This alignment is damaged over time, principally as the result of heat and stray electromagnetic fields, and this weakens the level of magnetism. The process is very slow, however: a modern samarium-cobalt magnet takes around 700 years to lose half its strength.
Also question is, how does a magnet loses its magnetism?
Yes, it is possible for a permanent magnet to lose its magnetism. There are three common ways for this to occur: 1) Via heat: ferromagnet materials will lose their magnetism if heated above a point known as the Curie temperature. Modern materials do not suffer this type of problem.
Do magnets run out of magnetism?
It would make sense that a magnet would operate like a battery and would run out of power. Actually, it turns out that magnets don't operate like batteries. A magnet works by the atoms lining up in a piece of iron or steel. When the atoms are aligned, north and south poles are created, resulting in magnetism.