All of the English coins that were issued prior to the reign of Queen Elizabeth were hammer struck. During Elizabeth's reign Frenchman, Eloye Mestrelle, was allowed to set up a mint and produce milled coins with a screw press staring in 1561. The screw press was powered by human labor or horses. The resulting coins were much better than their hammered counterparts, but Mestrelle run into technical problems that made his coining process slow and expensive. His machinery frequently broke down. Maestrelle was eased out of his job in 1572. Six years later he was caught making counterfeit coins and was hanged. Here are examples of a hammered and a milled sixpence. Hammered Milled This coin is one of the most Elizabeth I milled pieces.