Neodymium magnets are some of the strongest magnets in the word due to their composition, which includes iron and boron. When handling neodynium magnets, you need to use caution because their pull is so strong that they can damage themselves when they snap together. Larger magnets can even bruise skin or break bones if your finger gets caught between them. Neodymium magnets can also affect credit cards, computer disks and anything else with a magnet field. Neodymium magnets can be used to remagnetize old magnets so they will hold strong once again.
- Tie one end of a piece of string around the center of a bar magnet. Tie another piece of string around the center of another magnet. Dangle the string so the magnets can rotate freely. The north poles will point north. Check by bringing the north poles together; they should repel one another.
- Hold a compass near the magnet. The needle that usually points to the north will point to the south pole of the magnet
Find the neodymium magnet's poles using one of these methods:
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Stroke or rub the north pole of the neodymium magnet along one side or end of the old magnet.
Stroke or rub the south pole of the neodymium magnet along the other side or end of the old magnet.
This method works best for old fashioned horseshoe magnets or bar magnets.