Induction hardening crankshafts. 5:11 video. Induction hardening around 1:45:
https://www.youtube.com/watch?v=wGVQHA-iVBQ
Previously:
https://www.homemadetools.net/forum/...0885#post73315
https://www.homemadetools.net/forum/...1800#post94762
https://www.homemadetools.net/forum/...057#post109427