Hammered coinage

Hammered coinage describes the commonest form of coins produced since the invention of coins in the first millennium BC until the early modern period of ca. the 15th-17th centuries.

Hammered coins were produced by placing a blank (a planchet or flan) piece of metal of the correct weight between two dies, and then striking the upper die with a hammer to produce the required image on both sides. In later history, in order to increase the production of coins, hammered coins were sometimes produced from strips of metal of the correct thickness, from which the coins were subsequently cut out. Both methods of producing hammered coins meant that it was difficult to produce coins of a regular diameter, and coins were liable to suffer from "clipping" where unscrupulous people would remove slivers of precious metal since it was difficult to determine the correct diameter of the coin, or "sweating" when silver coins would be placed in a bag which would be vigorously shaken so that silver dust would be produced which could later be removed from the bag.

In England the first non-hammered coins were produced in the reign of Queen Elizabeth I in the 1560s, but while machine-produced coins were experimentally produced at intervals over the next century, the production of hammered coins did not finally end until 1662.

An alternative method of producing early coins, particularly found in Asia, especially in China, was to cast coins using moulds. This method of coin production continued in China into the nineteenth century. Up to a couple of dozen coins could be produced at one time from a single mould, when a 'tree' of coins (which often contained features such as a square hole in the centre) would be produced and the individual coins (called cash) would then be broken off.