But we are not actually clamping on the thin walls. As I said before we are not allowed to do that because we found out the hard way what happens when we do. The part that we clamp on is the "hat" and it's mostly solid all the way through. These parts have been hardened also so if anything is deforming it is the soft jaws. Of course, we could use harder jaws but then we risk marring or scratching the parts instead.