Lets say you started with a round bar and bored it outWhich aluminium would give stronger walls, less likely to dent?
As long as you don't intend to do some welding on the piece later, you may use a 7xxx series alloyThis is aluminum alloy armor though so if you would have a hard time looking for it you just have to settle with the more common 6061 - T6These so far are among the hardest type of aluminum alloys.
