Have you ever seen one of these vintage hand forged C clamp before? This week I made one out of scrapyard steel 14x28mm stock and M8 threaded rod.
I had some trouble making the handle because I wanted to have it all forged but as it turns out I’m not quite able yet… In the first attempt I quickly realized there wasn’t enough material on the threaded rod to make a strong connection. So I tried to forge a coupling nut! It was coming together well but at the end I think I’ve closed the pin too hard so I broke the handle piece trying to free it up. At the and as always third time’s a charm I took out my cheap stick welder and I fabricated the handle pieces without forging. I’m still very happy with how it tuned and I’m pretty damn sure doing it this way is so much stronger than the other methods I tried.
I’ve done a rough test about the force that this clamp can sustain with a bathroom scale and a mechanical advantage gij. I was able to twist the handle to around 3.6kN that is around half the threaded rod shear strength for my effective length of engagement. Nothing too scientific, but still way more force than any of my other clamp can apply and the frame hasn’t deformed at all.