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Questions and answers about the grade of magnets

The specifications N40, N42, N45, 35H etc. is a measurement for the quality of the magnet material. This tells you two things:
  1. Up to what temperature the magnet can be used
  2. How much "magnetic energy" per volume is contained in this magnet material

Table of Contents

What do the specifications N42, N45, N50, etc., mean?

The letters N, M, H, SH, UH or EH indicate the maximum working temperature of a magnet. Most of our magnets begin with the letter 'N' and can thus withstand temperatures of up to 80 °C. You can find out which letter corresponds to which maximum working temperature under FAQ "What temperatures can magnets withstand?". You will also find information on the maximum operating temperature listed under the technical data section on the product pages for our magnets.
The numbers (e.g., 40, 42, 45) correspond approximately to the maximum energy product of the magnet in MGOe (Mega Gauss Oersted). It is an indicator of magnet strength – the higher the number, the stronger the magnet. According to the current state of the art, grade 52 equates approximately to the largest possible maximum energy product of a permanent magnet. The number 33, in turn, is equivalent to the smallest possible energy product that we carry in our online shop. This number classification system is not used to assess quality but is based solely on magnetic properties.
You can find the exact correlations between these classifications and the physical values of a magnet in the table Physical Magnet Data.

Magnetisation vs. Size

If you take any two magnets of different sizes and magnetisation from our assortment, the difference in their strength is based more on the differences in their volume than the differences in their magnetisation. That's why the larger magnet is usually the stronger magnet, even if its magnetisation classification is somewhat smaller.
Here is an example: The neodymium disc magnet S-30-10-N has a diameter of 30 mm and a height of 10 mm, featuring an N45 magnetisation and an adhesive force of 20 kg. Let’s compare it with the neodymium disc magnet S-30-15-N. The latter is slightly bigger with a diameter of 30 mm and a height of 15 mm. Despite a lower N42 magnetisation, its adhesive force is higher, namely 24 kg. This example shows that magnetisation alone is not conclusive.

Which magnetisation should I choose?

That depends on what is required of the magnet. Basically, the following applies: the higher the magnetisation grade number, the more magnetised the magnet is.
  • If the magnet should be as strong as possible, even at a small size, then we recommend N52 neodymium magnets. Keep in mind that magnets with an N52 grade can only be used at temperatures of up to about 65 °C.
  • A particularly large selection of magnets with different strengths and shapes can be found among N45 magnets and N42 magnets.
  • If the magnet needs to withstand temperatures above 80 °C, we recommend neodymium magnets for high temperatures.
Many of our customers do not select magnets primarily based on the grade but according to criteria such as adhesive force and shape. That’s why we would also like to direct you to the summary page for our neodymium magnets. Under the linked shop categories, you can filter magnets by adhesive force, dimensions and specific characteristics.
The summary table for neodymium magnets also gives you an overview of all our super magnets. Here, key figures regarding adhesive force, coating, maximum temperature and so on are given for each magnet. You can sort the columns in ascending or descending order, allowing you to quickly determine which magnets in our assortment meet your requirements.

Neodymium magnets sorted by magnetisation

Are you looking for a neodymium magnet with a specific grade? Below you can find all neodymium magnets in our assortment grouped by magnetisation: