N42sh magnet

The 'N42' refers to the Maximum Energy Product (BHmax), which for this grade is typically 40-43 MGOe. The 'SH' suffix is critical as it denotes Super High Coercivity, meaning the magnet can operate at temperatures up to 150°C (302°F) without permanent demagnetization. Buyers must verify the Intrinsic Coercive Force (Hcj), which should be ≥20 kOe, and the Remanence (Br), typically between 12.8-13.2 kGs.

Since Neodymium magnets are highly prone to corrosion, selecting the right plating is vital. Ni-Cu-Ni (Nickel-Copper-Nickel) is the standard for general use. For high-humidity or outdoor environments, Epoxy coating provides superior salt spray resistance (up to 48-96 hours). For medical or food-grade applications, Gold or Everlube coatings are recommended to ensure chemical stability and biocompatibility.

Suppliers must provide RoHS (Restriction of Hazardous Substances) and REACH certifications to ensure the magnets do not contain prohibited chemicals. For automotive applications, look for IATF 16949 certification. Additionally, because magnets are considered 'Dangerous Goods' for air transport, a Magnetic Test Report from a recognized body (like DGM) is mandatory to prove the magnetic field strength at a specific distance meets IATA PI953 regulations.

Buyers should request a Hysteresis Graph (Demagnetization Curve) for the specific batch to confirm magnetic properties. For physical dimensions, a Tolerance check (standard is ±0.05mm) using digital calipers is necessary. Flux density testing using a Gauss meter or a Helmholtz Coil for total magnetic flux is the most reliable way to ensure consistency across thousands of units.

The biggest risk is Magnetic Leakage, which can interfere with aircraft navigation systems. If shipping by air, you must use Shielded Packaging (iron sheets and foam). Another risk is Brittleness; Neodymium is a ceramic-like material that chips easily. Ensure the supplier uses vacuum-sealed inner packaging and reinforced wooden crates for sea freight to prevent moisture ingress and physical impact.

Pricing for N42sh is heavily influenced by the market price of Praseodymium-Neodymium (PrNd) metal. It is wise to negotiate a floating price mechanism tied to rare earth indices for long-term contracts. For MOQs, while standard sizes may have lower requirements, custom shapes (arc, countersunk, or segmented) usually require an MOQ of 500-1,000 pieces to offset the wire-cutting and tooling costs.

Always use Trade Terms that include third-party inspection. Before the final payment, hire an inspection service to perform a Pull Force Test and Salt Spray Test. For secure payments, sourcing through reputable platforms like Made-in-China.com allows you to utilize Secured Trading Services, ensuring funds are only released once the Bill of Lading is verified and quality is confirmed.

Because N42sh magnets are often used in EV motors and sensors, they are sensitive to external magnetic fields during transit. Ensure the Polarity Marking is clear on the outer carton to assist in assembly. For shipping to the US or EU, ensure the Harmonized System (HS) Code 8505.11 is used correctly to avoid customs delays and ensure proper duty calculation.