In the Ancient World, everything was made by hand, including coins that were minted in the millions using very simple tools. Coins were sometimes produced by casting in a mould, but this process was only usual for large pieces. The common method was to strike them with a hammer.
The basic tools for coin production were a furnace for heating the blank metal discs or "flans", tongs for handling them, a bench on which an anvil was mounted, and a pair of dies struck with a heavy hammer to impress the design into the flan.
The dies were produced of hard bronze or iron and contained an inverse version of the image to be struck on each side of the coin. They were engraved by skilled artisans known as engravers.
Teams of at least three workers were involved in the minting process. Using tongs, one worker would bring the flan from the furnace, another would hold the upper die in place and a third would strike it with the hammer. By repeating this process, an experienced team of workers could produce thousands of coins in a day and Roman mints had generally several teams working side-by-side fulltime. The high frequency of misstruck coins indicates that minting teams worked at very high speed.
As a result of this process, each ancient coin is unique.