Application Overview
Aerospace and defense applications represent the most demanding thermal envelope commercial NdFeB can address. Aircraft flight-control servos, auxiliary power units, and satellite actuators routinely operate at 150–200°C; downhole oil-and-gas tools exceed that briefly; some defense radar and servo systems demand 200°C continuous duty with stringent coercivity margin. UH and EH grades with GBD processing are standard; alternative materials (SmCo2:17) are evaluated alongside for every new design.
Why NdFeB for Aerospace & Defense
NdFeB delivers higher energy density than SmCo at comparable temperature ratings, which matters for weight-sensitive aerospace applications. For specific thermal envelopes SmCo may still be correct — but NdFeB with modern GBD processing has extended the upper boundary of where NdFeB is competitive considerably.
Key Design Requirements
Extreme temperature stability
Aerospace actuators commonly rated 180°C; defense and downhole to 200°C. UH or EH grade with GBD processing is standard.
Export licensing
Defense and defense-adjacent applications face intense MOFCOM scrutiny; some applications will be denied. Licensing must be addressed at specification time, not at shipment.
Traceability & documentation
Full material provenance from rare earth source to finished magnet. AS9100 supplier quality systems expected for aerospace primes.
Qualification rigor
DO-160 environmental qualification (aerospace), MIL-STD-810 (defense). Expect extended qualification programs.
Recommended NdFeB Grades for Aerospace & Defense
Grade selection depends on the specific duty cycle, operating temperature, and torque requirements of your design. Below are the most common specifications used for aerospace & defense.
N35UH
180°C · Ultra High Temperature (UH)Ultra-high-temperature NdFeB grade rated for 180°C continuous service in aerospace and traction applications.
N42UH
180°C · Ultra High Temperature (UH)High-performance UH-grade NdFeB for the most demanding traction, aerospace, and industrial motor applications.
N45UH
180°C · Ultra High Temperature (UH)Top-tier UH-grade NdFeB — rare production, reserved for the highest-performance traction and aerospace motors.
N35EH
200°C · Extreme High Temperature (EH)Extreme-temperature NdFeB grade for 200°C continuous service — aerospace, downhole, and defense applications.
N38EH
200°C · Extreme High Temperature (EH)Higher-flux EH-grade NdFeB for the most demanding 200°C applications in aerospace and energy.
N42EH
200°C · Extreme High Temperature (EH)Highest commercial EH-grade NdFeB — the upper limit of 200°C NdFeB in production today.
Typical Magnet Configurations
- •Arc segments for flight-control servo motors
- •Small rings and blocks for satellite reaction wheels and attitude-control actuators
- •Specialized assemblies for downhole drilling tools and logging equipment
- •Precision blocks for radar and countermeasure systems
Typical dimensions: Typically small precision components — arc segments 15–50mm, blocks 10–40mm principal dimensions, rings 20–80mm OD.
Design & Procurement Considerations
- 01Evaluate SmCo2:17 alongside NdFeB for any design above 200°C — SmCo has inherently better thermal stability and may win on total-cost-of-ownership despite lower BHmax.
- 02For programs requiring US-origin material, investigate MP Materials and Quadrant supply as part of dual-source strategy.
- 03Export licensing timeline must be built into the program schedule from the outset — expect 10–16 weeks for UH/EH grades.
- 04Qualification documentation burden is substantial — budget accordingly in supplier selection.
Frequently Asked Questions
Can NdFeB magnets be used for defense applications?
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Yes for commercial and most defense-adjacent programs; some explicitly military applications will not receive MOFCOM export licensing from Chinese suppliers. Discuss the end-use profile with your supplier early — a capable supplier will tell you candidly whether the application is approvable before accepting the order.
What NdFeB grade works at 200°C?
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N35EH, N38EH, or N42EH grades are rated for 200°C continuous operation. These grades have ≥30 kOe intrinsic coercivity at 20°C with GBD processing as effectively standard. Above 200°C, SmCo2:17 typically becomes the more practical magnet choice.
Do aerospace NdFeB magnets require AS9100 supplier certification?
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Aerospace prime contractors typically require AS9100 or equivalent quality systems from their magnet supply chain, though this varies by program and tier. Some accept IATF 16949 with documented AS9100-compatible process controls as an alternative. Confirm specific prime requirements early in qualification.
Request a Quote for Aerospace & Defense
Share your application, target dimensions, operating temperature, and annual volume. Our UK-based engineering team responds within 1 business day with grade recommendation, followed by pricing and lead time typically within 2 business days.