How Were Coins Made Before Machines? Hammering Metal Between Two Stamps

Striking a coin requires a blank of metal of controlled weight and two dies carrying the designs in reverse. The lower die is fixed in an anvil and the upper is held by hand or in a holder, the blank is placed between them, and the upper die is struck with a hammer, which forces the metal to flow into the engraved recesses of both dies simultaneously. The blank must be soft enough to flow, which frequently meant heating it. One blow was usual and a second risked doubling the image if the die shifted. The whole operation needed at least two people and produced a coin every few seconds, which is why ancient mints could supply enormous quantities despite the method being entirely manual.

Characteristics of hand-struck coinage all trace to the method:

• •Irregular outlines, since blanks were cast or cut rather than punched precisely
• •Off-centre designs, where the blank was not placed accurately
• •Varying relationship between the two faces, since the upper die could sit at any rotation
• •Cracks radiating from the edge where metal was forced outward
• •Progressive deterioration, with later strikes from a worn die showing degraded detail
• •Die breaks appearing as raised lines across the coin, which are permanent from that point on

Because each die is individually engraved and wears distinctively, coins can be matched to the exact die that struck them, and that makes an unusual kind of reconstruction possible. Grouping surviving coins by die establishes how many dies were used for an issue, and statistical methods estimate how many existed originally from how many appear in a sample, which gives an estimate of the total coinage produced, since the number of coins a die could strike before failing is known approximately from experiment. Linking obverse and reverse dies that appear together establishes the sequence in which they were used and therefore the order of an issue. Progressive damage to a single die orders coins within that sequence precisely, which is a chronology finer than any other source supplies.

The die is only half the question, since what matters to anybody using a coin is what it contains. Reducing the precious metal content while keeping the face value is debasement, and it was done repeatedly by authorities needing revenue, since the difference between the metal cost and the face value is profit. The consequences follow predictably, with prices rising, with good coin being hoarded or melted while bad coin circulates, which is the observation named after Thomas Gresham though it was noted long before him, and with confidence in the currency falling. Analysis of surviving coins measures debasement directly and has reconstructed fiscal crises in several periods that written sources describe only vaguely, which is among the more useful things numismatics supplies to history.

Mechanisation arrived gradually and changed what a coin could be. Screw presses, applied to coining from the sixteenth century, deliver a controlled and far greater force through a heavy screw, producing uniform well-centred coins with consistent relief, and they allowed edge lettering and milling, which addressed the persistent problem of people shaving metal from the edges of hammered coins. Adoption was slow and contested, partly because the machinery was expensive and partly because mint workers resisted it. Roller presses and then steam-powered presses followed. The final transition in England came in 1662, after which hammered coin was withdrawn, and the resulting uniformity is why modern coins look as they do and why a hammered coin is instantly recognisable.

A blank is struck between a fixed lower die and a hand-held upper one, which explains the irregular outlines, off-centre designs and varying alignment of hand-struck coinage. Each die wears distinctively, so coins can be matched to the die that made them, which estimates how much was produced and orders an issue precisely. Screw presses allowed edge milling, which stopped people shaving the edges.