Compliant Sourcing of EH Grade High-Temp NdFeB Magnets – China Guide for Controlled Rare Earth Magnets
For importers who need magnets to operate continuously at 180℃ (such as in injection molding processes or motors), SH-grade magnets often suffer irreversible demagnetization, making EH grade or higher magnets a mandatory choice. However, due to Chinese export regulations and logistical restrictions on heavy rare earth elements (such as Dysprosium and Terbium), directly purchasing high-grade magnets often faces high costs and complex compliance reviews. There are two most efficient paths to solving this problem: First, directly purchase assembled magnetic components (such as rotors or injection-molded parts) to minimize export compliance risks. Second, purchase unmagnetized standard N-grade magnets, complete high-temperature processes such as injection molding, and then magnetize them locally. This fundamentally solves the problem of high-temperature demagnetization.
1. What Are Controlled Elements in Neodymium Magnets?
In the production of neodymium magnets, in order to improve the Intrinsic Coercivity (Hcj) of the magnet and prevent it from demagnetizing at high temperatures, it is usually necessary to add heavy rare earth elements (HREE), mainly dysprosium (Dy) and terbium (Tb).
These elements are global strategic resources and key items in Chinese export control catalog. EH (Extra High) grade and higher magnets contain a high proportion of dysprosium or terbium, subjecting them to stricter procedures for export customs declaration, logistics inspection, and magnetic inspection reports.
2. What are Chinese Restricted Regulations on Heavy Rare Earth Magnets？
As the core of the global magnetic material supply chain, China enforces strict processes for the export of high-grade magnets:
- Magnet Inspection Report: All magnetic products exported require a magnet inspection report issued by an officially accredited third-party institution. This report is to analyze the rare earth elements in magnets and confirm whether the magnets contain controlled elements. Testing costs approximately $240 per batch, with a verification window of about 10 working days.
- Export License: Companies importing magnetic products with controlled elements must apply for a license. The license application process takes 60 working days and requires certifications of end-use and end-user.
To reduce reliance on heavy rare earths, leading Chinese factories have fully adopted Grain Boundary Diffusion (GBD) technology. This process achieves EH-grade high coercivity with reduced dysprosium/terbium usage, delivering better compliance and cost advantages.
3. How to Compliantly Source Controlled Neodymium Magnets from China？
For applications requiring continuous operation at 180℃, optimizing the production chain is more practical than purchasing costly EH-grade magnets:
3.1 Procure Magnetic Assemblies
If you wish to avoid the complexities involved in applying for China’s Dual-Use Export License, procuring complete magnetic assemblies represents the most efficient “fast track” currently available.
·HS Code Compliance Advantages: Under China’s new regulations effective post-2025, magnets containing 0.1% Dysprosium (Dy) or Terbium (Tb) fall under a category subject to strict regulatory controls. However, when magnets are exported as assembly — such as rotors, stators, or components within injection-molded assemblies—their HS classification typically falls under “motor parts” . This classification often allows them to bypass the stringent licensing requirements otherwise imposed on raw magnet materials.
·One-Stop Delivery: The surface mounting (SPM) or internal mounting (IPM) of magnets demands exceptionally high precision. By having our factory directly oversee the integrated production process—encompassing the magnets, metal components, and injection-molded encapsulation—we guarantee that the finished assemblies meet the required standards for dynamic balance and magnetic flux.
·Accelerated Production Cycles: Our components are delivered as “plug-and-play” units, thereby eliminating the need for you to perform complex magnetic circuit assembly and testing procedures locally. By consolidating a multi-tiered supply chain into a single point of supply, we significantly mitigate your operational and management risks.
3.2 Procure Unmagnetized Magnets
If you have local magnetization equipment: We strongly recommend procuring unmagnetized blanks or finished products. This cuts substantial costs and completely eliminates thermal demagnetization rejection rates on production lines.
·Eliminate Demagnetization Risks: Unmagnetized N-grade magnets have an extremely stable physical structure. They face zero demagnetization risk during extreme high temperature, as magnetic domains remain unaligned. In processes such as injection molding, mold temperatures typically exceed 180°C. Under these conditions, pre-magnetized magnets (even those of the high-grade EH series) are highly susceptible to magnetic domain disorder. By adopting a “mold-first, magnetize-later” process logic, the magnets remain in an unmagnetized state while exposed to high temperatures; their physical properties remain exceptionally stable, allowing for a yield rate of up to 100%.
·Cost Reduction: Standard N-grade magnets cost 30%-50% less than premium EH-grade magnets. And unmagnetized magnets are classified as “general cargo,” thereby eliminating the need to pay the fee for an Air Transport Magnetic Inspection Report.
·Technical Note: Ensure that your local magnetization equipment possesses sufficient saturation magnetization capacity. Typically, the applied magnetization field strength must reach 3 to 5 times the magnet’s intrinsic coercivity (Hcj) to ensure that its full magnetic potential is fully activated.
Compliant solutions to the controlled magnets
| Features | Direct Procurement of EH Grade Magnets | Procure Magnetic Assemblies (ODM/OEM) | Procure Unmagnetized Magnets (Local Magnetization) |
| Temperature Limit | 200°C (grade-dependent) | Ultra-high (optimized by manufacturers) | Unlimited (no magnetic loss before magnetization) |
| Export Compliance Complexity | Strict (controlled heavy rare earths) | Moderate (declared as components) | Simple (non-strong magnetic goods) |
| Logistics Cost | High (magnetic inspection fees + air freight restrictions) | Medium | Low |
| Technical Risk | High (demagnetization during high-temp injection molding) | Zero (manufacturer guarantees assembly precision) | Zero (magnetization post-injection molding) |
4. What Are the Application Fields of EH Magnets?
- HDPE/Plastic Injection Molding Packaging: The unmagnetized solution is an industry standard for fishing gear, sensors, and other products requiring magnets to be encapsulated in 180℃ plastic.
- Automotive Motor Rotors: For heat generated by high-speed rotation, procuring pre-balanced rotor assemblies significantly improves motor power density.
- Oil Exploration Equipment: Ultra-deep downhole environments demand extreme durability of magnetic performance.
5. FAQs
Q1: Why do my SH–grade magnets fail after 20 seconds at 180℃?
A1: SH-grade magnets have a theoretical temperature limit of 150℃. At 180℃, internal magnetic domains become irreversibly disorganized. For short-term high-temperature and high-pressure environments (e.g., inside injection molding machines), EH-grade magnets with high coercivity or a post-magnetization process is required.
Q2: What precautions should I take when purchasing unmagnetized magnets?
A2: Ensure your local magnetizer has sufficient voltage and electromagnetic force to penetrate the product (especially for multi-pole magnetization). Request the required magnetization current parameters from your supplier.
Q3: Is a Magnet Inspection Report necessary?
A3: Yes. Due to Chinese rare earth export controls, all exported magnetic products require magnet shielding and composition testing. Fees typically range from $200 to $300 per batch, with an verification of about 10 working days.
Q4: What is Grain Boundary Diffusion (GBD) Technology?
A4: It is an advanced process that achieves EH/AH grade coercivity with minimal heavy rare earth usage. GBD magnets offer higher cost performance and align with export trends while meeting equivalent temperature resistance requirements.
Contact Us
As a manufacturer with the complete motor industry chain in China, we specialize in SH/UH/EH/AH grade magnets and precision magnetic components. Whether you need technical drawing evaluation or process optimization for injection molding, our engineering team is ready to provide full support. Contact us for a customized, compliant, and efficient import solution!