Precision Twist Drill 5996589 Taper Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5996589 is a cobalt taper length drill bit built for heavy-duty drilling in demanding materials. The bit measures 0.8125 inches (13/16 inch) in diameter with a 10-inch overall length and a 6.125-inch flute length, giving it the extended reach that taper length geometry is designed for. The 135-degree split point with notched, web-thinned construction reduces walking and thrust at startup, allowing the bit to self-center without a pilot hole. The spiral flute runs in a right-hand cut direction with a regular helix profile and a 6xD flute-to-diameter ratio that helps evacuate chips efficiently. This bit is suited for licensed machinists, maintenance technicians, and fabricators working in production or job-shop environments.

This drill bit is designed for use across a broad range of materials, including alloy steel, carbon steel, hardened steel, stainless steel, cast iron, malleable iron, aluminum, aluminum alloy, brass, bronze, high strength bronze, copper, nickel, nickel alloy, magnesium, magnesium alloy, cermet, graphite, and reinforced plastic materials. The cobalt construction maintains hardness and edge retention at elevated cutting temperatures, making it well suited for interrupted cuts and high-strength workpieces where standard HSS tooling degrades quickly. The straight shank fits standard drill chucks without adapters.

Key Features

• Cobalt tool material for heat resistance and extended edge life in hard and abrasive materials
• 135-degree notched split point with web thinning for self-centering starts and reduced thrust
• Taper length geometry — 10-inch OAL with 6.125-inch flute — provides reach beyond standard jobber length
• Right-hand spiral flute with 6xD ratio promotes efficient chip evacuation in deep-hole applications
• Straight shank at 0.8125 inches diameter fits standard drill chucks without a reducer sleeve
• Meets ANSI standards; rated heavy-duty grade for production and maintenance applications

Compatibility

Designed as a heavy-duty OEM-style taper length drill bit in the M51CO series, compatible with any standard drill chuck or drilling machine that accepts a 0.8125-inch straight shank.

Installation Notes

Installation and use of this bit should be performed by qualified machinists or maintenance technicians familiar with drilling equipment and safe machine operation. Ensure the drill press, lathe, or hand-held drilling tool is fully powered down and secured before mounting or removing the bit from the chuck. Verify chuck jaw grip across the full shank diameter and confirm runout is within acceptable limits before beginning a cut. Use appropriate cutting fluid or coolant for the workpiece material to preserve edge life, and follow applicable workplace safety standards for machine guarding and PPE.