Stainless steel is the basis of Filmar counterframes, an extremely versatile material that combines high structural capacity with excellent resistance to corrosion.
Stainless steels are characterized by a higher resistance to oxidation and corrosion, unlike normal carbon steels, which allows to maintain complete integrity even in the presence of high humidity rates that would otherwise affect the structure in a short time by forming iron oxide and causing the disintegration of the bonds that characterize the high strength of this material.
This capacity is mainly due to the presence of chromium, in the alloy, able to passivate and that is to cover itself with a thin and adherent layer of oxides, practically invisible of the thickness equal to a few atomic layers, which protects the surface of the metal or the underlying alloy, from the action of oxygen and external chemical agents.

How do I get passivation?
Passivation is an electrochemical process that through the application of a voltage allows a thin layer of chromium oxide to adhere to the surface of the metal and block contact with external agents (water and air).
It may happen, however, that the passivating film formed during passivation is not compact enough, so that the rate of corrosion decreases but does not cancel itself out, i.e. in this case the passivation process does not lead to the condition of total passivity.
In particular, to give rise to passivity conditions, the passivating film must have the following characteristics:
Compactness (i.e. low porosity): in order to block the diffusion of oxygen in the bulk of the metallic material;
Stability in the environmental conditions under consideration;
Very thin thickness, thicker films are in fact less compact;
Uniformity: it must uniformly cover the entire surface of the metal material; if, on the other hand, this layer does not adequately cover the surface of the material, oxygen has the possibility of reacting with the metal and the phenomenon of corrosion is not blocked.

For this reason, Filmar only uses stainless steel that has been certified and tested for its counterframes, in order to guarantee the highest level of quality over time.