I've been carrying the PocketToolX the last few days. We've been driving posts, replacing fencing that's 20 years old. Anyway, it's been hot and humid here in the mid-Atlantic, so this becomes hot, sweaty work.
Needless to say, the Piranha has been exposed to a lot of sweat.
I thought 154CM was supposed to be relatively good stainless steel. This is from 2 days of sweaty EDC:


I actually don't mind it as a patina, but I was surprised how quickly it appeared.