Surface Treatment

Neodymium-Surface-Treatments

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.

Plating / Coating Options

The following is a list and description of available coating options for custom magnets. Note: Magnets can only be electro-plated before magnetization. if the plating is compromised after magnetization via abrasion or deliberate machining they cannot be re-plated. Some coatings such as plastic may be done after magnetization, If the process does not exceed the magnets maximum operating temperature.

Plating \ Coating Appearance Indoor
Use
Abrasion
(Wear)
Humidity Water Salty Air (Near Ocean) Salt Water Thickness Price
Nickel (Ni-Cu-Ni)

A very durable multilayer combination of nickel, copper, nickel. The most common plating.

 Nickle Excellent Good Good Bad Bad Bad 10-20 Microns Low
Zinc Plating (Zn)

2nd most common plating, Zinc is a standalone plating with only one layer. It is a self- sacrificing coating, meaning when the material corrodes the outside turns white creating a durable layer of protection.

 Zinc Excellent Excellent Excellent Good Good Bad 8-10 Microns Low
Epoxy (Ni-Cu-Be)

Epoxy plating is multilayered in Nickel, Copper, Epoxy. Great for outdoor applications. However it is not very abrasion resistant and prone to scratching.

 Epoxy Superior Bad Superior Superior Excellent Excellent 15-25 Microns Medium
Gold (Ni-Cu-Au)

Well known for its corrosion resistance. Layered in Nickel, Copper & Gold on top. Works very well in water applications.
The gold layer is very thin and adds only a few cents per magnet.

 Gold Superior Good Superior Superior Superior Superior 10-20 Microns High
Plastic

Plastic is the most corrosion resistant. However its is thicker than other platings. A mold is required to create the plastic shell.

 Plastic Superior Superior Superior Superior Superior Superior 250-500 Microns Medium
Phosphate

Phosphate is a temporary coating that will last only a few months. It is normally used when the magnet is going to be over-molded or encased in a plastic part that will act as the final protective layer.

 Phosphate Good
(Temp)
Bad Bad Bad Bad Bad 1-2
Microns
Low

Surface-Treatments-On-Compression-NdFeB-Magnet