Beaver, crankshafts are not the same alloy as engine blocks, heads, etc. Nodular cast iron has a different grain structure, and yes, it bends. It can't be forced into a right angle, or anything like that, but we're talking about a deflection of a few thousandths, maybe the thickness of a couple of strands of hair. A sharp blow with a soft, blunt object like a lead hammer will definitely take a minor bend out, and I've done it as a routine part of regrinding or rebuilding damaged crankshafts. What's your engine machining background? I've been doing it for a little over 40 years.
Jerry
