The self-healing properties of stainless steel

I have made pretty significant scratches on my Panerai over a short period of time, which has caused me to stress about it and look for potential fixes.

But without doing anything in particular, I noticed that after a few days, some of the scratches had almost entirely disappeared, leaving just a faint mark. This made me wonder, is stainless steel actually capable of healing itself?

Turns out it is. Website explains:

Due to the alloying elements in the stainless steel, a thin, transparent “passive layer” is formed on the surface.

Even if the stainless steel surface is scratched or damaged otherwise, this passive layer, which is only a few atoms thick, instan- taneously reforms under the influence of oxygen from air or water.

This explains why stainless steel does not require any coating or other corrosion protection to remain bright and shiny even after decades of use.

This won’t be enough to fix the massive scratch you can see on the picture above, but it is enough to fix smaller scratches of everyday life.

Another interesting remark I made myself is that the stainless steel of my Omega Seasmaster Aqua Terra doesn’t seem to have as good healing properties of my Panerai. Could that be due to the different alloy used to make both stainless steel cases? I’m definitely no engineer but that could explain why.