Grade of Neodymium Magnets:
Neodymium magnets come in different grades such as N42, N52 or N42SH.
It all starts with the letter ‘N’, all the names of neodymium magnets begin with ‘N’ for neodymium. The number that follows is a little more technical as this represents the maximum energy product of the magnet in ‘Mega-Gauss Oersteds’ (MGOe). This is the primary indicator of a magnets ‘strength’. In general, higher numbers indicate a stronger magnet.
According to strength of coercive force of sintered neodymium permanent magnet products, products can be classified into different types:
normal coercive force (N), medium coercive force (M), high coercive force (H), super high coercive force (SH), ultra high coercive force (UH), extremely high coercive force (EH) and advanced high (AH).
| Type | Grade | Residual Induction /BR(Gauss) | Coercive Force/Hc (Oe) | Intrinsic Coercive Force/Hci (Koe) | Max.Energy Product/Bhmax (MGOe) | Maximum Operating Temp (°C/°F) | Curie Temp (°C/°F) |
| N | N35 | 11700 | 10900 | 12 | 35 | 80/176 | 310/590 |
| N | N38 | 12200 | 11300 | 12 | 38 | 80/176 | 310/590 |
| N | N40 | 12500 | 11400 | 12 | 40 | 80/176 | 310/590 |
| N | N42 | 12800 | 11500 | 12 | 42 | 80/176 | 310/590 |
| N | N45 | 13200 | 11600 | 12 | 45 | 80/176 | 310/590 |
| N | N48 | 13800 | 11600 | 12 | 48 | 80/176 | 310/590 |
| N | N50 | 14000 | 10000 | 11 | 50 | 60/140 | 310/590 |
| N | N52 | 14300 | 10000 | 11 | 52 | 60/140 | 310/590 |
| M | N33M | 11300 | 10500 | 14 | 33 | 100/212 | 340/644 |
| M | N35M | 11700 | 10900 | 14 | 35 | 100/212 | 340/644 |
| M | N38M | 12200 | 11300 | 14 | 38 | 100/212 | 340/644 |
| M | N40M | 12500 | 11600 | 14 | 40 | 100/212 | 340/644 |
| M | N42M | 12800 | 12000 | 14 | 42 | 100/212 | 340/644 |
| M | N45M | 13200 | 12500 | 14 | 45 | 100/212 | 340/644 |
| M | N48M | 13600 | 12900 | 14 | 48 | 100/212 | 340/644 |
| M | N50M | 14000 | 13000 | 14 | 50 | 100/212 | 340/644 |
| H | N35H | 11700 | 10900 | 17 | 35 | 120/248 | 340/644 |
| H | N38H | 12200 | 11300 | 17 | 38 | 120/248 | 340/644 |
| H | N40H | 12500 | 11600 | 17 | 40 | 120/248 | 340/644 |
| H | N42H | 12800 | 12000 | 17 | 42 | 120/248 | 340/644 |
| H | N45H | 13200 | 12100 | 17 | 45 | 120/248 | 340/644 |
| H | N48H | 13700 | 12500 | 17 | 48 | 120/248 | 340/644 |
| SH | N35SH | 11700 | 11000 | 20 | 35 | 150/302 | 340/644 |
| SH | N38SH | 12200 | 11400 | 20 | 38 | 150/302 | 340/644 |
| SH | N40SH | 12500 | 11800 | 20 | 40 | 150/302 | 340/644 |
| SH | N42SH | 12800 | 12400 | 20 | 42 | 150/302 | 340/644 |
| SH | N45SH | 13200 | 12600 | 20 | 45 | 150/302 | 340/644 |
| UH | N28UH | 10200 | 9600 | 25 | 28 | 180/356 | 350/662 |
| UH | N30UH | 10800 | 10200 | 25 | 30 | 180/356 | 350/662 |
| UH | N33UH | 11300 | 10700 | 25 | 33 | 180/356 | 350/662 |
| UH | N35UH | 11800 | 10800 | 25 | 35 | 180/356 | 350/662 |
| UH | N38UH | 12200 | 11000 | 25 | 38 | 180/356 | 350/662 |
| UH | N40UH | 12500 | 11300 | 25 | 40 | 180/356 | 350/662 |
| UH | N42UH | 12800 | 11300 | 25 | 42 | 180/356 | 350/662 |
| EH | N28EH | 10400 | 9800 | 30 | 28 | 200/392 | 350/662 |
| EH | N30EH | 10800 | 10200 | 30 | 30 | 200/392 | 350/662 |
| EH | N33EH | 11300 | 10500 | 30 | 33 | 200/392 | 350/662 |
| EH | N35EH | 11700 | 11000 | 30 | 35 | 200/392 | 350/662 |
| EH | N38EH | 12200 | 11300 | 30 | 38 | 200/392 | 350/662 |
| EH | N40EH | 12500 | 11300 | 30 | 40 | 200/392 | 350/662 |
| AH | N28AH | 10400 | 9900 | 33 | 28 | 230/446 | 350/662 |
| AH | N30AH | 10800 | 10300 | 33 | 30 | 230/446 | 350/662 |
| AH | N33AH | 11300 | 10600 | 33 | 33 | 230/446 | 350/662 |
| AH | N35AH | 11700 | 11000 | 33 | 35 | 230/446 | 350/662 |
| AH | N38AH | 12200 | 11300 | 33 | 38 | 230/446 | 350/662 |
1. Residual Induction /BR(Gauss)
Residual Induction (Br) is the magnetic flux density that a magnetic material retains after being magnetized to saturation and removing the external magnetic field. In simple terms, the higher the remanence, the stronger the magnetic field generated by the material.
2. Coercive Force/Hc (Oe)
Coercivity (Hc) is the magnitude of the reverse magnetic field required to reduce the magnetic flux density of a magnetized material to zero. The higher the coercivity, the greater the material’s resistance to demagnetization.
3. Intrinsic Coercive Force/Hci (Koe)
Intrinsic Coercivity (Hci) is the magnitude of the reverse magnetic field required to reduce the magnetization inside a magnetic material to zero. A higher intrinsic coercivity indicates greater resistance to complete demagnetization.
4. Max.Energy Product/Bhmax (MGOe)
The Maximum Energy Product (BHmax) represents the maximum magnetic energy stored per unit volume of a magnetic material and is a key performance indicator. The higher the value, the better the magnetic properties of the material.
5. Maximum Operating Temp (°C/°F)
Maximum Operating Temperature is the highest temperature a magnetic material can withstand without irreversible demagnetization. Different materials have varying maximum operating temperatures. For example, standard-grade NdFeB magnets can operate up to 80°C, while high-temperature grades (e.g., SH) can reach 150°C.
6. Curie Temp (°C/°F)
Curie Temperature is the critical temperature at which a magnetic material transitions from ferromagnetic to paramagnetic. When the temperature exceeds the Curie Temp, the material loses its magnetic properties entirely.
How to choose different grades of NdFeB magnet products?
Choose the right grade for your application
The magnetic strength required varies greatly from one application scenario to another. For example, in equipment that requires a strong magnetic field, such as motors and generators, choosing a high-grade NdFeB magnet (e.g., N45, N52, etc.) can provide a higher magnetic output, which can significantly improve the performance and efficiency of the equipment. These high grade magnets are capable of generating stronger magnetic fields and are suitable for professional equipment with extremely high magnetic requirements.
For applications with relatively low magnetic force requirements, such as small electronic devices and toys, medium grade magnets (e.g. N35, N42, etc.) are sufficient. These mid-grade magnets are not only stable, but also cost-effective, providing a cost-effective solution for your project.
Focus on the temperature of the working environment
The temperature of the working environment is an important factor that should not be ignored when choosing the grade of NdFeB magnets. If the equipment needs to operate in a high temperature environment, such as an industrial furnace, automotive engine, etc., then choosing magnets with higher operating temperature grades (such as SH, UH or EH grades) is necessary. These high-temperature grade magnets are able to maintain stable magnetic properties under harsh high-temperature conditions, effectively avoiding demagnetisation or damage to the magnet caused by high temperatures, and ensuring the long-term reliable operation of the equipment.
On the other hand, if the equipment is mainly operated in room temperature environment, choosing the standard working temperature grade of magnets (such as N grade) can meet the requirements of use. This not only meets the magnetic requirements of the equipment, but also helps you reduce costs and utilise resources wisely.
Consider magnet size and weight limitations
In applications where space and portability are critical, magnet size and weight become a key factor. For example, in aerospace or portable electronic devices, the design of the equipment often places strict limits on the size and weight of components. In such cases, the selection of high-grade NdFeB magnets can provide the required magnetic force in a smaller size and weight to meet the compactness and lightweight requirements of the equipment. These high-performance magnets are ideal for high-tech equipment as they are able to maximise the magnetic effect in a limited space.
And if size and weight are not strictly limited, mid-range magnets may be a more cost-effective option. They can fulfil basic magnetic requirements while providing you with a more cost-effective solution for a wide range of conventional equipment and applications.
Higher grades of NdFeB magnets typically offer superior magnetic performance, but they are also relatively expensive. Therefore, when choosing a magnet grade, a balance between cost and performance needs to be considered.
Selecting different grades of NdFeB magnet products requires a combination of factors, including magnetic strength, operating temperature, size and weight constraints, and the balance between cost and performance.