How are pennies made?
Pennies are made in a coin factory called a mint. To make pennies, a machine cuts round coins form a long metal sheet about as thick as the finished coin. These round coins are called “blank” because they have no pictures on them. Each blank then goes into another machine that makes a raised rim around the edge.
Next, the penny blanks go into a stamping press that stamps a picture on each side of the penny. Nickels, dimes, quarters, half dollars and “silver” dollars are made in much the same way.
In making coins, the stamping press also squeezes ridge on the rims. In the early days these coins were made mostly of silver. People sometimes cheated by scraping a little of the valuable silver off the edge of the coins.
The coin makers put ridges on the coins so that people could easily tell when coins had been trimmed or scraped. When pennies and the other coins become worn or damaged, they are collected and sent back to the mint, which remelts them and makes new coins. – Dick Rogers