Key takeaways
- The listed NdFeB Br reference is 1.17–1.48 T; the ferrite examples span 0.20–0.46 T. These are examples, not complete family limits.
- The ratio of the upper Br examples is about 3.2, not 6–7. Br and BHmax are different properties.
- Temperature and opposing-field checks are needed for both materials; a material name does not guarantee continuous operation.
- Ferrite’s oxide chemistry and NdFeB’s corrosion susceptibility affect protection choices. Qualify the actual environment.
Overview
Overview
NdFeB and hard ferrite are used in permanent-magnet circuits with different packaging and output requirements. NdFeB reference grades have higher remanence and energy product than the ferrite examples here. The change in magnet volume, pull force or motor output requires a circuit calculation; it cannot be read directly from a BHmax ratio.
Side-by-side
Side-by-Side Comparison
Reference properties and design questions. A count of comparison points does not establish a material or supplier recommendation.
| Criterion | NdFeB (Neodymium) | Ferrite (Ceramic) |
|---|---|---|
| Br reference examples | 1.17–1.48 T at room temperature | 0.20–0.46 T at room temperature |
| Energy product | Use a named grade’s BHmax at the required temperature | Use a named grade’s BHmax at the required temperature |
| Temperature and demagnetization | Assess material curves, geometry and opposing fields | Assess material curves, geometry and opposing fields, including cold duty |
| Protection | Coating or enclosure usually needs qualification | Evaluate the oxide ceramic and any surface treatment for exposure |
| Handling | Brittle | Brittle |
| Cost | Current part quotation | Current part quotation |
| Regulatory assessment | Actual item, product and transaction | Actual item, product and transaction |
Confirm source conditions and the actual part requirements before using reference values as acceptance limits.
Use cases
Conditions for considering each option
When NdFeB (Neodymium) wins
- The selected NdFeB grade meets output requirements within the package.
- The coating, retention and cost fit the equipment.
When Ferrite (Ceramic) wins
- The ferrite design meets output requirements with the available space.
- Its part and system costs fit the programme after qualification.
How to choose
Decision Framework
Decision framework
Calculate the required field or force in the actual geometry at operating temperature, then compare both complete designs. MRI gradient fields are made by current-driven coils; they are not a use case for either permanent-magnet material. Some MRI main-field arrays use permanent magnets and require a separate design study.
Specs
Related NdFeB Grades
N35
80°C classN35 reference: 33–36 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N42
80°C classN42 reference: 40–43 MGOe at 20°C, with a nominal 80°C temperature class.
Reference; drawing review required
N42SH
150°C classN42SH reference: 40–43 MGOe at 20°C, with a nominal 150°C temperature class.
Reference; drawing review required
Industries
Related Applications
Industrial Automation
NdFeB magnets for stepper motors, servo drives, linear actuators, magnetic couplings, and factory automation equipment across European and North American manufacturing.
EV Motors
NdFeB magnet design inputs for permanent-magnet traction motors, auxiliary drives and e-axles.
Robotics
NdFeB design inputs for robot joint motors, compact actuators and servo drives.
Questions
Frequently Asked Questions
Are neodymium magnets stronger than ferrite?
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The reference NdFeB grades have higher Br and BHmax than the ferrite examples here. These properties do not establish one pull-force ratio. Geometry, working gap, surrounding steel and temperature determine the usable output.
Can ferrite handle higher temperatures?
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Some ferrite grades are considered for temperatures beyond common NdFeB classes. Use the named material’s curves and actual load line across the full temperature range, including cold demagnetization checks.
Which has the lower installed cost?
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Compare validated designs and current quotations. Magnet mass, tooling, coating and assembly all affect installed cost; a price-per-kilogram ratio alone cannot decide it.
Do ferrite magnets need coating?
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Ferrite is an oxide ceramic and often used uncoated. Check chemical exposure, cleanliness and mechanical protection for the actual application rather than assuming immunity to every environment.
Does using ferrite remove EU CRMA obligations?
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No blanket exemption follows from switching to ferrite. Article 28 of Regulation (EU) 2024/1252 includes ferrite among the magnet types identified in covered products. Product labeling and Article 29 recycled-content duties have different scopes and timing; assess the actual product and current implementing rules.
Need help deciding?
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