Neodymium magnets have different grades, like N35, N42, N52, etc.
It can be confusing for you, if you are a beginning buyer for these strongest rare earth magnets.
This post will explain what the different letter and number in a grade’s name mean.
After reading, you’ll be able to pick the right grade for your application.
Definition
Neodymium magnets are graded according to their maximum energy product.
- The grades relate to the magnetic flux output per unit volume.
- The grades generally available range from N30 to N52.
- Higher numbers indicate stronger magnets.
Some key points about neodymium magnet grades:
The names all start with “N” for neodymium.
The number that follows represents the maximum energy product in Mega-Gauss Oersteds (MGOe).
- For example, grade N42 has a maximum energy product of 42 MGOe.
Common commercial grades range from N35 up to N55.
- N54 currently being the highest grade that Osenc can offer.
Higher grade numbers indicate stronger magnets.
- An N52 magnet is about 20% stronger than an N42 magnet, but can cost twice as much.
Letters after the grade number indicate the maximum operating temperature.
Standard neodymium magnets can be used up to 80°C (176°F).
Grades like N42M, N42H, N42SH, N42UH have progressively higher temperature ratings up to 230°C.
For a given application, using a higher grade allows the magnet size to be smaller.
- However, if space allows, using a larger size of a lower grade like N42 is more economical than a smaller higher grade like N52.
So in summary, neodymium magnet grades are designated by an “N” followed by a number representing the maximum energy product in MGOe, with optional letters indicating the maximum operating temperature.
The most common grades used range from N35 to N52.
Choosing the optimal grade depends on the strength required and the operating conditions.
Grade Ranges
Neodymium magnets are available in a range of grades that indicate their magnetic strength and maximum operating temperature.
Here is an overview of the different levels of neodymium magnet grades:
Entry Level Grades
N30 and N33:
- These are the lowest strength neodymium grades commonly available.
- N33 magnets are about 3% stronger than N30.
- They have a maximum operating temperature of 80°C (176°F).
Standard Grades
N35:
- A common economical grade with reasonable strength of 33-36 MGOe (263-287 kJ/m3).
- Available with maximum operating temperatures from 80°C up to 240°C.
N38 and N40:
- Slightly stronger than N35
- N38 at 36-39 MGOe and N40 at 38-41 MGOe.
- Also available in high temp versions.
N42:
- A very popular grade offering high strength of 40-43 MGOe at an affordable price.
- It provides a good balance of performance and cost.
N45 and N48:
- High strength grades at 43-46 MGOe for N45 and 45-49 MGOe for N48.
High Performance Grades
N50 and N52:
- The highest strength grades commonly available.
- N50 at 47-51 MGOe and N52 at 49-53 MGOe.
- N52 is considered the strongest neodymium magnet grade readily available.
N55:
- An even higher grade at 53-56 MGOe, but less commonly used.
The number in the grade designation represents the maximum energy product in MGOe (Mega Gauss-Oersteds). Higher numbers indicate stronger magnets.
In summary, neodymium magnets span a wide range of strength grades from entry-level N30 up to high-performance N55, with N35-N45 being common for many applications.
The choice depends on the strength required, operating temperature, and budget constraints. Higher grades provide more strength in a compact size but also cost more.
Performance versus Prices
The N42 and N52 grades of neodymium magnets offer a good balance between performance and price for many applications.
N42
N42 grade neodymium magnets provide high strength at an economical price point.
They have a maximum energy product of 40-43 MGOe and are a popular choice that works well for many uses.
- N42 magnets can achieve similar strength to higher grades like N52 by using a slightly larger size.
- This makes them a cost-effective option.
N52
N52 grade neodymium magnets are the highest strength grade commonly available, with a maximum energy product of 49-53 MGOe.
- However, N52 magnets are significantly more expensive than N42
- Often costing twice as much for the same size while providing about 20% more strength.
So N52 is best when the absolute maximum strength is needed in the smallest size and the higher price is acceptable.
- For applications that don’t require the extreme strength of N52, grades like N42 or N45 can provide very good performance at a lower cost.
- If operating temperatures are slightly elevated in the 140-176°F range, N42 magnets may actually outperform N52, especially in thinner shapes.
In summary, the optimal grade depends on the specific strength, size and budget requirements of the application.
N42 neodymium magnets offer an excellent combination of high strength and reasonable price for many common uses.
N52 is the top choice when maximum strength is absolutely critical and cost is no object.
Mid-range grades like N45 and N48 can also provide a good balance for applications between these extremes.
Grades versus Sizes
There is a relationship between neodymium magnet grades and pull force, but size also plays a significant role.
Here are the key points:
Relationship between grade and pull force:
- Neodymium magnet grades like N35, N42, N52 etc. represent the maximum energy product (BHmax) in MGOe.
- Higher grade numbers indicate stronger magnets.
The pull force a magnet can exert is influenced by its grade or magnetic strength.
In general, higher grade magnets will have a greater pull force than lower grades for the same size and shape.
- For example, an N52 grade magnet is about 40-50% stronger than an N35 magnet of the same dimensions.
However, size is also a major factor:
- The size of the magnet significantly affects its pull force.
- Larger magnets have a greater surface area and can produce a stronger magnetic field, resulting in higher pull force.
- Increasing the magnet size will increase the pull force, even if the grade remains the same.
In many applications, using a larger size magnet of a lower grade like N42 can be more cost-effective than using a smaller higher grade like N52 to achieve the same pull force.
So in summary, to get more pull force, you have two main options:
- Increase the magnet grade (e.g. go from N35 to N52).
- This gives you more strength for the same size but is more expensive.
- Increase the magnet size while keeping the same grade.
- This is often the more economical approach if space allows.
The best choice depends on your specific application constraints like available space, weight, budget etc.
If size is limited, a higher grade may be necessary. But if you have room for a larger magnet, a lower grade can work well at lower cost.
Testing different magnet grades and sizes in your application is recommended to find the optimal balance of performance and cost.
N35 and N52
Magnetic Strength
N52 magnets have a much higher maximum energy product of 49-53 MGOe compared to 33-36 MGOe for N35 magnets.
- This means N52 magnets are about 40-50% stronger than N35 magnets of the same size and shape.
- The residual flux density (Br) is 14.3-14.8 KGs for N52 vs 11.7-12.1 KGs for N35.
Higher Br indicates the magnet can retain a stronger magnetic field.
Price
N52 magnets are significantly more expensive than N35, often costing twice as much for the same size.
- This is because of the higher rare earth content required to achieve the greater magnetic strength.
Applications
N52 magnets are used where the highest magnetic performance is needed in a compact size.
And N35 is more common and cost-effective for general purpose applications.
- If space allows, using a larger size N35 or N42 magnet can be more economical than a smaller N52 for the same strength.
Temperature Rating
Both N35 and N52 have a maximum operating temperature of 80°C (176°F) since they are standard neodymium grades.
For higher temperatures up to 230°C, special high temp grades like N35M, N35H, N35SH, N35UH are available which sacrifice some strength for better heat resistance.
In summary, N52 is the highest strength neodymium magnet grade commercially available, but also the most expensive.
N35 is an economical lower strength grade commonly used.
The choice depends on the strength required, space constraints, operating temperature and budget.
For many applications, intermediate grades like N42 or N45 offer a good balance between performance and cost.