Some years ago, I sorted wheel weights by giving each one a pinch with a (sharp) pair of side cutters. I seem to recall that most were quite easy to cut and a few were so hard that I could barely put a scratch on them. I assumed they were zinc. This was a few years ago and I'm fairly sure the really hard ones were not steel.
Recently, I sorted some more wheel weights and I came across some that seemed much harder than lead, but I was still able to cut them with heavy pressure.
I realize none of this is very "technical," but just how hard are zinc wheel weights? Can they be cut with side cutters??