These are made of wear resistant highly compressed fine granular tungsten. They are intended to be used for milling to fine tolerances. For use on steel,cast steel, non-ferrous metals, plastics and extremely hard materials. They may also be used for technical work, for engraving and milling of PC cards. It is advisable to secure workpieces well to ensure, vibration free milling, high accuracy and avoid accidents. The shank diameter is 3.0mm.