Choosing the Right Business Magnet, Based On Operating Temperature
When purchasing magnets for your business, one important consideration is the operating temperature. Temperature can impact magnetic strength significantly, especially if the operating temperature is extremely hot or cold.
When a magnet is in extreme temperatures, the balance between temperature and the magnetic domain (the atoms inside that spin in a particular direction) becomes destabilized, altering its magnetic properties.
Most magnets perform better in cold temperatures than hot, but each type of magnet is different. The magnet's reaction to temperature depends on the magnet material, size, and shape. If you don't consider these factors, you may have to replace magnets, which can be costly and dangerous.
Here’s what you should consider when selecting a type of permanent magnet:
Rare Earth Magnets
While neodymium magnets are strong, extreme temperatures can alter the behavior of their atoms. As a result, their overall strength may fluctuate while they’re in use, creating potential hazards. Extreme heat is detrimental for neodymium magnets—They will begin to lose their magnetic properties if heated above 176° F (82° C). If a neodymium magnet is not stored in this environment for a prolonged period of time, its magnetism can be fully restored. They also have a Curie temperature of about 320°C, which is where magnetism is completely lost. Note: If a customer needs the strength of a neodymium magnet in a hotter environment, there are higher ratings of magnets available that can withstand higher temperatures.
Neodymium magnets maintain their stability in cold temperatures–its magnetic structure only change in low temperatures at -138 degrees Celsius.
In general, a thin neodymium magnet will be more susceptible to heat than a thicker one. However, you can adjust heat resistance by altering the materials inside the magnet, such as introducing dysprosium and erbium in a custom magnet, which can sustain temperatures up to 200°C if using higher rated neodymium magnets.
Samarium Cobalt Magnets
Neodymium magnets are stronger than Samarium Cobalt magnets; however, Samarium Cobalt magnets perform better in extreme temperatures. They have a maximum operating temperature of about 350°C. and Curie temperatures range from 700 to 800°C.
Because they have good thermal stability, they work well in motors, automotives, and aerospace applications where high temperatures are prevalent. In colder temperatures, they can maintain their magnetic properties in temperatures as low as -273°C, making them ideal for colder applications.
Because ceramic magnets are brittle, they do not work well in extremely cold temperatures—They become fragile and often shatter, losing their strength completely. Compared to neodymium magnets, neodymium magnets have better strength stability than ceramic magnets.
Unlike most types of magnets, they are easier to demagnetize at low temperatures and harder to demagnetize at high temperatures. This makes them good in terms of value and performance in high-temperature applications. They have a maximum operating temperature of about 250°C and a Curie temperature of about 450°C. When in cold temperatures, they show permanent loss of strength when temperatures reach below -60°C.
Purchase Custom Magnets From Apex Magnets
If you need a specific magnet shape, size, and strength, you can purchase custom magnets. On the request form, you’ll be asked if the magnet will need to perform in a temperature higher than 176°F, and you can select “Yes,” “No,” or “Not sure/need advice.” You can also choose other specifications that influence a magnet’s reaction to temperature, including shape, thickness, and coating/finish.
If you have any questions while filling out your custom magnet request form, don’t hesitate to contact us.