The normal method of demagnetisation is to subject the part to an oscillating magnetic field that uou gradually reduce the amplitude of. Typically the last part is done by pulling the part away from whatever is generating the field. I don't know the parts you need to demagnetise, but a typical home-made demagnetiser soncists of a medium-sized mains transformer that the core has been removed from, and then all the 'E' laminations re-iserted facing the same way. You connect it to the mains with a light bulb in series (the inductance will be much reduced by the open core, so the impedance will also drop and the current go up), then put the parts on the open face of the core, turn on the current and pull the parts away to arm's length. Only then do you turn it off. Can you still buy tape bulk-erasers? That would work too. Old books on watch repairing have various designes for demagnetisers in them. If the book is old enough, it won't assume the availabity of AC mains. There were designes using vibrators (no, not _that_ sort of vibrator, the thing that was used to chop the DC supply from a car battery in a car radio so you could feed it into a step-up transformer to get the B+ for the valves). There were designes using rotating permanent magnets (and woe betide you if they came loose!). -tony