Neodymium Earth Magnets - The World's Strongest Permanent Magnets

Take two neodymium earth magnets and place one in each hand.  Each magnet might be about the size of a dime.  Grab each magnet between your thumb and index finger and squeeze them tight.  Now slowly bring your hands together.  As your hands come closer to each other, you will begin to feel something pulling them closer to each other.  When your hands and the neodymium magnets are about 6 inches apart, the force will start to intensify.  Bring them just a little bit closer together and the magnets will "jump" from your hands and stick to each other.  You will have a very difficult time trying to pull them apart.

That is the power behind these magnets that were discovered about 40 years ago in the 1970s.  There are actually two types of rare earth magnets.  The first rare earth magnet was made of an alloy of samarium and cobalt and hence the name samarium-cobalt magnet.  A few years after scientists perfected the samarium-cobalt magnet, they began working on today's most powerful and popular permanent magnet, the neodymium magnet.


The neodymium magnet has certain attributes that cannot be found in any other permanent magnet.  Ounce for ounce or pound for pound the combination of neodymium, iron and boron gives this magnet more remanence or strength through the magnetic field.  As a comparison, an NdFeB magnet has a remnance of up to 1.4 while a ferrite magnet is rated with a remanence of .2 or about 1/7 the power of the neodymium magnet.  Stated another way, you would need a ferrite magnet 7 times the size and weight of a neodymium magnet to have roughly the same strength.

As you can see, the incredible power of these magnets allows them to be made very small and still be very useful in numerous types of applications.  When you pick up a battery powered drill or other portable power tool, chances are very good that a neodymium battery helps power that tool.  Stereo speakers and headphones also rely heavily on these permanent powerful magnets. Other applications include use in computer hard drives and as the source of power in flashlights that you shake to illuminate.

Some of the different styles of neodymium earth magnets include those shaped like discs, cylinders or rings.


The disc is by far the most common rare earth magnet and is used for holding two surfaces together (closure) and for keeping metal display signs in place in or on retail store fixtures.  There are many other applications, limited only by one's imagination.


The rare earth cylinder or rod-shaped magnet is taller than their diameter and they are sometimes used as a stud finder.


Ring earth magnets are shaped like a metal washer.  A circular ring with a hole in the center, they are often encased in a metal holder and they make excellent magnets for metallic hooks.


Finally, when working with neodymium earth magnets, you need to take care not to get your fingers pinched between two magnets because the pain can be intense.  With the larger earth magnets, there have been more than a few cases where people have had bones in their hands and even their arms snapped by the amazingly powerful magnets.  These magnets are not toys and should be kept away from small children.