INOXIDISABLE (STAINLESS)

A Material that is Inoxidisable (stainless) resists oxidation and corrosion, meaning attack by oxygen, humidity, and many chemical agents. In watchmaking, the term most often refers to Inoxidisable (stainless) Steel, an Alloy of Iron, chromium (at least ~12%) and other elements (nickel, molybdenum), whose resistance comes from a thin protective layer of chromium oxide that spontaneously reforms if scratched. The most commonly used Inoxidisable (stainless) Steel for cases and bracelets is 316L, valued for its corrosion resistance, its Hardness, its suitability for Polishing, and its good skin tolerance; some brands use 904L, which is even more resistant. Inoxidisable (stainless) does not mean indestructible: the metal remains subject to scratches and, in very aggressive environments (chlorine, prolonged exposure to sea water), to localised corrosion. The inoxidisable property is essential for the External parts (case, dial, hands), exposed to perspiration, water and impacts. Not to be confused with “Scratch-resistant”, which relates to surface hardness, not corrosion.