Torsion Bars

I am referring to a car driven under normal driving conditions. I am not referring to racing or modified cars. I have been working on mopars since 1966, and I have never seen a bar break from a score.

so I strongly disagree with your concept of what a score is.

bars do go flat, or get badly gouged, and sometimes break as a result. They do get scored, but don't break. and as you said,,a bar is not fragile, so a guy really has to try hard to damage a bar bad enough to break as you describe.