Which Neodymium Magnet Is the Strongest?
Magnets are one of the most amazing inventions in human history. If nothing at all, they are the first technology demonstrating levitation and telekinesis, i.e., the ability to move objects without touching them. Although magnets can only move metals and ferromagnetic alloys and materials, they will likely be scientists’ first stop when the time comes to develop a gadget that can help humans move objects without physical interaction.
Among magnets, however, neodymium magnets are the best on the market for virtually every application out there. Neo magnets are so popular that people who naturally have nothing to do with magnets make efforts to get a few for themselves. However, there are several neodymium magnet grades, each possessing a unique strength. In this article, we will help you identify which neodymium magnet happens to be the strongest overall and other related questions.
Which Neodymium Magnet Is the Overall Strongest?
The overall strongest neodymium magnet, all factors considered, is the N55. The “N55” is the highest neodymium magnet grade, meaning that it possesses the highest remanence levels, energy product, intrinsic coercivity, and temperature resistance. However, it is not commercially available yet. The strongest commercially available neodymium magnet is the N50 which has a maximum energy product of up to 51 MGOe. However, irrespective of the information on a neodymium magnet grades table, you can contact ROBO Magnetic with your requirements to help manufacture custom neo magnets for your application.
The Strength of Neodymium Magnets
Neodymium magnets are the strongest commercially available Neodymium magnets, no doubt. But just how strong are they in performance and comparison to other magnets? Magnets’ strengths are determined mainly by their holding force and magnetic flux density, i.e., the force of their magnetic fields measured in gauss or tesla. Neodymium magnets grades have unique magnetic flux densities, meaning that some neodymium magnets generate more powerful magnetic fields than others.
Also, some other magnets and materials generate magnetic fields. The earth itself generates a magnetic field which helps in the proper functioning of compasses. While earth’s magnetic flux is just five gausses at the surface, neodymium magnets can go as high as 14,300 gausses. Below is a list of different magnets and their magnetic flux.
- 14,600 Gauss– Neodymium (NdFeB) magnet (grade N50)
- 12,500 Gauss– Alnico (AlNiCo) magnet (grade 5)
- 11,000 Gauss– Samarium Cobalt (SmCo) magnet (grade 2:17)
- 3,700 Gauss– Ferrite magnet
- 100 Gauss– Standard refrigerator magnet
- 5 Gauss– Earth’s magnetic field at its surface
The strength of neodymium magnets is evident in their magnetic fields and holding force. How many loads can they hold or lift vertically or horizontally? Neodymium magnets are so strong that experts have speculated they can hold up to 1,300 times their weight. A 2kg neodymium magnet can hold about 2,600 kg. It is possible because of the sheer force generated by these magnets. They are so powerful that handling them requires so much care. Unlike several other magnet types, you cannot hold two neodymium magnets close to one another. They would slam into each other with so much force that they would shatter, and tiny pieces may fly around, causing injuries.
Grades of Neodymium Magnet
Neodymium magnets are not made the same. Some generate more powerful magnetic fields than others, and some have higher heat resistance than others. This distinction is indicated in the different grades of these neodymium magnets, up to nine. Neodymium magnets have nine primary grades. Then each grade has variants that have increased performance. These variants are indicated by a letter after the grade number.
For example, the ordinary neodymium magnet has N as the grade. They are the primary neodymium magnets that can withstand high temperatures up to 80°C without experiencing any loss of magnetism. We have nine neodymium magnets on this level, and their differences are in their magnetic strength. The N30 magnet has 10.8 and 11.2 kilogauss, i.e., 10,800 and 11,200 Gauses. Consider the table below.
||10.8 – 11.2
||1.08 – 1.12
||11.4 – 11.7
||1.14 – 1.17
||11.7 – 12.1
||1.17 – 1.21
||12.2 – 11.6
||1.22 – 1.16
||12.6 – 12.9
||1.26 – 1.29
||13 – 13.3
||1.3 – 1.33
||13.3 – 13.7
||1.33 – 1.37
||13.7 – 14
||1.37 – 1.4
||14 – 14.6
||1.4 – 1.46
The variants of these neodymium magnets can withstand higher temperatures than the basic ones. The primary grades have a max operating temperature of 80°C and a curie temperature of 310°C, but the variants can withstand more heat. A letter or two is attached to the grade number to indicate variants. For instance, a magnet with the letter M after it will have an operating temperature of 100°C, while one with the letter UH can withstand up to 180°C. The table below shows all the variants of neodymium magnets and how much heat they can resist.
||Max Operating Temperature
||80°C or 176°F
||310°C or 590°F
||100°C or 212°F
||340°C or 644°F
||120°C or 248°F
||340°C or 644°F
||150°C or 302°F
||340°C or 644°F
||180°C or 356°F
||350°C or 662°F
||200°C or 3922°F
||350°C or 662°F
Neodymium Magnet With the Highest Max Energy Product
The commercially available neodymium magnet with the highest max energy product (BHmax) is the N50 grade. It is noteworthy that neodymium magnets are graded by their BHmax value, and the number following the N is usually the magnet’s BHmax in mega gauss oersted (MGOe). Hence, an N30 neodymium magnet has a max energy product of 30 mega gauss oersted. Thanks to our advanced manufacturing process at ROBO Magnetic, our strongest magnet, the N50, has a maximum energy product of 51 mega gauss oersted.
The maximum energy product is an important figure measuring a magnet’s capacity. It refers to the amount of energy or magnetic strength stored permanently in the magnet. Bhmax depends on size; you can pick a small magnet with high BHmax or a large magnet with low BHmax to reach the desired magnetic flux.
Neodymium Magnet With the Strongest Magnetic Field
The neodymium magnet with the strongest magnetic field is also the one with the highest grade.
The higher the grade, the stronger the magnetic field. So, generally, a single N50 neodymium magnet will generate a stronger magnetic field than an N30 magnet. It is believed that this value is not independent of size. That is, a large magnet of a particular grade will generate more powerful magnetic fields than a small magnet of the same grade. It is normal because the larger magnet has more surface area and magnetic domains than the smaller one. So, even though they are of the same grade, one is stronger than the other because of its size.
Neodymium Magnet With the Highest Residual Flux (Remanence)
Again, the neodymium magnets with the highest residual flux, or remanence, is the one with the highest grade: currently the N50. As a rule, in neodymium magnet production, the higher the grade, the higher the capacity.
The residual flux density refers to how much energy is retained in a magnet after it has been magnetized. After a magnet has been made into the desired shape, the last step is to expose it to a magnetizing field to become magnetized. When it is magnetized, it can then generate its own magnetic field. However, not every material has the capacity to retain magnetism like the others. Generally, high remanence is preferred. The residual flux density of a neodymium magnet is affected only by the grade, not by the size.
Neodymium Magnet With the Highest Coercivity Rating
The coercive force for all neodymium magnets is within the same range: 10.5 to 11.5, with the N30 and N35 having the highest ratings. On the other hand, the intrinsic coercive force for all neodymium magnets is the same for all grades. However, even though they have the same intrinsic coercive force, the value increases for each variant set of neodymium magnets. For instance, all neodymium magnets with the letter M have an intrinsic coercive force value of ≥1114, those with the letter H have ≥1353, and so on.
The coercive force is a bit different from the intrinsic coercive force.
The coercive force refers to the strength of the external field required to demagnetize a magnet and bring the residual flux density to zero. At this point, the magnet loses magnetism, but it can be re-magnetized. On the other hand, intrinsic coercive force refers to the magnetic force required to cause a permanent loss of magnetism in a magnet. When a magnet is exposed to an opposing magnetic force of this value, it losses magnetism permanently and cannot be re-magnetized.
Neodymium Magnet With the Highest Temperature Resistance
Like the coercive force, all neodymium magnet grades have the same temperature resistance across all grades, with differences only in the variant sets. The set of neodymium magnets that have the highest temperature resistance is those that have the letter EH after the grade number. These neodymium magnets have a working temperature of up to 200°C and a curie temperature of up to 310°C.
The overall strongest neodymium magnet is the one with the highest grade. However, it does not mean it is the best one for your assembly. Depending on your magnet’s function, you may need to prioritize certain qualities over sheer strength.
For instance, in an assembly where your magnet will be exposed to high temperature, you need a magnet with high coercivity; that is why there are different grades and variants of neodymium magnets.