Just occured to me that I've been carrying a small fire steel on my keychain for about a year now. I remember leaving the heat shrink tubing off on purpose, to see what would happen. So far, it looks just about like it did a year ago. I use it occasionally, either to play with it or (usually) to start the fire when I'm grilling.

This is only a single data point, and my pocket is probably an ideal environment (never wet, hardly ever humid, since I'm only ever at work or home or some other air conditioned building). I'm also assuming that any corrosion would be at noticeable.

Anyone else carry one this way?

Note that this is probably a much different situation than storing a fire steel long term in a container of some sort.

i got one on my keychain in uncoverd condition. I did replaced my old one, with a new one because it was a bit worn out. Never had corrosion signs on either of them.

I carry mine protected with a plastic tube for about five years. It does not keep moisture away but reduces wear. The rod got wet a few times from rain, sweat and a cycle in the washing machine (not on puprpose). The surface shows light oxidation. Once fresh surfaces turn grey the oxidation stops.

All of mine have a very thick coating of clear nail polish which i reapply after each use so I cant really say.

I'm beginning to wonder if that's necessary. I'm sure if a firesteel was stored in a wet / very humid environment, it'd corrode. But pocket carry? I like to use mine... practice with it. So far, it looks like you can leave the shrink tube and nail polish off and it's fine over the long term.

I never have used nail polish on either of my BSA Hotsparks that I carry in my pocket and keychain and they are fine. Have carried them for about a year, but I live in Arizona so it is generally hot and dry.

I keep mine covered, but only so they don't discolor clothing.

I keep mine covered, partly to keep striker, rod and tinder together and partly to prevent them scratching other things in my pocket.

I live in Phoenix and carry mine in my pocket. I have never had a problem with corrosion.

Hi again,
as far as adverse effects on a firesteel goes, I own 1 scout version which has been around my neck for a good 15+ months for 6-10 hours a day.... and 2 army models, 1 in my coat pocket with the rest of PSK and 1 in my camping/BOB.
I have just started in non destructive testing and whilst in training I have subjected all 3 to a fluorescent dye penetrant test. Under inspection, none of them has shown any 'pitting' (small holes) so nothing has leached out into clothing or even my skin. No big deal but I do sweat a lot as I'm a hairy fitness instructor. so when I say sweat, even when I don't exercise, I sweat.....blah blah etc
Summary no damage to mine except where I have run BK10/Leatherman blades on them when I've been playing