Precision Twist Drill 5996040 Cobalt Aircraft Drill No 30

Product Description

The PRECISION TWIST DRILL 5996040 is a cobalt aircraft extension drill bit designed for precision drilling in hard metals and aerospace-grade materials. Built to Series CO501-6 specifications, this No. 30 wire gauge bit measures 0.1285 inches in diameter with a 135-degree split point that self-centers on contact, reducing walking and the need for a center punch. The extended 6-inch overall length allows access to deep or obstructed bore locations. The straw finish indicates heat treatment and provides light corrosion resistance. Licensed tradespeople and aerospace MRO technicians are the primary users.

This bit is suited for drilling stainless steel, high-strength alloys, titanium, and other materials that generate high heat and work-harden standard HSS tooling. The 6-inch extension length is specifically beneficial in aircraft structural repair, deep fixture drilling, and applications where standard-length bits cannot reach. The right-hand spiral flute design and web-thinned tapered web promote efficient chip evacuation in deep-hole applications. General-purpose performance rating makes it appropriate across a range of industrial and MRO drilling tasks.

Key Features

• No. 30 wire gauge size, 0.1285 inches diameter for precision-tolerance hole sizing
• 135-degree split point with self-centering geometry eliminates pilot hole requirement
• Cobalt construction withstands high heat generated by hard and exotic metal drilling
• 6-inch overall length provides extended reach for deep or obstructed drilling locations
• Web-thinned tapered web reduces thrust and improves chip flow in deep holes
• Straw finish offers light oxidation resistance and indicates proper heat treatment
• Meets NAS 907 Type J standards for aerospace and industrial applications

Compatibility

Designed as a general-purpose cobalt aircraft extension drill bit conforming to NAS 907 Type J, compatible with standard drill chucks and collets accepting a 0.1285-inch straight-cylindrical shank.

Installation Notes

This drill bit is intended for use by machinists, aircraft maintenance technicians, and skilled tradespeople operating drill presses, hand drills, or drill motors. Secure the workpiece firmly before drilling to prevent movement on bit entry. Use appropriate cutting fluid or lubricant when drilling hard alloys to extend tool life and maintain hole tolerance. Inspect the cutting edges before each use and replace if chipping or dulling is present, as a damaged cobalt bit can fracture under load.