Technical Data
N40 Technical Specifications
| Parameter | Value |
|---|---|
| Remanence (Br) at 20°C | 12.6–12.9 kGs (1.26–1.29 T) |
| Coercive Force (HcB) at 20°C | ≥11.6 kOe (≥923 kA/m) |
| Intrinsic Coercivity (HcJ) at 20°C | ≥12 kOe (≥955 kA/m) |
| Energy Product (BHmax) at 20°C | 38–41 MGOe (303–326 kJ/m³) |
| Nominal temperature class | 80°C |
| Approximate coefficient (Br) | -0.12 %/°C |
| Approximate coefficient (HcJ) | -0.60 %/°C |
| Density (typical) | 7.5 g/cm³ |
| Vickers Hardness (typical) | 550–650 HV |
Br, HcB, HcJ and BHmax are educational reference values at 20°C. Supplier specifications vary; agree the quoted material and acceptance limits separately. Temperature coefficients are approximate reference values, not a substitute for measured hot curves. Agree any batch measurements and certificate contents in the order specification.
Overview
What Is N40?
N40 is a sintered NdFeB grade in the Standard family. This reference lists 12.6–12.9 kGs (1.26–1.29 T) remanence and ≥12 kOe (≥955 kA/m) intrinsic coercivity at 20°C. The numeric grade describes energy product; the standard N designation does not identify alloy composition or establish a safe operating point.
Applications
Related application design topics
These briefs describe design inputs and qualification questions. They do not confirm this grade for a particular application or geometry.
Surface Protection
Coating candidates for N40
Coating choice is driven by operating environment and assembly method. Qualify the finished coating stack for the actual part:
See our NdFeB Coatings Guide for coating definitions and qualification considerations.
Specifying
Design Considerations When Specifying N40
Key insight
The 80°C class is a preliminary screening value. Check the actual material's hot demagnetization curves against the load line, opposing field and duty cycle.
FAQ
Frequently Asked Questions
What is N40 NdFeB magnet?
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N40 is a sintered NdFeB grade in the Standard family. This reference lists 12.6–12.9 kGs (1.26–1.29 T) remanence and ≥12 kOe (≥955 kA/m) intrinsic coercivity at 20°C. The numeric grade describes energy product; the standard N designation does not identify alloy composition or establish a safe operating point.
What is the maximum operating temperature of N40?
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N40 has a nominal 80°C class in this reference. Nominal temperature classes do not establish a safe operating temperature. Geometry, hot curves, load line, opposing field and duty cycle must be assessed for the actual part.
What is the BHmax of N40?
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N40 has a reference BHmax range of 38–41 MGOe (303–326 kJ/m³) at 20°C. BHmax is the maximum B × H product on the normal demagnetization curve. It does not specify hot output, surface field or pull force. Supplier acceptance values require a material-specific sheet or test record.
What applications use N40 magnets?
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Related design topics include Industrial Automation. These links are educational examples. Grade suitability requires the actual geometry, hot curves, load line, opposing field and duty cycle; the reference properties alone cannot establish it.
Request a drawing review for N40
Mainrich’s company range is N30 to N56. Grade, series, geometry and temperature must be confirmed together. Share your drawing, quantity and operating conditions for review.