Key takeaways
- NdFeB can have higher room-temperature energy product, but hot performance must be compared at the intended working point.
- Arnold RECOMA 35E SmCo lists BHmax of 32.0 MGOe minimum and 33.3 MGOe nominal; 32 MGOe is not a universal SmCo ceiling.
- RECOMA 35E lists a Br temperature coefficient of -0.035%/°C. This coefficient belongs to that material and its stated test range.
- Corrosion, coating and outgassing requirements apply to the finished part and assembly. Neither material name guarantees all-environment resistance.
Overview
Overview
NdFeB and SmCo are rare-earth permanent-magnet families with several grades. NdFeB is often evaluated for high room-temperature energy product, while SmCo is considered for field stability and elevated-temperature operation. Compare named material curves and the full system cost; a universal temperature crossover cannot decide the design.
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) | SmCo (Samarium-Cobalt) |
|---|---|---|
| BHmax example | N42 reference: 40–43 MGOe at 20°C | Arnold RECOMA 35E: 32.0 minimum, 33.3 nominal MGOe |
| Br temperature coefficient example | Reference table: approximately -0.12%/°C | RECOMA 35E: -0.035%/°C within the sheet’s conditions |
| Working temperature | Grade, geometry and load dependent | Grade, geometry and load dependent |
| Corrosion protection | Qualify coating or enclosure for exposure | Evaluate the actual alloy and environment |
| Mechanical handling | Brittle; protect against impact and clamping stress | Brittle; protect against impact and clamping stress |
| Cost and supply | Quote the qualified part | Quote the qualified part |
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 qualified NdFeB material gives the required hot field within the available volume.
- Its protection system and part cost fit the equipment.
When SmCo (Samarium-Cobalt) wins
- The selected SmCo material meets a field-stability or hot-operation requirement.
- The material and finished-part environmental tests support the intended use.
How to choose
Decision Framework
Decision framework
Use material curves at the required temperatures and evaluate the load line and opposing fields. Compare magnetic output, packaging, retention, coating and full part cost. The RECOMA example is a named external material, not a Mainrich supply claim.
Specs
Related NdFeB Grades
N42UH
180°C classN42UH reference: 40–43 MGOe at 20°C, with a nominal 180°C temperature class.
Reference; drawing review required
N45UH
180°C classN45UH reference: 43–46 MGOe at 20°C, with a nominal 180°C temperature class.
Reference; drawing review required
N42EH
200°C classN42EH reference: 40–43 MGOe at 20°C, with a nominal 200°C temperature class.
Reference; drawing review required
N38EH
200°C classN38EH reference: 36–39 MGOe at 20°C, with a nominal 200°C temperature class.
Reference; drawing review required
Industries
Related Applications
Questions
Frequently Asked Questions
Which has the higher energy product?
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Many NdFeB grades have higher room-temperature BHmax than SmCo grades. Compare actual values at the required temperature. RECOMA 35E lists 33.3 MGOe nominal and 32.0 minimum, so SmCo cannot be described as universally capped at 32 MGOe.
When should I evaluate SmCo?
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Evaluate it where a named SmCo grade’s hot curves and field stability suit the design. Confirm corrosion, handling, coating and outgassing requirements for the finished assembly.
Is either material always cheaper?
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No fixed cost ratio applies to every grade and geometry. Compare current part quotations, tooling and qualification costs for equivalent validated performance.
Need help deciding?
Share your drawing, operating conditions and acceptance requirements for review. Human response within 1 business day.