After assembling a jig to make the lower bends for a homeade receiver, I tried it out on a piece of .05" 4130. It seemed to work OK except for three tears, each about an inch long, located right on the bends.
The jig is very similar to the one described on this site:
My digital camera has horrible picture quality otherwise I'd post photos. What can I do to keep the metal from tearing? I was thinking about trying some grease, but I want more opinions before I go ruining another piece of my 4130.