Why are coins milled

Also, on the eight reales denomination the design of the crown on top of the left pillar was changed in Prior to that time both crowns were identical, representing the royal Spanish crown. In the left crown was changed to the Imperial design.

Once again, in the Spanish government reformed their coinage. This time the weight remained the same but the fineness of the silver was lowered to. In order that coins made at the new standard could be identified from the earlier pillar coins the design was modified. The reverse was also modified. REX King of Spain and the Indies followed by the mintmark, the denomination and the assayer's initials. The corded edge of the eight reales was also replaced with an edge design comprised of alternating circles and rectangles.

These coins, which continued to be minted through , are known as the "portrait" or "modified pillar" series. The result was a coin that was of significantly higher quality making them much more difficult to counterfeit. They were also very circular so that it was obvious when clipping occurred. The French techniques and some of the French engineers made their way to England and the new milled process began to be adapted.

Hammered coins were eventually demonetized in As the Industrial Revolution took hold in Britain during the 18th century, workers moved from the rural areas to work in factories in the towns, and their payment was in coins. Britain required a considerable amount of low denomination coins to be in circulation. Steam-powered machines would eventually provide the solution to this. Matthew Boulton continued to make coins with this method until the Royal Mint was set up with steam machines and moved from the Tower Mint in Coins are made by the same method today, except steam engines have been replaced by electric motors.

After the Restoration returned Charles II to the throne, he recalled Blondeau from France, and awarded him a year contract to develop and apply methods for making milled and engrained edges. The contract for turning out blanks and stamping fell to three Flemish brothers, John, Joseph, and Phillip Roettier.

In the Tower mint produced a one-pound coin that signaled the beginning of mechanized minting in England. Methods for minting coins with the serrulated or corrugated edge also passed from France to Spain. In the English colonies and early United States, the Spanish milled dollar was among the most popular and widely circulated coins, passing as legal tender for brief periods. The Spanish milled dollar established the dollar as the principal unit of currency in the United States.

The practice of milled-edge coinage continues to the present day. In the United States, coins in denominations larger than a nickel have milled edges.