[350HP930]

Hey snow, I am an engineer but I will give you a good real world example of why temperatures can vary greatly between adjacent metals.

Take a thick metal rod, hold one end with your hand and put the other in a hot torch flame. I guarantee you can melt one end before the heat can even start to flux to the end where your hand is located. Temperature variances can be great even across a solid block of metal, let alone different metals with material boundries.

To top off this debate I am currently working as a machinist again which involves a lot of broken bolt and stud removal. I also have to remove a lot of press fit gears. Do you think that involves heating the gear or the shaft?