Friends: Lets say you have a conductor that is made of two components - an inner core of steel and an outer layer of aluminum (ACSR). Is there mutual inductance between the steel and the aluminum? Every example of mutual inductance I have seen requires that an insulated wire be wrapped around some core. In this case, the steel and aluminum are not insulated. Bare aluminum forms a tubular cylinder around the bare steel. They are touching. I appreciate any ideas! Thanks.