Before annealing the rod wire in a furnace with inert gas
atmosphere the material becomes pickled mostly, to remove the scale arisen when
rolling. An insufficient pickling leaves rest of scale on the surface. If the wire
is then drawn, these rests of scale can be pressed in in the material. On the surface
of the drawn wire shinier places, in the areas with the scale rests, can be stated.
6,00 mm round - pickled , spheroidised
following drawn at 5,00 mm