Plating and Coating: As un-coated NdFeB magnets are sensitive to outer air and temperature,so if expose the un-coated NdFeB magnets in the air for some time,the Surface of magnets will turn to be rusted easily and quickly.That is the reason why we need to coat the magnets with Diffferent plating ,such as Nickel,Cr3+Zn.Black Epoxy etc.
For more informations,please visit the coating of NdFeB magnets below: Magnets coating plating