Voltage Difference Between Machine Laminations
The voltage producing eddy-currents in electric machinery and transformer laminations does not seem to be discussed in electric machinery and transformer texts. Where the lamination insulation is discussed, the focus seems to be on the mechanical properties of the material and maintaining material integrity. The implication seems to be that the voltage is very low and that minimal insulation property is required, but maintaining mechanical integrity is essential. Oxidation produced by annealing is sufficient in terms of insulation voltage, but other materials are used for their thermal and mechanical durability.

The procedure for determining the voltage across the insulation seems to be to apply Maxwell's equations to the core prior to dividing it into slices by construction using laminations.