'In any case, a metal crystalline structure is an entirely random thing - as a metal melt cools, crystalline regions form at nucleation points and they grow until they crash into the adjacent growing crystalline area.'      This is interesting, is it possible, at all, that this could cause an overall effect which resembles directionality in a cable? I only ask out of genuine interest and would appreciate any speculations as to anything that could cause this phenomena. Thanks Tones.