I have to take the blame.
I've looked closer at the pictures, and I can see a casting line.
So they are brittle cast metal, that I told you to bend.
The one's I had were much thinner and not cast. Yours look like something from car audio; cool looking though, and nice job. Except for the breaking part...
I think Doug has a good idea with a round file or a Dremmel; but don't listen to me it was Doug's idea.