I've got a threaded shaft stuck in a socket it screws into. The socket is
in a plastic house which encloses a small, solid state circuit board.
I need to get the shaft unscrewed. The shaft seems to have a nickel or
chrome plating on it. The socket looks to be aluminum or stainless. No
obvious signs of corrosion, but the shaft doesn't want to come loose with
moderate torque from my wrench. Heat and mechanical shock are out because
of the circuit board.
Looks like I'm going to have to chemically loosen the joint. What's the
best product to use for this type situation?