[Talonmotorsport]

What you probably have there is a strip cut from a hot rolled sheet. If the edges are a crisp cut don't even bother to try and put a 90 degree bend in it. We used to have this problem alot at the sheet shop and in fabricating uprights for various things. If in doubt go for 40x3 bright mild cost a fair bit more but at least it won't do that!