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Do Neodymium Magnets Wear Out?

Magnets, like most products, weaken and wear out. Magnets lose their magnet strengths when exposed to unfavorable environmental conditions or brought in contact with adverse materials that affect their magnetic field intensity. The magnetism of most magnets is a permanent feature, but a magnet can be demagnetized for specific periods, short or extended. And if magnets can be stripped of their magnetism, they can equally wear out.

The magnetism of a material affects its relevance across different applications, including in sensors and MRIs, as well as its study in fields related to electromagnetism and physics. Imagine a solar inverter with a poor recharge rate or a vacuum cleaner that powers off every few minutes. Magnets with weak magnetism underserve the essence of purchasing strong Neodymium magnets. To prevent your magnets from depleting in magnetism, store them in a cool place and in pairs, keep them from hot temperatures, and protect them from non-ferromagnetic spaces.

To learn more about the weakening of magnets and prevention methods, continue reading this article.

How do magnets become weakened?

Each magnet differs in strength and durability from the other. Neodymium magnets, some of the strongest magnets made, are cut across a range of grades, highlighting the variance in magnetic strength and intensity. Yet, even neodymium magnets are subject to weakening or wearing out. Here are some reasons why this could happen:

  1. Age: At manufacturing, the shelf life of any magnet is timeless. A well-made magnet should last as much as two decades without being degraded to a non-magnetic state. The degree of this degradation, if any, depends on the storage conditions of the magnet and the different processes or applications for which the magnet has been used. You may not notice the reduced magnetic strength, as the loss in magnetism tends to be a subtle process rather than a sudden one.
  2. Exposure to extreme temperatures: An average magnet has a maximum operating temperature corresponding to its grade. If a magnet is brought into an environment outside this maximum temperature, it loses its magnetic effect and becomes non-magnetic. In industrial applications, most magnetic substances are kept within their temperature range. Different neodymium magnets are rated based on the maximum temperatures they can withstand. Thus, an “SH” magnet designed to operate at 150C will be adversely affected if used in processes operating at 200C. To prevent this, manufacturers assign ratings to magnets to serve as guides for users.

Loss of magnetism also occurs with very low temperatures. When a magnet is subjected to temperatures below its operating range, it reduces magnetic strength; most of this magnetism is restored once the magnet is withdrawn from the low-temperature environment. However, very high temperatures may result in a permanent loss of magnetism.

  1. External Charges: A magnet’s strength corresponds to its magnetic field’s intensity. The magnetic field intensity, or flux, can be altered when specific external charges are exerted on the magnet. Magnets that are unshielded from these charges experience a reduction in magnetic strength. This is particularly true for some magnet types, such as Alnico (which is why Neodymium magnets are considered the best choice for any industrial application).

When magnets of opposite fields are in close contact, their overall magnetic strength can be affected. Storage of magnets should be done such that opposing field contact is reduced. Coils and other substances capable of inducing sharp electric effects can equally affect a magnet’s strength. Though most magnets resist trauma, damage to a magnet’s shape will ultimately yield lower magnetic strength.

Do Neodymium Magnets Wear Out?

When handled carefully, neodymium magnets preserve their magnetic strength for many decades. Being an alloyed material, they may show slight eroding as they age, but their core magnetic strength remains intact.

Subjecting Neodymium magnets to blunt forces may cause them to be demagnetized, which will trigger multiple negative implications both for the magnets and the gadgets or appliances on which they’ve been used. Corrosion can increase the possibility of demagnetization, especially as it affects the volume of the magnet. As with blunt forces, which alter the physical shape of the magnet, extended corrosion will equally reduce a magnet’s volume and, eventually, its magnetism. Care in handling and storing Neodymium magnets will prevent the occurrence of these.

Maintaining Magnets and Preventing Weakening

The most important way to preserve a magnet’s strength is to store it effectively:

  • Store magnets in pairs: Remember the golden rule of pole-pole interaction? Opposing poles attract, while like poles repel. Ensure that the same poles of different magnets aren’t placed parallel to each other; not doing this will make the fields repel and weaken the fields’ intensity. Likewise, the north poles should not touch the south poles. They may lie close to one another but should not be in contact.
  • Prevent corrosion: Corrosion is enabled by moisture in the environment, which allows oxygen to liberate and react with the magnet. Untreated corrosion will cause air gaps in the magnet, weakening the bond-bond connections in the structure of the magnets. The weaker its physical structure, the weaker its magnetic intensity. For specific applications in wet environments, purchase and use magnets manufactured as moisture-conducive and clean such magnets regularly.
  • Use a keeper. A keeper “keeps” your magnet’s north pole from interacting with the south pole. This prevents demagnetization by channeling the magnetic field lines along the right paths.
  • Package and ship magnets in non-ferromagnetic spaces. Keep your magnets in containers that won’t exert magnetic or electric forces. Wooden or hard cardboard boxes are great for storing multiple magnets. They will prevent spontaneous reactions and prevent magnets from drawing debris.
  • Keep from out-of-range temperatures. As discussed, temperature ranges impact a magnet’s behavior. In chemical reactions, the temperature is a key factor in speeding up or slowing down the rate of completion of reactions. Thus, many reactions are designed to be performed within specific ranges; taking these reactions outside of the assigned ranges will affect the results obtained. Likewise, extremely high or low temperatures will not leave a magnet similarly, affecting its magnetism.
  • Proper casing. Not in use? Case your magnets. Most magnets are shipped with accompanying rubber coatings. This serves multiple purposes: one, the coatings insulate the magnets from stray electric or magnetic fields; two, they prevent magnets from bumps due to transportation and movements; three, they keep the magnets from exposure to humidity. If a rubber coating wears out, do not hesitate to contact your magnet supplier for a replacement. This will keep your magnets from weakening or wearing out.

Restoring Magnetic Strength

Can a magnet’s strength be restored? Possibly. Magnets are multipurpose tools; different grades serve different functions and require varying degrees of strength. The magnet for sticking items to a refrigerator won’t share the same strength as the magnet in a plane’s magnetic compass. Certain magnet types, particularly of modest grades, can be made stronger by attempting the following:

  • Rubbing magnets against one another. Strong magnets can impart strength onto their weaker types. If you do this, ensure that your chosen magnets have their magnetic poles marked out so you don’t rub two similar poles against each other. Neodymium magnets are most suitable for this, given their high strength rating. Be careful when handling the magnets, though, as super strong neodymium magnets have harmful tendencies when treated with nonchalance.

Having marked the poles, preferably with color codes, proceed to rub the north end of the weakened magnet against the south end of the recharging magnet. Once done, repeat the process, alternating the poles (the south end of the weakened magnet against the north end of the recharging magnet). This would charge up the magnetic field of the weakened magnet and replace some of its lost strength.

  • Stacking magnets. There’s much strength in unity. This is true, too, for magnets. Piling magnets in a container or box will increase the overall strength of the magnets. When stacked, the magnets merge fields and work together as one big magnet, exerting a strong magnetic field. Stacking is quite tricky, though. Why? Magnets attract one another from opposite poles, and this reduces the strength they exert. To optimize combined fields, the magnets must be kept in an unnatural position (parallel and not opposite). Once done, the strength of magnets is boosted.

Conclusion

Neodymium magnets, and many others, are printed as permanent materials designed to function for decades and applications. Corrosion, temperature fluctuation, and improper storage can all be prevented by following the necessary preservation procedures highlighted in this article. If a magnet is properly manufactured, it will be in premium condition for years after it is shipped for use.

Should you observe reduced magnetic strengths? Observe precautionary steps that affect the strength of magnets. When not in use, keep magnets in conducive conditions. Replace casings when worn. Clean after use and store in a dry place.

 

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Article by

ROBO Magnetic Product Team

We are the manufacturer with 16 years of experience in custom neodymium magnets.

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