A permanent magnet is a piece of metal that holds onto magnetic properties outside the presence of an external magnetic field. Describing them as permanent is not quite accurate, however. Although "permanent" magnets are able to retain their magnetic properties, on their own, for long periods of time, these magnetic properties are subject to being weakened or even neutralized under certain conditions. For example, a permanent magnet is neutralized when heated to a temperature above the Curie point (see Resources) for that particular metal. To restore a permanent magnet, you need to cool the metal (if heated) and expose it to a magnetic field.
Magnetic Material , Magnetic Separator ,Magnetic Bar , Magnetic Material , Instructions
