The 1955 US penny is made of copper, not tin. It's important to note that:
* Pennies have always been made of copper, except for a short period during World War II when they were made of steel. This was due to copper being needed for the war effort.
* Pennies minted after 1982 are a copper-plated zinc core, but the copper plating is still significant.
If you have a penny that looks like it's made of tin, it might be:
* A replica: There are many replica coins made of various materials, including tin.
* A foreign coin: There are coins from other countries that resemble US pennies but might be made of different metals.
Let me know if you have any other questions about US currency!
