Doubled Dies: Class II (Distorted Hub Doubling):

Class II is harder to find empirical evidence to conclusively prove the cause of the Hub Doubling. The doubling is speculated to relate to either the Die or the Hub, either expanding or contracting too much in relation to the first hubbing during the annealing or tempering processes.

Dies are annealed (cooled slowly) to make them softer or more susceptible to taking an impression of the Hub. The Hub in contrast is tempered, quickly cooled, so that it is more durable and does not distort while transferring an image to the Die. If for whatever reason, either the Die or the Hub were not to return to its normal size in between hubbings, doubling could result like the below image, where doubling would be more pronounced toward the rims and would either be spread away from or towards the center of the die.