Circular magnet

The most critical factor is the magnetic grade, which determines the strength. For Neodymium (NdFeB) magnets, grades range from N35 to N52; higher numbers indicate stronger magnetic pull. If your application involves high temperatures, you must specify grades with high coercivity (H, SH, UH, EH, or AH) to prevent permanent demagnetization above 80°C. For cost-sensitive or outdoor applications, Ferrite (Ceramic) magnets are preferred due to their corrosion resistance and lower price point, though they offer significantly less strength.

Circular magnets are defined by Diameter (D) x Thickness (T). Standard industrial tolerances are typically ±0.05mm to ±0.1mm. For precision engineering or automated assembly, you should request tighter tolerances (±0.02mm) to avoid fitment issues. Always clarify if the magnet is axially magnetized (poles on the flat circular faces) or diametrically magnetized (poles on the curved sides), as this fundamentally changes the product's function.

Raw Neodymium is highly prone to oxidation. The industry standard is Ni-Cu-Ni (Nickel-Copper-Nickel) plating, which provides a smooth, metallic finish. For enhanced salt spray resistance (up to 48-96 hours), consider Black Epoxy or Zinc (Zn) coating. If the magnets are for medical or food-contact use, ensure they meet RoHS and REACH compliance standards to guarantee the absence of hazardous substances like lead or cadmium.

Circular magnets are versatile components used in consumer electronics (speakers, sensors), industrial motors, and magnetic separators. In the retail sector, they are widely used for point-of-purchase (POP) displays and packaging closures. For heavy-duty lifting or holding, Pot Magnets (circular magnets encased in a steel cup) are recommended because the steel housing concentrates the magnetic flux and increases the holding force significantly.

Magnets are classified as 'Dangerous Goods' for air freight because their magnetic fields can interfere with aircraft navigation systems. You must ensure the supplier provides Magnetic Shielding Packaging (using iron sheets and foam) to pass the IATA PI953 inspection. For sea freight, this is less restrictive, but you should still verify that the supplier can provide a Non-Hazardous Goods Declaration or a Magnetic Inspection Report to avoid customs delays.

Request a Hysteresis Graph (Demagnetization Curve) from the supplier to verify the material's magnetic properties. For bulk orders, insist on a Third-Party Inspection (such as V-Trust or SGS) to perform a Gauss Meter test on random samples. On Made-in-China.com, prioritize Audited Suppliers who have undergone on-site manufacturing capability assessments to ensure the factory isn't just a middleman.

Magnet prices are highly sensitive to the market price of Rare Earth elements (Praseodymium-Neodymium). It is wise to negotiate a price adjustment clause based on raw material indices if you are signing a long-term contract. Additionally, ask for tiered pricing based on volume; for circular magnets, increasing the order from 5,000 to 20,000 units can often yield a 15-25% cost reduction due to the efficiency of automated slicing and grinding.

Always use Secured Payment services provided by Made-in-China.com to ensure your funds are held in escrow until shipping documents are verified. Clearly define the Acceptable Quality Level (AQL) in the Proforma Invoice, specifically mentioning that chipped edges or cracked surfaces exceeding 5% of the surface area will be grounds for replacement or refund.