1. M18*6/P1.5 thread shank(inside). Suitable on Fein Magnetic drills.2. Made of super tough high speed steel., e.g. M2, M2AL, M35, M42, ASP2030 etc. And can be used on various materials, like steel plate, Copper, aluminium, cast iron, stainless steel and plastic.multi-plycutting end edge geometry,...