iron bar
Depending on how long your pieces need to be I can only suggest getting quotes for a water jet or perhaps a horizontal mill using slitting saw cutters.
I have an old horizontal mill although have never tried cutting iron with thin cutters. Perhaps the machine costs would be more...
electrical iron
I sometimes build electromagnets for customers and get 1" rod from carpenter metals for this purpose which they call simply electrical iron. My understanding is that it is very low carbon.
John Hewitt
Custom Research Equipment