Stainless steel and chromium oxide layer

[PatrickP2]

Stainless steel has a protective layer on its surface, which is 3-4 chromium oxide atoms thick. How is it possible that such a thin layer does not rub off immediately when we touch it?

 

[jack action]

It most likely rubs off immediately but it is recreated in a matter of nanoseconds according to this article.

The chromium oxide layer forms on the stainless steel surface when chromium reacts with oxygen. This happens instantly, with formation speeds measured in nanoseconds [...]

 

[Flyboy]

Aluminum does something similar.