A mint is an industrial facility which manufactures coins for currency. The history of mints correlates closely with the history of coins. In the beginning, hammered coinage or cast coinage were the chief means of coin minting, with resulting production runs numbering as little as the hundreds or thousands. In modern mints, coin dies are manufactured in large numbers and planchets are made into milled coins by the billions. With the mass production of currency, the production cost is weighed when minting coins. For example, it costs the United States Mint much less than 25 cents to make a quarter, and the difference in production cost and face value (called seigniorage) helps fund the minting body.