Abstract: A magnetic fastener has a fastening element N having a strong ferromagnetic component 20 placed on the magnetic pole 10b of the permanent magnet 10. The magnet 10 has a hole 11 extend in the direction of magnetic field. The Fastener also has an element to be attracted M having a strong ferromagnetic component 50. The ferromagnetic component 50 will be pulled to the other side 10a of the permanent magnet 10 on the fastening element N. The element to be attracted M can also be designed in such a way that the fastening element N snaps on and off through the hole 11. At least one of the ferromagnetic components 20 and 50 protrudes beyond the circumference of the permanent magnet 10 for more than 0.1 mm but no more than 2.0 mm, when the diameter of the permanent magnet is 18 mm.