The magnet sticks to fork stanchions, so I guess they are not aluminum. I did install the torque washers that came with the kit.
As I stated in the other thread, I meant the lowers since that's where the axle is retained by the dropouts during operation. They have always been aluminum in my experience (although probably there are some steel ones). The relatively soft aluminum dropouts need to keep the axle flats from rotating during operation and have failed at times.