reach for this bit when drilling through ferrous and hard materials where standard high-speed steel bits deflect or wear prematurely.

This drill bit is built for steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium — the material groups where cobalt alloy provides the heat resistance and edge retention that general-purpose HSS cannot match. It suits production drilling, field fabrication, and maintenance-repair applications where holes are sized to 1/4 inch finished diameter. The 2-flute spiral configuration evacuates chips cleanly in both through-hole and blind-hole scenarios. The oxide and bronze finish provides light corrosion resistance during storage and service.

Key Features

• Cobalt high-speed steel construction for extended tool life in hard and abrasive materials
• 135-degree split point with web thinning for self-starting, reduced thrust drilling
• Right-hand cut, regular spiral flute geometry for efficient chip evacuation
• Straight-cylindrical 1/4 inch shank fits standard drill chucks without an adapter
• Tapered web configuration adds rigidity and reduces deflection in deep cuts
• Meets NAS 907 specification for dimensional and performance consistency

Compatibility

Designed as an OEM-style replacement and general-purpose drill bit for use in any standard 3/8 inch or 1/2 inch drill chuck rated for 1/4 inch straight-shank tooling. Listed under Series R88CO-R89CO per manufacturer designation.

Installation Notes

Install in a drill press, handheld drill driver, or magnetic drill rated for the intended material and feed rate. Secure the shank fully into the chuck before operation and confirm chuck key is removed before starting. Apply cutting fluid or coolant when drilling stainless steel, titanium, or superalloys to manage heat buildup and extend edge life. Drilling without coolant into hard materials can blue the cutting edge and reduce tool life significantly.