Magnet grade, as an abbreviation for quickly identifying magnet performance in the industry, is the basic knowledge that practitioners in the magnetic industry must master. There may be some cross-industry buyers or purchasers who are new to magnets who are not very clear about the concept of magnet grades. In order to help everyone clear up their doubts, Osencmag will explain the grade classification of neodymium magnets and the corresponding key magnetic properties, physical properties and temperature resistance at once. Follow me, I believe you will definitely gain something.
What is Magnet Grade?
Magnet grade refers to a numerical value that represents the strength and performance of a magnet. It is a measure of the maximum energy product (BHmax), which is the point of highest magnetic strength on a magnet’s demagnetization curve, expressed in MGOe (Mega Gauss Oersteds). Simply put, the higher the number in the magnet grade, the stronger the magnet.
For example, a magnet grade like N52 refers to a Neodymium magnet with a maximum energy product of 52 MGOe, making it one of the strongest types of permanent magnets available. On the other hand, an N35 magnet would be relatively weaker.
Magnet grades often consist of a letter followed by a number:
- N stands for Neodymium (a type of strong rare-earth magnet).
- C denotes Ceramic.
- SmCo represents Samarium Cobalt.
The number represents the magnet’s strength (measured in MGOe). Higher numbers indicate stronger magnets. The most common grades of Neodymium magnets are N35, N38, N40, N42, N45, N48, N50, N52, and N55.
The letter S or SH in a grade like N42-SH provides additional details regarding the magnet’s temperature resistance, indicating how well the magnet can withstand heat before it begins to lose its magnetism. For instance, N42 refers to a magnet with a maximum energy product of 42 MGOe, while SH signifies its ability to withstand higher temperatures.
Taking Samarium Cobalt (SmCo) magnets as an example again, the BHmax range is from 16 MGOe to 32 MGOe. Its grade writing format is the same as neodymium magnets, and the higher the number after “SmCo”, the stronger the magnetic force. Common grades of samarium cobalt magnets are SmCo16, 18, 20, 22, 24, 26, 28, 30 and 32. As you can see, neodymium magnets have a higher MGOe value than samarium cobalt magnets, which indicates that the maximum magnetic energy product of neodymium magnets is stronger than that of samarium cobalt magnets.
Different types of magnets, such as Neodymium, Samarium Cobalt, Alnico, and Ferrite, have varying strength ranges, with Neodymium being the strongest, followed by Samarium Cobalt, Alnico, and Ferrite. The grade of the magnet you choose should depend on the specific requirements of your application, such as strength needs and temperature tolerance.
Check out the differences between the two most common commercial magnets (neodymium magnets and ferrite magnets).
| Raw Magnetic Material | Grade Ranges (MGOe) |
|---|---|
| Alnico/Alnico Sintered | 2-8 |
| Ceramic | 1-8 |
| High Energy Flexible | 1.1, 1.4, 1.6 |
| Neodymium | 30-54 |
| Bonded Neodymium | 10 |
| Samarium Cobalt | 18-30 |
Regular Neodymium Magnet Grades.
Neodymium magnets, also known as NdFeB magnets, are commonly graded by their maximum energy product, which is represented by a number following the letter “N.” This number, typically ranging from N35 to N55, indicates the strength of the magnet, with higher numbers denoting stronger magnets.
Here are some common grades of Neodymium magnets:
The number after the “N” represents the Maximum Energy Product (BHmax) of the magnet, measured in MGOe (Mega Gauss Oersteds). For instance, an N35 magnet has a maximum energy product of 35 MGOe, while an N52 magnet has a maximum energy product of 52 MGOe, making it one of the strongest available grades.
| Grade | Br (KGs) | Br (T) | Hcb (KOe) | Hcb (KA/m) | Hcj (KOe) | Hcj (KA/m) | (BH)max (MGOe) | (BH)max (KA/m³) | Max. Operating Temp (°C) |
|---|---|---|---|---|---|---|---|---|---|
| N35 | 11.7-12.2 | 1.17-1.22 | 10.8-11.5 | 860-915 | ≥12 | ≥955 | 33-36 | 263-287 | 80 |
| N38 | 12.2-12.6 | 1.22-1.26 | 11.0-11.7 | 875-930 | ≥12 | ≥955 | 36-39 | 287-311 | 80 |
| N40 | 12.6-13.0 | 1.26-1.30 | 11.2-11.9 | 890-950 | ≥12 | ≥955 | 38-41 | 302-326 | 80 |
| N42 | 13.0-13.3 | 1.30-1.33 | 11.3-12.0 | 900-955 | ≥12 | ≥955 | 40-43 | 318-342 | 80 |
| N45 | 13.3-13.7 | 1.33-1.37 | 11.4-12.1 | 910-965 | ≥12 | ≥955 | 43-46 | 342-366 | 80 |
| N48 | 13.7-14.1 | 1.37-1.41 | 11.5-12.2 | 915-970 | ≥12 | ≥955 | 46-49 | 366-390 | 80 |
| N50 | 14.1-14.5 | 1.41-1.45 | 11.6-12.3 | 920-975 | ≥12 | ≥955 | 48-51 | 382-406 | 80 |
| N52 | 14.5-14.8 | 1.45-1.48 | 11.7-12.4 | 930-990 | ≥12 | ≥955 | 50-53 | 398-422 | 80 |
| N54 | 14.8-15.2 | 1.48-1.52 | 11.8-12.5 | 940-995 | ≥12 | ≥955 | 52-55 | 414-438 | 80 |
Additionally, the presence of a letter after the grade, such as SH or H, indicates the temperature rating of the magnet, with higher letters signifying better heat resistance. If no letter follows the number, the magnet is considered to be of standard temperature rating. Are you interested in the different temperature resistance levels of neodymium magnets? Don’t worry, keep reading.
NdFeB Magnet Series with Different Temperature Grades
Neodymium Iron Boron (NdFeB) magnets are the strongest rare-earth magnets available, but their performance is heavily influenced by temperature. To address the varying temperature requirements in different applications, NdFeB magnets are produced in multiple grades, each with a specific maximum operating temperature. Below is a detailed and professional explanation of the various NdFeB magnet series, organized by temperature grade:
- Standard Grades (Nxx)
Working temperature: ≤80°C
Standard grades, such as N35, N42, and N52, are the most commonly used NdFeB magnets. These magnets provide the highest magnetic strength at room temperature but are limited in their thermal resistance.
Ideal for applications where the environment does not exceed +80°C, such as consumer electronics, sensors, and general-purpose devices. However, significant weakening may occur if exposed to temperatures above this range. - M Series (NxxM)
Working temperature: ≤100°C
The M series magnets are designed with improved heat resistance compared to standard grades. They maintain better magnetic performance at higher temperatures without noticeable degradation.
Suitable for slightly elevated temperature environments, such as robotics, small electric motors, or moderate industrial applications. - H Series (NxxH)
Working temperature: ≤120°C
H series magnets provide a balance between strong magnetic properties and moderate thermal resistance. The addition of specific materials during manufacturing enhances their ability to withstand higher temperatures.
Commonly used in industrial settings, such as automotive components, medical devices, and power tools, where temperatures may consistently rise to around 120°C. - SH Series (NxxSH)
Working temperature: ≤150°C
SH series magnets are specifically engineered for applications requiring higher temperature tolerances. While their magnetic strength may start to decline at elevated temperatures, they remain stronger than SmCo magnets up to +150°C.
Widely used in high-performance environments, such as advanced electric motors, wind turbines, and aerospace applications. - UH Series (NxxUH)
Working temperature: ≤180°C
UH series magnets are designed for demanding applications where high temperatures are a consistent challenge. They offer excellent resistance to thermal demagnetization.
Suitable for industrial machinery, automotive systems, and specialized motors operating in environments with sustained high temperatures. - EH Series (NxxEH)
Working temperature: ≤200°C
EH series magnets exhibit superior thermal stability, allowing them to operate in extreme environments with minimal risk of irreversible demagnetization. These magnets are engineered for high-temperature endurance while maintaining strong magnetic properties.
Used in high-temperature industrial and automotive applications, such as turbochargers, electric vehicle motors, and specialized sensors. - AH Series (NxxAH or NxxVH)
Working temperature: ≤230°C
The AH (or VH) series represents the pinnacle of NdFeB magnet temperature resistance. They are designed for extreme conditions where both high temperature and magnetic strength are critical. However, their magnetic strength is generally lower compared to standard grades at room temperature.
Found in cutting-edge technologies, including aerospace systems, high-temperature electronics, and heavy-duty industrial machinery where operating temperatures exceed +200°C.
A neodymium magnets strength with no letter after the grade, i.e. N38, or N45, or N52, would indicate that it has the ability to work in an environment that has a maximum operating temperature no greater than 80℃. A magnet with an “M” (i.e. N35M, N42M, etc.) generally means that a magnet can be used in an operating environment up to 100℃. An “H” material is good up to 120℃, “SH” up to 150℃, “UH” up to 180℃, “EH” up to 200℃, and a “TH” up to 230℃.
Key Considerations for Temperature Performance.
- Magnetic Strength vs. Temperature:
NdFeB magnets exhibit a reversible loss of magnetic performance as temperature increases, governed by the temperature coefficient of remanence (Br) and intrinsic coercivity (Hci). For most grades:
Br Coefficient (a): ~-0.12%/°C
Hci Coefficient (b): ~-0.6%/°C
For example, a rise of 20°C above ambient (~25°C) in an N42 magnet may result in a 2.4% drop in magnetic output due to reversible losses. This loss is recovered when the temperature returns to ambient. - Irreversible Loss:
If the temperature exceeds the magnet’s maximum operating range, an irreversible but recoverable loss may occur, where the magnet’s output does not fully return after cooling. This is due to partial demagnetization. In such cases, re-magnetization may be possible, but the magnet will demagnetize again if used in the same conditions. - Low-Temperature Effects:
NdFeB magnets can also operate at extremely low temperatures, but at ~135 Kelvin (-138°C), a phenomenon known as spin reorientation occurs, where magnetization shifts from an “easy-axis” to an “easy-cone.” This can cause a drop in output of up to 15%. Proper design considerations are needed for extreme low-temperature applications.
| NdFeB Material | Max Operating Temp | Curie Temp | ||
|---|---|---|---|---|
| Grade | ºF | ºC | ºF | ºC |
| N | 176 | 80 | 590 | 310 |
| M | 212 | 100 | 644 | 340 |
| H | 248 | 120 | 644 | 340 |
| SH | 302 | 150 | 644 | 340 |
| UH | 356 | 180 | 662 | 350 |
| EH | 392 | 200 | 662 | 350 |
| AH | 446 | 230 | 662 | 350 |
NdFeB magnets are stronger than samarium cobalt (SmCo) magnets at temperatures below 150°C.At higher temperatures (+150°C and above), SmCo magnets outperform NdFeB magnets, with maximum operating temperatures of +300°C to +350°C. SmCo is preferred for ultra-high-temperature environments, while NdFeB is better for applications requiring maximum magnetic strength at moderate temperatures.
By understanding the different temperature grades of NdFeB magnets and their associated performance characteristics, engineers can make informed decisions to optimize magnetic performance for specific applications. Always consider the full magnetic circuit and environmental conditions to avoid irreversible losses.
What are the key magnetic properties of NdFeB magnets?
Neodymium Iron Boron (NdFeB) magnets are known for their exceptional magnetic performance, making them widely used in various industrial and commercial applications. Their key magnetic properties include the following–
- Remanence (Br): Represents the residual magnetic flux density remaining in the magnet after being magnetized to saturation.
- Coercivity (Hcb): The resistance of the magnet to demagnetization in a closed circuit.
- Intrinsic Coercivity (Hcj): A measure of the magnet’s resistance to irreversible demagnetization, crucial for stability in high-temperature environments.
- Maximum Energy Product (BHmax): Indicates the maximum magnetic energy density stored in the magnet, influencing its efficiency in applications.
- Br Temperature Coefficient (αBr): Defines the rate at which remanence decreases with temperature, typically around -0.09% to -0.12% per °C.
- Hcj Temperature Coefficient (βHcj): Describes the variation of intrinsic coercivity with temperature, generally between -0.38% to -0.8% per °C.
- Operating Temperature: Standard NdFeB magnets can operate up to 80–230°C, depending on the Temperature resistance grade. High-coercivity variants can withstand even higher temperatures before significant magnetic degradation occurs.
These properties make NdFeB magnets the strongest commercially available permanent magnets, though their performance is highly dependent on temperature conditions and material grade.
| Property | Symbol | Unit | Typical Range |
|---|---|---|---|
| Remanence | Br | T (Tesla) | 1.17 – 1.5 |
| Coercivity | Hcb | kA/m | 868 – 1,145 |
| Intrinsic Coercivity | Hcj | kA/m | 955 – 2,624+ |
| Maximum Energy Product | (BH)max | kJ/m³ | 200 – 450 |
| Br Temperature Coefficient | αBr | %/°C | -0.09 to -0.12 |
| Hcj Temperature Coefficient | βHcj | %/°C | -0.38 to -0.8 |
| Operating Temperature— | – | °C | 80 – 230 (varies by grade) |
There are two points that require special attention for the magnetic properties of daily commercialized neodymium: magnet strength and intrinsic coercive force.
The strength of a magnet is the maximum energy density of the magnet (BHmax). This is defined in units of Mega-Gauss-Oersteds, or MGOe. On the magnetic demagnetization curve, this is the highest point of magnet strength.
The intrinsic coercivity is the “Hci” of the material. When you look at the magnet chart for available materials, some grades will have different letters after them. These letters represent the magnet’s ability to resist demagnetizing forces, which may be temperature or other opposing magnetic forces acting on the magnet. There are several ways in which manufacturers or suppliers define coercivity in the world of permanent magnets, but we will focus on the most widely used one, the alphabetic system. This lettering system uses the following letters after the grade to define magnet specifications for resistance to demagnetizing forces: M, H, SH, UH, EH and AH. Yes, that’s right. This is the letter system that represents the temperature resistance grade of neodymium magnets. For ease of understanding, we will use ambient heat as the demagnetization force because it is the most common force that affects magnets. When a letter is used after a neodymium magnet grade, it indicates that that particular material has a greater ability to resist demagnetizing forces.
High-Temperature Neodymium Magnet Specifications Table.
The standard conventional neodymium magnet grades have been sorted out above and will not be repeated here. Below is a comprehensive high-temperature neodymium magnet grade specification table.
| Grade | Max Energy Product (MGOe) | Residual Induction (Br) | Coercive Force (Hc) | Intrinsic Coercive Force (Hci) | Max Operating Temperature |
|---|---|---|---|---|---|
| N33M | 30-33 | 1.12-1.16 T | ≥836 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N35M | 33-36 | 1.17-1.20 T | ≥868 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N38M | 36-38 | 1.21-1.25 T | ≥899 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N40M | 38-41 | 1.25-1.28 T | ≥923 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N42M | 42-44 | 1.28-1.32 T | ≥955 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N45M | 43-46 | 1.32-1.38 T | ≥995 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N48M | 45-49 | 1.37-1.43 T | ≥1027 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N50M | 47-51 | 1.40-1.45 T | ≥1033 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N52M | 50-53 | 1.42-1.46 T | ≥1043 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N54M | 51-55 | 1.45-1.49 T | ≥1051 kA/m | ≥1114 kA/m | 100°C (212°F) |
| N33H | 33-35 | 1.12-1.16 T | ≥836 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N35H | 33-35 | 1.17-1.22 T | ≥868 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N38H | 36-39 | 1.22-1.25 T | ≥899 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N40H | 38-41 | 1.25-1.28 T | ≥923 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N42H | 40-43 | 1.28-1.32 T | ≥955 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N45H | 40-43 | 1.32-1.37 T | ≥955 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N48H | 43-436 | 1.37-1.42 T | ≥1027 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N50H | 47-51 | 1.40-1.45 T | ≥1033 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N52H | 50-53 | 1.42-1.46 T | ≥1043 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N54H | 50-55 | 1.44-1.49 T | ≥1043 kA/m | ≥1353 kA/m | 120°C (248°F) |
| N33SH | 33-35 | 1.12-1.16 T | ≥836 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N35SH | 35-37 | 1.17-1.22 T | ≥876 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N38SH | 36-39 | 1.22-1.25 T | ≥907 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N40SH | 38-41 | 1.25-1.28 T | ≥939 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N42SH | 40-43 | 1.28-1.32 T | ≥963 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N48SH | 45-49 | 1.37-1.42 T | ≥1011 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N50SH | 47-51 | 1.40-1.45 T | ≥1003 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N52SH | 49-53 | 1.42-1.46 T | ≥1003 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N54SH | 50-55 | 1.44-1.49 T | ≥1003 kA/m | ≥1592 kA/m | 150°C (302°F) |
| N28UH | 26-29 | 1.04-1.08 T | ≥764 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N30UH | 28-31 | 1.08-1.13 T | ≥812 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N33UH | 31-34 | 1.13-1.17 T | ≥852 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N35UH | 33-36 | 1.17-1.22 T | ≥860 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N38UH | 36-39 | 1.22-1.25 T | ≥899 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N40UH | 38-41 | 1.25-1.28 T | ≥939 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N42UH | 40-43 | 1.28-1.32 T | ≥963 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N45UH | 43-46 | 1.32-1.38 T | ≥979 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N48UH | 45-49 | 1.37-1.43 T | ≥1011 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N50UH | 47-51 | 1.40-1.45 T | ≥1035 kA/m | ≥1990 kA/m | 180°C (356°F) |
| N28EH | 26-29 | 1.04-1.108 T | ≥780 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N30EH | 30-32 | 1.08-1.13 T | ≥812 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N33EH | 31-34 | 1.13-1.17 T | ≥836 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N35EH | 33-36 | 1.17-1.21 T | ≥876 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N38EH | 36-39 | 1.22-1.25 T | ≥899 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N40EH | 38-41 | 1.25-1.28 T | ≥923 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N42EH | 40-43 | 1.28-1.32 T | ≥931 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N45EH | 43-46 | 1.32-1.38 T | ≥979 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N48EH | 45-49 | 1.37-1.43 T | ≥979 kA/m | ≥2388 kA/m | 200°C (392°F) |
| N28AH | 26-29 | 1.04-1.08 T | ≥787 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N30AH | 28-31 | 1.08-1.13 T | ≥819 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N33AH | 31-34 | 1.13-1.17 T | ≥843 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N35AH | 33-36 | 1.17-1.22 T | ≥876 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N38AH | 36-39 | 1.22-1.25 T | ≥899 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N40AH | 38-41 | 1.25-1.28 T | ≥923 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N42AH | 40-43 | 1.28-1.32 T | ≥931 kA/m | ≥2624 kA/m | 230°C (428°F) |
| N45AH | 43-46 | 1.32-1.38 T | ≥932 kA/m | ≥2624 kA/m | 230°C (428°F) |
Key Takeaways
- Standard Grades (N30-N52): Suitable for applications with operating temperatures up to 80°C.
- High-Temperature Grades: Designed for environments with elevated temperatures, ranging from 100°C to 230°C.
- Performance Trade-offs: Higher temperature resistance comes at the expense of a limit on its maximum magnetic energy.
Key Considerations for Temperature Performance.
The excellent physical and mechanical properties of neodymium magnets determine their excellent strength and magnetic properties. These magnets have a rare earth density of approximately 7.4–7.5 g/cm³, making them relatively compact but very powerful.
Their mechanical strength also deserves special praise – a compressive strength of up to 950 MPa (137,800 psi), while a tensile strength of about 80 MPa (11,600 psi) and a Vickers hardness (Hv) between 560 and 600.
The durability and resistance to external forces of the magnet block are ensured.
In terms of thermal properties, neodymium magnets exhibit anisotropic behavior. The coefficient of thermal expansion along the magnetization direction is 5.2 × 10⁻⁶ /°C, while the coefficient of thermal expansion in the perpendicular direction is -0.8 × 10⁻⁶ /°C, meaning that temperature fluctuations have different effects on dimensional stability depending on the orientation. The Curie temperature range is 310°C to 330°C, and the thermal conductivity of 7.7 kcal/(m·h·°C) plays a role in heat dissipation, a factor to consider in high-power applications. .
Typical electrical resistivity measurements for neodymium magnets are 150–160 µΩ·cm, which, while relatively high for metals, is still lower than that of insulating materials. This makes NdFeB magnets susceptible to eddy currents in AC applications.
Property | Symbol | Unit | Value |
Density | D | g/cm³ | 7.4 – 7.5 |
Compression Strength | C.S | MPa (psi) | 950 (137,800) |
Tensile Strength | σUTS | MPa (psi) | 80 (11,600) |
Vickers Hardness | Hv | D.P.N | 560 – 600 |
Young’s Modulus | E | GPa (ksi) | 160 (23,200) |
Poisson’s Ratio | ν | — | 0.24 |
Electrical Resistivity | ρ | µΩ·cm | 150 – 160 |
Thermal Conductivity | k | kcal/(m·h·°C) | 7.7 |
Specific Heat Capacity | c | J/(kg·°C) | 350 – 500 |
Thermal Expansion Coefficient (Parallel) | C// | 10⁻⁶/°C | 5.2 |
Thermal Expansion Coefficient (Perpendicular) | C⊥ | 10⁻⁶/°C | -0.8 |
Curie Temperature | Tc | °C | 310 – 330 |
3 Common Neodymium Magnet Measurement Systems.
When measuring the performance of magnets, three main measurement systems are commonly used: the CGS (centimeter-gram-second) system, the SI (International System of Units), and the English system. Each system has its own unique units to describe magnetic properties, and conversion between different units is critical for consistency in actual use.
- CGS System (Centimeter-Gram-Second System)
The CGS system has historically been widely used in physics and magnetism studies. Key magnetic measurement units in this system include: Flux (Ø)–Maxwell, Flux Density (B)–Gauss (G), Magnetizing Force (H)–Oersted (Oe), Magnetomotive Force (mmf or F): Gilbert (Gb); - SI system (International System of Units)
The SI system is a globally recognized standard for scientific and engineering measurements. These include: Flux (Ø)–Weber (Wb), Flux Density (B)–Tesla (T), Magnetizing Force (H)–Ampere-turns per meter (A/m), Magnetomotive Force (mmf or F)–Ampere-turn (At); - English System
Though less common in modern scientific applications, the English system is still used in some industrial and engineering settings: Flux Density (B)–Lines per square inch, Magnetizing Force (H)–Ampere-turns per inch (At/in), Magnetomotive Force (mmf or F)–Ampere-turn (At);
| Unit | cgs System | SI System | English System |
|---|---|---|---|
| Length (L) | centimeter (cm) | meter (m) | inch (in) |
| Flux (Ø) | Maxwell | Weber (Wb) | Maxwell |
| Flux Density (B) | Gauss (G) | Tesla (T) | lines/in2 |
| Magnetizing Force (H) | Oersted (Oe) | Ampere turns/m (At/m) | Ampere turns/in (At/in) |
| Magnetomotive Force (mmf or F) | Gilbert (Gb) | Ampere turn (At) | Ampere turn (At) |
Conversions between systems.
Because different industries and regions use different measurement systems, learning how to convert between them can help communicate across regions. Here are 3 key conversion formulas:
1 Oersted (Oe) ≈ 79.62 A/m
10,000 Gauss (G) = 1 Tesla (T)
1 Maxwell = 10⁻⁸ Weber (Wb)
In summary, understanding the various grades and specifications of neodymium magnets is essential to selecting the right magnet for your specific application. Whether you need magnets with superior strength, high temperature resistance, or custom shapes, Osencmag has you covered. With our advanced manufacturing capabilities, we can produce neodymium magnets in any shape, any magnetic grade, and any temperature range, ensuring you get the perfect solution for your project.
FAQs
What is the difference between N35 and N52 magnets?
N52 magnets are stronger than N35, with a higher BHmax. However, N35 may be more cost-effective and suitable for less demanding applications.
What temperature grades are available for Neodymium magnets?
Common grades include N (80°C), M (100°C), H (120°C), SH (150°C), UH (180°C), EH (200°C), and AH (230°C), indicating their maximum operating temperatures.
What is the BHmax of a Neodymium magnet?
BHmax (maximum energy product) measures the magnet’s strength. For example, N52 has a BHmax of 52 MGOe, while N35 has 35 MGOe.
Are higher-grade magnets always better?
Not necessarily. Higher grades offer more strength but may be more brittle, expensive, or less stable at high temperatures.
What coatings are available for Neodymium magnets?
Common coatings include nickel, zinc, epoxy, and gold, which protect against corrosion and wear. Click here to learn more about diamond surface coating types.
Why do Neodymium magnets need coatings?
Neodymium magnets are prone to corrosion, coatings enhance durability and lifespan, especially in harsh environments.
What is the pull force of a Neodymium magnet?
Pull force depends on grade, size, and shape. Higher grades and larger Neodymium magnets generally have greater pull force.
Can neodymium magnets be demagnetized?
Neodymium magnets will demagnetize when exposed to high temperatures, strong diamagnetic fields, or physical damage.
Can neodymium magnets be processed after production?
Because neodymium magnets are fragile and there is a risk of demagnetization due to heat or stress, secondary processing is not recommended.
