#40 Cobalt Threaded Shank Aircraft Drill Bit – 1/2″ OAL – Stubby Length

Built for demanding aerospace, maintenance, and precision metal drilling applications, these M42 cobalt threaded shank aircraft adapter drill bits deliver exceptional heat resistance, durability, and reliable performance in stainless steel and other hard metals. Designed for compatibility with threaded drill systems, they combine secure tool retention with fast, accurate starts for professional drilling applications where precision matters.Features a 1/4-28 threaded shank for compatibility with Type D adapter style aircraft drill systems.Manufactured to NAS 965 Type D specifications for compatibility with threaded adapter-style aircraft drilling systems.Made from premium M42 cobalt high speed steel for superior heat resistance and extended tool life in tough metal drilling applications1/4″-28 threaded shank design provides a secure, positive connection in compatible drill systems for improved control and reduced slippage.135 split point tip starts quickly with reduced walking for cleaner, more accurate hole placement.Engineered for aerospace, aviation maintenance, fabrication, and industrial metalworking applications requiring dependable precisionPerforms exceptionally well in stainless steel, hardened steel, cast iron, and other difficult-to-machine metals.Manufactured to NAS 965 Type “D” specificationsWhen drilling low tensile strength materials, the Type “D” cobalt drill will have a significantly greater tool life than the NAS 965 Type B high speed steel adapter drills resulting in a much lower cost per hole.Frequently Asked QuestionsWhat are threaded shank aircraft drill bits used for?Threaded shank aircraft drill bits are commonly used in aerospace, aviation maintenance, fabrication, and industrial applications where secure tool retention, precision drilling, and reliable performance in metal are required.What materials can M42 cobalt aircraft drill bits drill through?M42 cobalt aircraft drill bits are designed for tough metals including stainless steel, hardened steel, cast iron, tool steel, and other difficult-to-machine alloys.What is the advantage of M42 cobalt over standard high speed steel drill bits?M42 cobalt contains a higher cobalt content than standard high speed steel, providing improved heat resistance, better wear resistance, and longer tool life when drilling hard metals.What is a threaded shank drill bit?What is a threaded shank drill bit?A threaded shank drill bit features a threaded connection at the shank end that securely attaches to compatible tooling systems, helping reduce slippage and improve drilling stability.