Most magnets are glued/ assemblied with glue, like loctite 326, AB glue, or epoxy sealed, so there's a important technical data-Dyne should be focused.
In my experience, the Zn coating is the easiest coating to glue,the NiCuNi/epoxy is less, while I notice it, I learned some knowledge of the coating, and I found dyne data is important to inspect when I finish a coating. I choosed several dyne pen, US ACCU/A.Shine, Germany Arcotest, England Pilla, the data is 36~38, if the coating is fitable in the range, then the magnets are easy to glue, otherwise you should be careful with the coating, sometimes even you glue the magnet but there's big risk to escape from the parts.
