How Coins are Made

When did milling begin and how did ancient criminals profit from it?

Today, our currency is pressed out of long sheets of metal and stamped under pressures of up to 360 tons per square inch in automated machines. But before Matthew Boulton’s steam-powered minting process and Peter Blondeau’s hand-cranked machinery, coins were struck individually by hand.

Carefully weighed circular blanks of metal from the forge were placed between two hardened metal blocks, one with the reverse design and the obverse design on the other. The top die was then struck hard with a hammer so that the softer metal of the coin blank took on the design on both sides.

The process – which was called milling-was comparatively time-consuming and was also fraught with errors: coins were frequently struck off-centre, double-struck or cracked.

Check also – Ancient coins  and Department of Coins and Medals

Worse still for the authorities, because gold and silver were used in the higher denominations and because no two coins were alike, the act of ‘clipping’ the edges of precious metal coins, or ‘sweating’ silver coins (shaking a bag of silver and collecting the dust), was common practice among the unscrupulous, who could then profit by spending the coin at its face value while pocketing the precious remains.