A “U” shape tends to concentrate the stress in the curved part of the U.Our Horseshoe magnets are predominantly used in classroom settings as they are great for teaching children how magnetic fields operate and the difference between the north and south poles. We also don’t provide “U” shape neo magnets because neodymium magnet material is so hard and brittle. Why pay for the added expense of all that unnecessary added neodymium magnet material? You can put two magnets side by side, or use a steel structure like our Mounting Magnets do. If you want the improved (pull-force) strength of having two poles near each other, you don’t have to resort to a horseshoe shape. The traditional iron horseshoe magnet, so shaped to avoid demagnetization in its own demagnetizing field, is now a museum piece. It wouldn’t demagnetize them any more than having a single magnet sitting on the shelf. In fact, they can be stored with two neodymium magnets repelling one another. Neodymium magnets do not need a horseshoe shape or a keeper. The whole motivation for making magnets in a horseshoe shape (increasing coercivity) is basically irrelevant. To demagnetize a neodymium magnet, you really need a stronger magnetic field than a neo magnet can provide. It’s part of what makes them so amazing.Įxcept for a few cases (involving high temperatures or very thin magnet shapes), neodymium magnets generally won’t demagnetize each other. Unlike the Alnico magnets discussed before, they generally don’t demagnetize themselves. They also have a much higher coercivity than other magnet types. You can find a stronger magnetic field around them, compared to other types of magnets. Find other pole identifying products here.Ĭan K&J provide neodymium magnets in a horseshoe shape? The red and black plastic coated magnet is the handy D68PC-RB magnet. The electronic pole identifier can be found here: EPID2. We could also have used the larger HS2 for the same demonstration. We’re using the HS1 Alnico magnets available in our Horseshoe Magnets section, and magnetizing them with some strong, DAA neodymium cylinder magnets. In the video below, we show how to re-magnetize a horseshoe magnet. How to remagnetize an old horseshoe magnet It helps the magnet not demagnetize itself even more than without the keeper. The use of a steel keeper on a horseshoe magnet is another step in improving this kind of performance. With an earlier magnet material like Alnico, you couldn't use a thin disc shape like we can with neodymium magnets. A horseshoe shape is chosen so that the magnetic material can stay magnetized. It changes the load line (or Permeance Coefficient) of the magnet, so that the magnet is not tending to demagnetize itself. We discussed the influence of shape on magnetization in some detail in our in-depth article about Temperature and Neodymium Magnets.Ī horseshoe shape is kind of like a more extreme version of a long cylinder. For example, the magnets used in door and window alarm sensors are usually long, cylindrical Alnico magnets. This idea is commonly used with low-coercivity magnetic materials, such as iron or Alnico magnets. For example, a long cylinder shape stays magnetized better than a thin disc. Taller shapes operate "above the knee" and avoid demagnetizing themselves.Įven with the limitations of early magnetic materials, there are ways to improve coercivity: the “staying-magnetized” performance. Three load lines are shown for different magnet shapes in free space. If getting 2 poles together were the only goal, why not put two disc magnets or blocks side by side, and not waste all that extra magnet material going around a large “U” shape?Ī big reason for the "U" shape is to avoid demagnetization with older magnet materials.Ĭoercivity: How strong does a magnetic field have to be to demagnetize a permanent magnet? In fact, we’d say that more pull force is not the primary reason for the U shape. This really isn’t the whole answer, though. Even the magnet-in-a-steel-cup design of our Mounting Magnets gets more strength using this basic idea. This includes the alternating magnets of the Magnetic Knife Holder and the alternating poles of magnets used in Magnetic Spice Jars. We've shown a few examples using neodymium magnets with opposite poles right next to each other, though not in a complete horseshoe shape. Using two poles right next to each other like this can be a great way to get a strong hold. Notice the larger, stronger magnetic field within the steel from the horseshoe. Comparison of horseshoe and cylinder magnets stuck to a steel plate.
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