Denis G. wrote:
Ok, I understand. I've cut some transformers like that, but I thought
that he was cutting an MOT in half to make two electromagnets. I
guess it not really necessary to cut it exactly in half, but I'll
probably have to find a few MOTs to experiment with. Thanks.

Aye, once you remove the "I" section, the magnetic flux lines don't have a
continuous path back into the "E" laminations, so they extend out into
space, creating a magnetic force which extends outside of the core.

Jon