Precision Twist Drill 5996266 Taper Length Cobalt Drill Bit

Product Description

The PRECISION TWIST DRILL 5996266 is a taper length cobalt drill bit designed for high-performance drilling in demanding industrial and metalworking applications. Built to Series M51CO standards, it features a 25/64-inch (0.3906 inch) diameter, a 135-degree split point for self-centering entry, and a gold oxide finish. The cobalt construction provides increased heat and wear resistance compared to standard high-speed steel, making it well-suited for drilling harder and more abrasive materials. A tapered web configuration and web-thinned geometry reduce thrust requirements and improve chip evacuation. This bit is installed by machinists, maintenance technicians, and metalworking tradespeople working with drill presses, CNC machines, or hand-held power drills.

This taper length bit is used in production and maintenance environments where a longer flute is needed to reach deeper holes or clear chips more effectively than a jobber-length bit. The 4-3/8-inch flute length and 7-inch overall length make it appropriate for through-hole and deep-hole operations across a wide range of materials. Compatible material applications listed by the manufacturer include alloy steel, aluminum, aluminum alloy, brass, bronze, carbon steel, cast iron, copper, graphite, hardened steel, high-strength bronze, magnesium, magnesium alloy, malleable iron, nickel, nickel alloy, reinforced plastic, stainless steel, and steel. The straight shank fits standard drill chucks without adapters.

Key Features

• Cobalt tool material with gold oxide finish for enhanced heat and wear resistance
• 135-degree split point enables self-centering without a center punch on most materials
• Web-thinned, tapered web configuration reduces cutting thrust and improves chip flow
• 4-3/8-inch spiral flute length at a 6xD ratio supports deep-hole chip evacuation
• Straight-cylindrical shank fits standard drill chucks with no adapter required
• Right-hand cut, regular spiral; meets ANSI standards; heavy-duty grade construction

Compatibility

The 5996266 uses a straight-cylindrical shank with a 25/64-inch shank diameter and fits any standard drill chuck sized for that diameter. It is designed for use across the manufacturer-listed material range including alloy steel, stainless steel, hardened steel, aluminum alloys, cast iron, copper, brass, bronze, nickel alloys, magnesium alloys, malleable iron, reinforced plastic, and cermet. No coolant-through capability; dry or external coolant application only.

Installation Notes

Install and remove this bit with the machine fully powered down and locked out per applicable OSHA lockout/tagout procedures. Secure the straight shank firmly in the drill chuck before operation and verify runout is within acceptable limits for the application. Use appropriate cutting fluid or coolant applied externally when drilling ferrous metals or stainless steel to extend tool life and manage heat. Inspect the cutting edges before each use; cobalt bits can chip if subjected to interrupted cuts or excessive side loading.