Permanent magnet material

Buyers must prioritize Magnetic Grade (e.g., N35 to N52 for Neodymium), Remanence (Br), and Coercivity (Hcj). High-performance applications require materials with high Maximum Energy Product (BHmax). Additionally, consider the Working Temperature; for instance, standard NdFeB magnets lose magnetism above 80°C, whereas SmCo (Samarium Cobalt) or high-temperature grades (SH, UH, EH) are necessary for extreme environments.

Permanent magnets, especially Neodymium, are highly prone to corrosion. You must specify the Coating Type, such as Ni-Cu-Ni (Nickel), Zinc, or Epoxy. For outdoor or medical use, Everlube or Gold plating may be required. Ensure the supplier provides Salt Spray Test (SST) reports, typically requiring a minimum of 24 to 48 hours of resistance for standard industrial applications.

Products must adhere to RoHS (Restriction of Hazardous Substances) and REACH regulations to ensure they are free from toxic elements. For electronics and automotive sectors, verify IATF 16949 certification. If the magnets are used in toys or consumer goods, compliance with EN71 or ASTM F963 is essential to prevent safety hazards related to small, high-powered magnets.

Request a CPK (Process Capability Index) report from the manufacturer. Standard tolerances for sintered magnets are usually ±0.05mm to ±0.1mm. For high-precision motors, you may require ±0.01mm. Use Gaussian meters or Fluxmeters to verify magnetic field consistency across a batch, ensuring a variance of less than 3-5%.

Magnets are classified as Class 9 Dangerous Goods for air freight if they exceed a certain magnetic field strength. You must ensure the supplier provides Magnetic Shielding Packaging (using iron sheets and foam) and a Non-Dangerous Goods Appraisal Report (DGM report). For sea freight, ensure the packaging is moisture-proof to prevent oxidation during long-transit times.

Always use Secure Payment Terms such as Letters of Credit (L/C) or trade assurance services provided by reputable platforms like Made-in-China.com. Conduct a Factory Audit or hire a third-party inspector (like SGS or Intertek) to perform a Pre-Shipment Inspection (PSI) to verify the magnetic grade and quantity before final payment.

Prices for permanent magnets are heavily influenced by Rare Earth element market fluctuations (e.g., Praseodymium and Neodymium prices). Negotiate a Price Adjustment Formula based on public market indices. For long-term contracts, seek Volume-Based Discounts; purchasing in bulk can often reduce the unit price by 10-20% compared to small trial orders.

Check for Anti-Dumping Duties or specific Section 301 tariffs if importing to the US. Some countries have strict Export Licenses for high-grade magnetic materials used in military or dual-use technologies. Always confirm the HS Code (typically 8505.11) with your customs broker to determine the exact duty rates and import restrictions.