In line with some of the videos on the subject I saw, I shaped the clip to the form I wanted and then basically baked it as high as my toaster oven would go (500-550F) for 1.5-2 hours. I then polished (polishing doesn't work well when dead soft). That's basically all that's needed. I don't believe sterling silver is even capable of being hardened, so I think the Argentium is a good choice.Cool, thanks. How did you harden it?