Are there single-layer nickel plated magnets?

Yes, Nd-Fe-B double-layer nickel (nickel copper nickel) is actually an improvement on the early single-layer nickel, but it was gradually replaced by nickel copper nickel in the late 1990s. Now magnet manufacturers are basically plating NiCuNi.

In the early days, Nd-Fe-B nickel plating was generally single-layer nickel plating. The porosity of nickel coating is high, and it is a typical cathodic coating at this time. Therefore, unless the coating is very thick (up to 20 ~ 25um), it can not protect NdFeB matrix, but accelerate its corrosion. Rolling nickel plating is not easy to be thick, and too thick nickel layer (because nickel is a ferromagnetic metal) will seriously affect the magnetic properties of Nd-Fe-B magnet. Therefore, NdFeB single-layer nickel plating is not an ideal choice. At present, only a few products with low anti-corrosion requirements are still plating single-layer nickel, and most of the other NdFeB nickel plating are using multi-layer coating combination.

PS: the corrosion resistance of double-layer nickel is better than that of single-layer nickel, so nickel copper nickel is recommended, which has better appearance and cheaper price.