Pretty sure uninformed/Sergio has hardness tested the arms.
I'll give him a ring or PM him about this thread.
There was a Kiwi bloke that had tested them pre and post bending (IIRC he used a large forge for heat) and again, IIRC there was bugger all difference in hardness after bending.
He had a good site on how he went about it but I can't find it ATM.
I'm not sure why you don't think the bottom one's been heated and bent ?

