METALBLACK is a cold chemical burnisher, active on ferrous metals like cast iron and steel. It carries out its action within 1 and 2 minutes according to the type of treatment, forming an even black finishing boasting good resistance against corrosion.  It does not alter the geometry and sizes of the treated object. It is ideal for treating cutting tools, reamers, files, drills, screws, bolts, gears and metal tools. This type of burnishing is safer for operators compared to hot burnishing, since no harmful and corrosive vapours are formed.