Small magnet

For high-performance applications, Neodymium (NdFeB) is the standard, typically categorized by grades like N35 to N52. Higher numbers indicate stronger magnetic force, while suffixes like M, H, SH, UH, or EH denote temperature resistance (ranging from 80°C to 200°C). If your application involves extreme heat or corrosion, Samarium Cobalt (SmCo) or Ferrite may be more economically feasible despite lower magnetic strength.

Small magnets, especially Neodymium, are highly prone to oxidation. You must specify coatings such as Ni-Cu-Ni (Nickel) for general use, Zinc (Zn) for cost-saving, or Epoxy for superior corrosion resistance in humid environments. Ensure the supplier performs a Salt Spray Test (SST) and provides a report confirming the coating can withstand at least 24 to 48 hours of exposure.

Magnets used in consumer electronics or toys must comply with RoHS (Restriction of Hazardous Substances) and REACH regulations to ensure they are free from lead and cadmium. For products sold in the US, compliance with ASTM F963-17 is critical if the magnets are small enough to be swallowed, as there are strict flux index limits for children's safety.

For precision components, request a tolerance of ±0.05mm or tighter. Professional suppliers should use automated optical inspection (AOI) and provide a Hysteresisgraph test report to prove that the Remanence (Br) and Coercivity (Hcb) meet your technical specifications across the entire batch.

Magnets are classified as Class 9 Dangerous Goods in air transport if they exceed certain magnetic field strengths. You must ensure the supplier provides Magnetic Shielding Packaging (using iron sheets and foam) and obtains a Non-hazardous Goods Declaration or a Magnetic Inspection Report from recognized bodies like DGM to avoid customs seizures or airline rejection.

Use Trade Assurance services on Made-in-China.com to protect your payment until quality is verified. Negotiate a contract that includes a demagnetization rate clause; if more than 1-2% of the batch fails a Gauss meter test upon arrival, the supplier should be liable for replacements. Always request vacuum packaging to prevent moisture ingress during long-term sea freight.

The price of Neodymium is tied to rare-earth market fluctuations. Instead of a fixed annual price, negotiate a formula-based pricing model linked to the Asian Metal Index. For bulk orders, aim for a 10-15% discount by increasing the volume to meet the supplier's raw material processing cycle, which typically requires a minimum of 50kg to 100kg of material.

Before placing a large order, conduct a factory audit or hire a third-party inspector to verify the supplier's ISO 9001 certification and production capacity. On Made-in-China.com, prioritize Audited Suppliers who have undergone comprehensive on-site verification of their business license, production lines, and export capabilities.