How do I Recharge a Steel Bar Magnet?

The Earth's magnetic field can restore your bar magnet.

A steel bar magnet naturally loses its magnetism slowly over time. If your magnets have become weak, a strong magnet will revive them. You'll need a neodymium permanent magnet or electric magnet recharger. The Earth's magnetic field can also recharge your magnet.

Permanent Magnet

Take a neodymium magnet and stroke its south pole over the north pole of your bar magnet, from the center to the pole. Once you reach the north pole, remove the magnet and bring it back to the center. Repeat the outward stroking a few dozen times. Perform the same motion with the north pole of the neodymium magnet over the bar magnet's south pole.

Electric Magnet Charger

An electric magnet charger has two hollow vertical coils. Slip the bar magnet inside one of the coils so its poles match the north and south pole markings on the coil. Plug the charger in and turn it on for 30 seconds.

Earth's Magnetic Field

Use a compass to find magnetic north, then place your magnet with the north pole pointing south. With the magnet on a sturdy surface, hit it several times with a hammer. Wear protective goggles in case a piece breaks off.

References

• K & J Magnetics: Uses for Neodymium Rare Earth Magnets
• Old Engines: Magnet Charger Page
• Argonne National Laboratory: Recharging Magnets