Surface Coating

Surface Coating Of Neodymium Magnet

Type Plating Thickness(microns) Color Resistance
Nickel    Ni  10-25    Bright Silver   Excellent against Humidity   
Ni+Epoxy resin Black,  Grey
Zinc   Zn 8-15    Bright Blue Good Against Salt Spray  
C+Zn Light Blue Tint
Znic  Cr3+   Zn 8-15    Bright Blue Good Against Salt Spray
C+Zn Light Blue Tint Excellent Against Salt Spray
Epoxy    Epoxy 15-25    Black, Grey    Excellent Against Humidity & Salt Spray   
Tin Ni+Cu+Sn 15-20 Silver Superior Against Humidity
Au Ni+Cu+Au  10-20  Gold Superior Against Humidity
Ag Ni+Ag  10-20 Silver Superior Against Humidity
Parylene Parylene 5 -20  Transparent Superior corrosion & Salt Spray
Passivation No coating 1- 3  Silver Grey Temporary Protection
Phosphate No Coating 1- 3  Silver Grey Temporary Protection

The most common coating for Neodymium magnets is Nickel + Copper + Nickel (Ni + Cu + Ni). This coating offers the magnet
relatively good protection from corrosion and passive applications. If the magnet will be exposed to moisture or liquid then consider
the use of an organic coating such as Epoxy. A hard wearing coating, Epoxy is suited to applications where the magnet will come
under some friction or knocking.