How Are Coins Made?

How Are Coins Made?

Coins are made using a manufacturing process called Minting (also called coining or coinage).

Before coins are imprinted by dies in the coining process, unmarked coins are known as blanks. A blank must undergo many steps before a design is committed to the surface.

Modern coins are minted with hydraulic coining presses that automatically feed the blanks into the machine. When the machine is running at full capacity, the press can make over 600 coins per minute!! This speed is necessary for an operation like the United States Mint, which must produce billions of coins every year.

The minting process begins with the mining of raw materials. Mines from across the United States and worldwide supply gold, silver, copper, or other required metals. The raw metal obtained from these mines contains impurities that are not acceptable for coinage.

The raw metal is then refined to remove almost all impurities. Once the appropriate purity or alloy is achieved, the metal is cast into an ingot.

The process of rolling the ingot to the proper thickness can be long and laborious. The ingot is rolled between two hardened steel rollers that are continuously moving closer and closer together. This process will continue until the ingot is rolled into a metal strip that is the proper thickness for the coin being made. Additionally, the rolling process softens the metal and changes the molecular structure which allows it to be struck easier and produces higher quality coins.

It is then passed through a machine that punches out discs of metal that are now the proper thickness and diameter for the coin being made.

The mint then passes the coin blanks through in the annealing oven to soften the metal in preparation for striking. The blanks are then put through a chemical bath to remove any oil and dirt that may be on the surface of the coin. 

To protect the design that’s going to be impressed on the metal coin blank, each coin blank is passed through a machine that has a set of rollers that get a little bit smaller and imparts a raised metal rim on both sides of the coin blank. This process also helps ensure that the coin blank is the proper diameter so it will strike up properly in the coining press. After this process, the coin blank is now called a planchet.

Now that the planchets have been properly prepared, softened, and cleaned, they are now ready for striking. Business struck coins are automatically fed into the coining press at a rate that can reach several hundred coins per minute. Proof coins made for collectors are fed by hand into the coining press and receive at least two strikes per coin.

Coins that pass inspection are now ready for distribution. Business struck coins are packed into bulk storage bags and shipped to The Federal Reserve Bank for distribution to local banks. Collector coins are placed in special holders and boxes and shipped to coin collectors around the world.