I just bought a set of tools consisting of a metal stretcher and a shrinker. They work unbelievably well. The problem is they leave marks on the metal due to serations on the jaws. I was wondering if anyone has a stretcher/shrinker with smooth jaws, and how well it works. I could grind off the serations and if I lost 3/4 of the ability to stretch/shrink, it would still be acceptable since it works so great now. But if they don't work at all with smooth jaws, I won't bother.