What is a Magnet Grade?
A magnet grade is a standardized code that represents the performance and classification of magnetic materials. While different materials have different naming conventions, they share the same core purpose: helping users quickly understand a magnet’s key properties through simple numbering.
Why Do We Need Grades?
Imagine if every time you purchased magnets, you had to specify “I need a material with this much remanence, this much coercivity, and this much energy product.” This would be tedious and error-prone. Grades package these complex parameters into a simple code, making communication easier across design, procurement, and production teams.
Understanding Neodymium Magnet Grades (Most Common)
2.1 Grade Format: Letter + Number + Letter
Example: N50M
| Component | Meaning | Description |
| First letter N | Neodymium material | Represents the NdFeB series |
| Number 50 | Magnetic strength | Higher number = stronger magnetism |
| Second letter M | Temperature rating | Later letters = higher temperature resistance |
2.2 What the Number Means: Magnetic Strength
The number represents the maximum energy product, the core indicator of magnet strength
Higher numbers produce stronger magnetic fields in the same volume
Common range: N35, N38, N42, N45, N48, N50, N52
Current mainstream products range from N27 to N60
Simple Understanding: Each increase of 3-5 in the number represents approximately 10% stronger magnetism. N52 is about 50% stronger than N35.
2.3 What the Letter Means: Temperature Rating
Neodymium magnets are divided into seven series based on intrinsic coercivity. The later the letter, the higher the temperature resistance:
| Suffix | Max Operating Temperature | Application Scenarios |
| No suffix (e.g., N35) | Below 80°C | General indoor products |
| M (e.g., N35M) | Below 100°C | Motors, automotive electronics |
| H (e.g., N35H) | Below 120°C | Near engines |
| SH (e.g., N35SH) | Below 150°C | Industrial equipment |
| UH (e.g., N35UH) | Below 180°C | High-temperature environments |
| EH (e.g., N35EH) | Below 200°C | Special high-temperature applications |
| TH/AH | Below 230°C | Extreme high-temperature environments |
Note: Actual operating temperature depends on factors like magnet size and coating. The above are reference values.
Four Key Indicators of Magnet Performance
| Parameter | Symbol | Simple Explanation |
| Remanence | Br | How strong a magnetic field the magnet can produce |
| Coercivity | Hcb | Ability to resist general demagnetization |
| Intrinsic Coercivity | Hcj | Core indicator that determines temperature rating |
| Maximum Energy Product | (BH)max | Source of the grade number; comprehensive magnetic strength indicator |
How to Choose the Right Grade？
4.1 Three Steps to the Right Selection
Step 1: Determine Required Magnetic Strength (Look at the Number)
General requirements → N35, N38 (best value)
Limited space, need strong holding force → N42, N45, N48
Extreme miniaturization needs → N50, N52
Step 2: Confirm Operating Temperature (Look at the Letter)
Room temperature indoor use → No suffix or M grade
Equipment that generates heat (motors, engines) → H or SH grade
Special high-temperature environments → UH/EH/TH grade
Step 3: Tell Your Supplier
“I need N50M neodymium magnets, size 10×10×5mm, 1000 pieces.”
One Sentence Summary
Grade = Magnetic Strength Number + Temperature Rating Letter. Tell your supplier these two pieces of information, and you’ll get the right magnets.
Have any questions about selection? Feel free to consult Dahua.
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