As part of permanent magnetic motor or generator, magnetic rotor consist of iron part and permanent magnet.
Because the development of magnetized technology, some common magnet rotor can be magnetized after magnets are mounted on the iron ring. But for some special magnetic rotor , the magnets have to magnetized at first , then they will be glued onto iron ring by special tools by experienced staff.
Because same pole will be repel each other, it very difficult to glue them together. If you interesting in such items ,please do not hesitate to tell me.