Grades of Neodymium Magnet, which one is the best?

Confused by what all the different letters and number in a grade’s name mean? Here, we will explain the difference in grades of neodymium magnets.

We often heard people mention N52 Neodymium magnet, but what does the N52 really means.

The Neodymium magnets have simple nomenclature, which starts with “N”. It is the industrial simplification of Neodymium and then it is followed by two digit number

The two digit number represents the maximum energy product (BH), it is measured in Mega-Gauss Oersteds (MGOe), 1 MGOe = 7.958KJ/m3(SI UNITS). The number ranges from N24 up to N52. The lower grades are no longer made and the range now starts from N35. The highest is N52 and it is only available in certain size. N52 means that the Max energy product ranges between 50 and 53 MGOe.

There is also a suffix letter or two letters that follow the two digit number. These letter related to a temperature rating. Scientifically the letter indicate the Intrinsic Coercivity (Hci) of the material. The higher the Hci, the higher the temperature the Neodymium magnet material can be exposed to before the magnet will start to show permanent losses in output. Most people relate the letter to the working temperature of the magnet. For example, M means that the magnet can work well up to 100℃, H ~ up to 120℃ , SH ~ up to 140℃, UH~ up to 180℃, EH~ up to 200℃ and AH~up to 230℃

However, the temperature rating for Neodymium is merely a guide value. The physical size and shape of the NdFeB magnet and the working environment that actually determines how well a magnet will perform at raised temperature. For example a NdFeB magnet in free space will demagnetize at a lower temperature than the same sized NdFeB magnet connected to a piece of mild steel.

It is very important to understand the working environment temperature where the magnet is used and connected in the assembly. For example, if a magnet is part of an electric motor, one should know after the motor running for few hours, will the temperature increase and to what level. This will determine what type or grade of Neodymium magnet suitable for the application.

Below is a table showing different grade of Neodymium magnet and its related properties.

If you would like to get more details information or on how to select suitable type of magnet for your industrial use, feel free to contact us.