Almost everything has a shelf life. Certainly most food products at the grocery store will “go bad” if you don’t eat them before a certain date, but other products—including electronics, furniture, and even magnets—will weaken, become unsafe, or lose their ability to function as intended if not stored in a standardized setting or used within a certain number of years. If you want to limit damage to your magnets and prolong their shelf life, consider the following factors: net magnetic field strength, proper packaging, and safe storage.

Net Magnetic Strength and Demagnetization

It’s unclear whether or not magnets will lose strength or durability if simply left untouched in a stable temperature. However, if there is deterioration in net magnetic field strength, it is likely due to natural demagnetization, which happens over an extended period of time. Unused magnets typically don’t demagnetize at a noticeable rate, but their strength can still deteriorate over several years – usually five to ten. In storage, permanent and rare earth magnets can attract other magnetic fields that weaken their own magnetic fields. When different types of magnets are stored together, they have the potential to interact. Alnico and ceramic magnets are more prone to this. When packing multiple magnets of the same type, be sure the poles alternate and attract each other, meaning their north poles face opposite directions. If you have magnets with a strong hold, like neodymium, use a keeper bar or magnetic shielding as a powerful magnet can potentially demagnetize a weaker one. Other external elements – such as volume loss (due to chipping or corrosion) and temperature change – may have a more immediate effect on your magnets’ strength.

Packaging and Storage: Volume Loss and Temperature

If your magnets are being packaged, handled, and stored, there will likely be unavoidable degradation – chips, scratches, etc. However, if you use caution, you can limit volume loss, which results from corrosion over time. Be sure to store magnets in a clean and dry environment. Neodymium magnets, for example, are likely to suffer from moisture degradation if not stored in a dry area. Also, as mentioned above, you should store your magnets with spacers or separations. Dropping your magnets, hitting them with extreme force, or applying extreme pressure can weaken or demagnetize them as well. Excessive heat can also directly impact permanent and rare earth magnets by causing corrosion and weakening the magnetic fields. Most warehouses don’t reach a high enough temperature to cause damage, but leaving a magnet outside on a hot summer day would potentially weaken or demagnetize it.

Tolerance Breakdown

Here’s a breakdown of the susceptibility-to-damage rate of the most common types of magnets. The frequencies are distinguished by high, medium, and low.
Magnet Chipping Corrosion External Fields
Samarium Cobalt High Low Very Low
Ceramic (Strontium Ferrite) Low Medium Medium
Neodymium Medium High Low
Alnico Medium Very Low Medium

Use Apex Magnets Today

At Apex, our stock magnets are handled, stored, and cared for to avoid damage and expand shelf life. To learn more about the proper way to pack and store, check out our basic guide. If you need further guidance on what might impact a magnet’s strength and durability, or if you would prefer to order custom magnets for your business, visit our request form.