Attraction between unlike magnetic poles. Clumping of iron filings in the presence of the magnetic field produced the two horseshoe magnets with their unlike poles aligned (labelled N, north, and S, south). This results in magnetic attraction. The magnetised iron filings align due to the interactions between them, even though the magnetic field itself is continuous. Magnetism is a property of ferromagnetic metals (such as iron, nickel and cobalt) caused by the alignment of the spins of the electrons in the metal.