The following is a list and description of common plating options for custom magnets.Why do magnets need to be plated?
NdFeB magnets will oxidize(rust) if left exposed. When a plating wears down or cracks, the exposed area will oxidize. An oxidized area will not result in complete degradation of the magnet, only the oxidized area will lose its strength. However the magnet will lose some structural integrity and become more susceptible to breakage.
Depending on shape, permanent magnet substrate is brittle. A multilayered metal plating like nickel or zinc improves the magnets resistance to chipping and wear, particularly around corners.
Platings vary in their tolerance of different harsh chemicals and abrasion. Salt and humidity in regions near the ocean are commonly overlooked when selecting a plating. Be sure to consider the magnets environment when selecting a plating.
The most common type of plating for neodymium magnets Nickel (Ni-Cu-Ni) Intended for indoor use. It has proven to be very resilient when subjected to normal wear and tear. However it will corrode oudoors in prolonged exposure to salt water, salty air, or harsh chemicals.
Industrial standard, good work stability, sufficient protection against corrosion in dry ambients, possible allergic reaction on sensible persons