JBF National neodymium diametric disc and cylinder magnets are crafted from the highest quality rare earth neodymium. These magnets are utilized across a wide spectrum of industries for a multitude of uses. To ensure longevity and maximum protection from corrosion, these magnets come triple coated with a base and top finish layer of nickel, with a layer of copper in between. Also, the holes these magnets feature make affixing them in place as needed, no issue at all.