How Long Do Magnets Last?

Magnets are essential in industries ranging from renewable energy to electronics, but how long do they last?

The sintered neodymium magnets, with which, theoretically, the magnetic force can be maintained permanently. According to a 12-year-long experiment conducted by Zhong Ke San Huan Research Institute: 8pcs un-coated NdFeB magnet samples (Hcj=1240kA/m, 10.2mm length) were put in the environment of 22°C~28°C with full exposure to air for continuous 12 years (more than 4441 days), shows that in the first 6 years, barely any magnetic loss can be found.

Based on this testing result, we conclude that less than 1% magnetic loss can be seen in 30 years(about 10950 days). NdFeB with surface treatment will have much better anti-oxidation features.

Reference: On page 289 of the first volume of Rare-earth Permanent Magnet Materials by Hu Boping, Rao Xiaolei, Wang Yizhong 2017.1. The "13th Five-Year Plan" National Key Publication Publishing Planning Project, ISBN 978-7-5024- 7435-5

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In actual applications, the lifetime of the magnets depends on several factors, including material type, environmental exposure, and external forces.

Neodymium magnets, known for their strength, typically lose less than 1% of their magnetic strength over 10 years under ideal conditions. However, exposure to high temperatures, corrosion, or strong opposing magnetic fields can reduce their lifespan. The demagnetization rate is slower for magnets like Alnico or ferrite, but environmental factors still play a significant role.

Factors That Impact Magnet Longevity:

Temperature: Exposure to heat above a magnet’s Curie temperature causes irreversible loss of magnetism. Neodymium magnets, for instance, start losing strength around 80°C.

Corrosion: Uncoated magnets, particularly neodymium magnets, are vulnerable to corrosion, which can degrade their performance over time.

External Fields: Strong external magnetic fields can partially demagnetize a magnet if oppositely aligned.

?Advantages of rubber-coated magnets

Rubber-coated magnets have several features that make them versatile and reliable for numerous applications. Here are the key characteristics:

1. Strong Magnetic Force Rubber-coated magnets typically use powerful neodymium magnets, offering high magnetic force. This strength enables them to hold or secure heavy objects with ease.
2. Protective Rubber Coating The rubber casing serves two functions:
3. Versatility Rubber-coated magnets are widely used in industrial environments, vehicles, signage, and home applications due to their adaptable design.
4. Weather Resistance The rubber coating provides resistance to weather conditions, allowing the magnets to be used outdoors in rain, snow, or extreme temperatures without losing their effectiveness.
5. Easy Installation and Removal These magnets are easy to install and remove without requiring tools, screws, or additional fasteners. This makes them highly convenient for temporary applications.

The combination of magnetic strength, durability, versatility, weather resistance, and ease of use makes rubber-coated magnets an excellent choice for many industries and applications.