The science bit: Since 1992, 1ps and 2ps have been made out of copper-plated steel instead of the previous alloy of copper, tin and zinc. Steel is magnetic so
Coins are made of different materials, which is why some are magnetic, and others aren't. The most common metal in coins is copper, which is not magnetic. Other metals commonly used in coins, such as aluminum and nickel, are not magnetic. However, some coins do contain magnetic metals such as iron and steel.
If you have a strong enough magnetic field all matter is magnetic. But copper is so weakly magnetic that we can't observe it without very, very large magnetic fields. So the short answer is "No, copper isn't magnetic." This can quickly be tested by trying to pick up a penny with a magnet.
The penny, nickel, and aluminum foil ball are not magnetic.
If it sticks to the magnet, it is steel, but still worth anywhere between 20 cents and $20. However, if it doesn't stick to the magnet, you might be in for a windfall. Of course, the 1943 copper penny isn't the only coin worth a lot.
Since 1992, 1ps and 2ps have been made out of copper-plated steel instead of the previous alloy of copper, tin and zinc. Steel is magnetic so pennies made after 1992 will be attracted to the magnet when it is close to them. Pennies made before this will not be magnetic.
The 1943 steel cent is the only regular-issue United States coin that contains enough iron to be magnetic. While nickel is also magnetic, there isn't enough nickel in standard United States coins to make them magnetic.
Copper-plated coins are attracted to magnets because of the iron content of the steel core, whereas bronze coins are not magnetic.
Metals That Don't Attract Magnets
Certain metals in their natural states such as aluminium, copper, brass, lead gold, and silver don't attract magnets due to the fact they are weak metals. However, properties including iron and steel can be added to these metals in order to make them magnetic.
The metal detector does not know what is a coin, Gold ring, foil, etc. It identifies all targets based on their conductivity. For example: Most foil has a low conductivity, Ring pulls, and certain coins have a mid-conductivity and most large coins have a high conductivity.
A steel penny is the only one that will stick to the magnet. Here's the magic part (drumroll please). If a penny sticks to the magnet, check the date. A 1943 circulated penny that sticks is worth 10 cents or so.
Pennies are made of zinc coated with copper. Only nickels are one solid material—that same 75% copper/25% nickel alloy.
If the coin sticks to the magnet, it's made of steel and worth about 10 cents. If the penny does not stick to the magnet, you've got one.
10, 20 and 50 cent coins: They have no magnetic properties.
If your 1943 penny is made out of copper, it is worth quite a bit of money, generally $10,000 or more! The reason is that the 1943 copper penny is an error coin. The United States Mint accidentally used the wrong planchet metal when striking the coin. But very, very few of these left the U.S. Mint facilities.
An Extremely Fine coin with traces of mint red might be worth $20, almost uncirculated coins worth perhaps $50-$75. A full red uncirculated 1943 penny from the Melbourne, Perth, or Bombay Mint is worth up to $250.
While the 1943 wheat penny error is extremely valuable, it is important to note that it is also very rare. Among these errors are several versions—the bronze planchet 1943-D, the 1943-S, and the 1943 Philadelphia, un-minted version. The 1943-D bronze planchet is the most valuable, as only one known copy exists.
The 1959-D wheat penny is one of the most controversial mule coins ever. It's worth $50,000! Here's everything you could possibly want to know about the 1959-D penny error!