Typical Surface Treatment

Coating Coating thickness Salt spray test PCT test Glue performance Characteristic
NiCuNi coating 10~30μm 48hrs 96hrs Not good Non-conductive, with excellent resistance to salty, heat and humidity. But with uneven coating thickness for complex magnets
Zn coating              (with blue passivation) 5~10μm 24hrs 24hrs Good Non-conductive, with normal resistance to salty and heat. Low cost 
Zn coating                (with color passivation) 5~10μm 72hrs 24hrs Good Non-conductive, with excellent resistance to salty and heat. 
Expoxy coating 5~10μm 48hrs 96hrs Good With excellent waterproof, anti-chemical erosion, and adhesion strength, and have sufficient hardness, especially with minimum water absorption and permeability. But with weak abrasion performance and anti-scratch resistance, low heat-resistance.
Chemical Ni coating 20~30μm 72hrs 96hrs Not good With compact coating structure, thickness uniformity, high hardness and corrosion resistance, little effect on the magnetic properties
Phosphated 2~3μm \ \ Better Temporary protection of the magnets