Alfa Tool's High Speed Steel Aircraft Extension Drills are manufactured to NAS907, Type B standards. Extension drills allows users to drill areas beyond the reach of standard jobber length drills. Cobalt M42 high speed steel maintains cutting ability at temperatures exceeding 1000 degrees F. This heat resistance enables use in harder, high-tensile strength steels like stainless steel, titanium, armor plate, Inconel and other difficult-to-machine materials.