Right. I think ALL commercially made dies are hardened. The reports I've seen of guys saying they don't need to be hardened were from guys who either reamed their own and didn't harden, or had their smith make them and didn't harden them.
I am of the opinion that they should be through hardened to provide more structural strength rather than just surface hardened. That is my opinion though.
I am of the opinion that they should be through hardened to provide more structural strength rather than just surface hardened. That is my opinion though.