This rubber coated neodymium mounting magnet has an external stud with male thread.
These rubber coated neodymium magnets are very strong and high tolerance to metal strike and water penetration relative to non rubber-coated magnets. The male thread external stud can be trimmed if necessary. These high strength rare earth magnets are designed to be used with a washer and nut.
This is a document of products models regarding this pot magnet type.
products models_rubber coated pot magnet with external thread.pdf