Coin magnetism often sparks curiosity, as most everyday currency does not react to a magnet. While the majority of coins in circulation are non-magnetic, certain denominations from various countries do exhibit this interesting property. This magnetic behavior stems directly from the specific metallic compositions chosen during minting. Understanding which coins are magnetic and why reveals insights into coin production and material science.
Coins That Attract Magnets
Several countries have issued coins that are attracted to magnets, often due to changes in their metallic composition. In the United Kingdom, for instance, 1p and 2p coins minted since 1992 are magnetic because they are made of copper-plated steel, a change from their previous bronze composition. Similarly, UK 5p and 10p coins issued after January 2012 are also magnetic, being composed of nickel-plated steel. Canada has also produced magnetic coins, including some steel-core pennies and many nickels (five-cent pieces) made from nickel or nickel-plated steel.
In the United States, the most notable magnetic coin is the 1943 steel cent, produced during World War II due to copper shortages for the war effort. This penny is among US coins for its magnetic properties. Eurozone countries also have magnetic coins; the 1, 2, and 5 cent denominations are highly magnetic, while the inner part of 1 and 2 Euro coins shows slight magnetism. Other countries like India and South Africa have also issued steel-based coins that exhibit magnetic properties.
The Materials That Make Coins Magnetic
A coin’s ability to attract a magnet depends on the type of metal it contains, specifically ferromagnetic materials. Ferromagnetism is a property of certain materials, primarily metals like iron, nickel, and cobalt, that are strongly attracted to magnets. Steel, an alloy mainly composed of iron, is the most common ferromagnetic material in magnetic coins. The iron content within the steel core makes these coins magnetic.
Conversely, many commonly used coin metals are non-magnetic. These include copper, brass, bronze, silver, gold, aluminum, and zinc. These metals lack the specific atomic structure necessary for strong magnetic attraction. Therefore, coins made predominantly from these materials will not stick to a magnet.
How to Test Coins for Magnetism
Testing coins for magnetism is a straightforward home process. A common household magnet, such as a refrigerator magnet, is sufficient. Simply hold the magnet close to the coin or place the coin on a flat surface and bring the magnet near it.
If the coin contains ferromagnetic metals, it will be attracted to the magnet and stick to it. A strong attraction indicates magnetic materials like steel or nickel. If the coin does not stick or shows only a very weak interaction, it is likely made of non-magnetic metals.