Thank you for that info, it's much appreciated. If time allows, I will experiment with a scrap rotor we have laying around and use all methods you mentioned, thanks.
A little background: Inspection room is kept at 20 C +/-2 C. Temperature gauge is accurate to +/-.5 C. Outside ambient temperature where parts are kept can vary from 5 C to 38 C. One part in particular is a rotor made of 4340 steel, ~2350mm long, average diameter of 115mm, and weighs ~ 650lbs...