The result is that the plating lasts many times longer than it would if the coins were plated after striking. Steel is magnetic, bronze and silver are not magnetic. So if you have a copper or silver coloured penny which is magnetic, it cannot be silver or bronze, it must be made of steel. Similarly, if it is non-magnetic, it is made of steel or bronze. It is easy to tell silver from bronze because they are different colours.
Most modern refrigerators have magnetic seals around the inside of their doors.
By holding your coins to the magnetic strip, you will easily be able to tell which is which. Many people already know this because they recycle aluminium cans. As refigerators are not easy to carry round in your pocket, if you wish to check your change while you out shopping, we suggest buying a pocket size magnet. For more information about them, you could take a look at our Silver Pennies in Change page. If you read our History of the Penny page, you can learn even more about pennies.