China Neodymium And Ferrite Magnets Manufacturer & Supplier 
Black nickel magnets, most people should not have seen, including some not long into the magnet counterparts, because this plating is not a conventional plating, only a small number of customers will ask to do this kind of plating.
Black nickel magnet appearance picture
*Black epoxy Black nickel Surface color comparison of nickel *
The magnet in the middle of the picture above is the NdFeB surface treated with black nickel plating, which has a charcoal or bronze colored shiny appearance. Black dye is added in the final nickel plating process of three times nickel-copper-black nickel plating, which is not completely black like epoxy resin coating, but still has a glossy appearance, very much like ordinary nickel-plated magnets.
NOTE: Selection of different coatings will not affect the magnetic strength or performance of the magnet, with the exception of plastic and rubber coated magnets, where the preferred coating is determined by the preferred or intended application.
Black nickel neodymium magnet products;
Black nickel coated countersunk magnet ring 17 x 5.8 x 9 mm
More magnet coating introductions;
How to remove the surface coating (plating) of a magnet?
Difference between nickel and chrome plating of magnets
How many hours of neodymium magnet nickel plating salt spray?