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