Neodymium magnets coating

Neodymium magnets coating is used to protect the neodymium magnets. Sintered Neodymium is highly prone to oxidation and corrosion. Therefore the use of different coatings is essential for protection. These improve the magnet’s lifespan and ensure a high-quality product.

Plating is done after machining. It is done in different factory because of environmental laws. The plated neo magnets are then sent back to the factory for inspections.

In recent years special passivated alloys such as HAST have been developed which arrest the oxidation process without the magnet needing a more traditional, thick plating – this is coded NCNd in Magma.

Neodymium magnets coating types:

Surface treatment Type Typical thickness Color Remarks Recommended max. temperature
Nickel coating Ni+NI  


10-20 µm

Silver (semi bright) Excellent resistance to humid atmosphere  




Ni+Cu+NI superior resistance to humid atmosphere
Zinc coating Blue Zn 8-20 µm Silver blue Good resistance to salt spray  


Color Zn Excellent resistance to salt spray
Tin coating Ni+Cu+Sn 15-20 µm Silver semi bright superior resistance to humid atmosphere 160°C
Cupper coating Ni+Cu 10-20 µm Gold shining Temporary treatment
Epoxy Ni+Cu+epoxy 15-25 µm black Excellent climatic and salt spray resistance  


Single epoxy
Chemical coating Ni 10-20 µm Silver semi bright Excellent resistance to humid atmosphere
Passivation 0.1-0.3 µm Silver gray Temporary protection 240°C

Please contact us for further information about our Permanent magnets. We can supply all types and shapes of magnets and we will be happy to consult your company in thus matter.