Do steels lose their sharpness even if not used?

[SCWillson]

Can the edge on a knife lose its sharpness even if it's not used and is stored properly?

 

[seelow123]

I don't see why it would unless it was a carbon steel and rust got to the edge.

 

[FortyTwoBlades]

From any technical standpoint, yes they do. Micro-corrosion of the edge widens the apex over time. But with a stainless steel or a carbon steel given some form of stable long-term storage treatment it'll be so little as to be undetectable. Try shaving with vintage "new old stock" double edged razor blades and you'll see the principle in action--even with stainless blades from 20 years ago the shave won't be as smooth or comfortable in most cases.