An unmagnetized piece of iron can be magnetized by stroking it with a magnet. Another means is that if a piece of unmagnetized iron is placed near a strong permanent magnet, the iron becomes magnetized.

An iron magnet can remain magnetized for some time. However, if you drop a magnet on the floor as in the previous activity or strike it with a hammer, the vibration may cause the domains into randomness. The magnet can thus lose some or all of its magnetism. Heating a magnet too can demagnetize it, for raising the temperature increases the random motion of the atoms which tends to randomize the domains.