Corrosion Resistance of A-2?

[cotdt]

How corrosion resistant is A-2? I know you can get a patina easily because I've had this issue, but what about pitting rust? If you leave it sitting outside for a week, how bad would it be?

 

[theonew]

I have a little A2 blade in a kydex sheath that I got from one of the makers here. I keep it in a first aid kit I take hiking and camping. On one rainy trip I opened the kit for some gauze and tape. I thought I was careful but apparently some water got in. About 10 days later I took the knife out and there was a patch of rust that wrapped around the edge on both sides. The part of the edge that was rusty was still shaving sharp. There was no pitting at all and after about 10 minutes with some Flitz it was shiny again.

 

[cotdt]

I have a little A2 blade in a kydex sheath that I got from one of the makers here. I keep it in a first aid kit I take hiking and camping. On one rainy trip I opened the kit for some gauze and tape. I thought I was careful but apparently some water got in. About 10 days later I took the knife out and there was a patch of rust that wrapped around the edge on both sides. The part of the edge that was rusty was still shaving sharp. There was no pitting at all and after about 10 minutes with some Flitz it was shiny again.

Thanks for the very useful response. Sounds a lot like M2/M4. They get some surface rust but doesn't pit, and the edge stays sharp despite the rust.

 

[Ben Dover]

A-2 is a carbon tool steel. It has very little corrossion resistance.