340 Crankshaft bit the dust

Newbie crank question but didn't factory cranks have surface hardening on the journals which would get removed if the journals were ground undersized? Or was that just 426 Hemi crankshafts or something?
Industro stuff, 413 ind. Had what was described to me as flame hardened journals. If it was something they did and did to all industrial/special app motors... idk.