Magnetizing

With just a few exceptions, when magnets are manufactured they finish the process in the un-magnetized condition. That means the magnetic domains are randomnly oriented within the body of the magnet so that there is no net external field.

In order to make the magnet exhibit an external field, we apply a strong field to the magnet, rotating the domains within the magnet so they all point in the same direction. The source of the external field can be another magnet (sometimes used for Alnico), a solenoid magnetizing coil, a fixture shaped to provide the specific pattern of magnetization specified by the customer or it may be the field generated between to poles of a powerful electromagnet. The duration of the applied field can be as long as several seconds or as short as 5 milliseconds. Shorter durations are typical when the applied field has to be extremely powerful.

Arnold has all of these techniques available. Solenoids and matching power supplies are available for magnets up to 6" in diameter and up to 8" long. Multiple-pole magnets require specially built fixtures.

The cost of magnetizing fixtures for multiple pole magnets can be several thousand dollars. Many times, it is possible to build a prototype fixture (for lab use only) to magnetize sufficient quantities for engineering evaluation.

Contact Arnold to discuss your magnetizing needs with our trained staff.