Milwaukee 48-89-2521 Cobalt Jobber Drill Bit 4.9 in

Product Description

The MILWAUKEE 48-89-2521 is a cobalt jobber-length twist drill bit built for hard metal drilling applications. It features a variable helix design that starts at a 35-degree angle and transitions to 15 degrees, promoting rapid chip evacuation and reducing heat buildup at the cutting edge. The 135-degree split point tip provides a self-centering start and eliminates walking on smooth or curved surfaces. At 4.9 inches in length and metric-sized, this bit is suited for professional metalworking tasks where tool life and hole accuracy are critical. Licensed trades and metal fabricators rely on cobalt bits like this when standard high-speed steel falls short.

This drill bit is designed for use in hard and stainless metals including alloy steels, cast iron, and similar materials that generate significant heat during drilling. It performs in standard twist drilling applications as well, making it a versatile addition to a professional drill index. The metric sizing suits applications where metric hole tolerances are required. Suitable for use with corded or cordless drill drivers, drill presses, and magnetic base drills commonly used in HVAC, electrical, plumbing, and general mechanical trade work.

Key Features

• Variable helix angle (35 degrees to 15 degrees) promotes rapid chip removal and limits heat buildup
• 135-degree split point tip for precision self-centering start with no walking
• Cobalt construction rated for up to 10 times the service life compared to black oxide bits
• Integrated chip breaker geometry reduces heat at the cutting edge
• Secure shank grip design resists slipping in the chuck during high-torque drilling
• Metric sizing for applications requiring metric hole dimensions

Compatibility

Designed as a jobber-length cobalt twist drill bit compatible with standard 3-jaw drill chucks on corded and cordless drill drivers and drill presses. Suited for hard metal drilling applications across trade disciplines.

Installation Notes

This bit is installed by a qualified tradesperson into a compatible drill chuck secured finger-tight then fully tightened with a chuck key or via keyless mechanism. Always secure the workpiece before drilling and wear appropriate eye protection. Reduce feed pressure when the bit is breaking through the back side of the material to avoid grabbing. Follow applicable workplace safety standards and tool manufacturer guidelines for speed selection based on material hardness and bit diameter.