VOCABULARY TERM: STRIKING

Striking. Forming relief objects by an impression with a pair of dies and the force of a press. Presses utilize two dies, one obverse, one reverse, to impart the design on both sides at once. The first press, used at the beginning of the 16th century, were screw presses. They were able to strike small thin coins and were powered by man, or more likely two men. Each pressed against a long bar that transferred the motion – by a transversal screw – a downward thrust of a housing containing one of the dies (usually the reverse, where the obverse die is fixed in the pile position below). Pressing creates the raised relief on both sides of the struck piece at one time.

The screw press was used for nearly 400 years. Its improvement came slowly at first, but as the presses were built stronger and with attachments to feed blanks and eject struck pieces, the striking improved. As power changed from man to horse to steam power, larger diameter pieces could be struck with greater depth of impression.

With the invention of the togle-joint press in 1816 greater control over the impression became possible. Each development of this press had an effect on its capability to strike a piece of greater diameter, thicker planchet, better surface control, sharper detail and edge treatments with a sharper rim/edge juncture.

Pre-preparation of the blank aided striking greatly – by upsetting – leading to automated coining, and, ultimately, high speed coining. This was further enhanced when electric motors were applied to coining presses.

Striking is one of five major methods of reproducing numismatic items, the others are casting, repoussé, niello, forged. While each of these has its own place, striking alone is the only method of manufacture suitable for coining – striking in a coin press – for high speed manufacture of highly detailed small disklike objects often of valuable metal.

History of striking. Coins made before the use of a press are known as hammered, formed with a sledge blow to a punch with a blank placed between it and the die in the pile position below, each imparting a design image. The coiners were moneyers who produced the hammered coins manually. These workers were so well entrenched that when the screw press was introduced (in 1551 in France, and 1561 in England) that the moneyers were able to thwart the continued use of the screw press for nearly a century.

Hammered coins, therefore, were not phased out until 1641 in France and 1662 in Great Britain. Thus the screw press, which was developed for coining in 1506 in Italy, was not fully in use elsewhere until more than 150 years later! Striking dates from this irresolute period of coining history.

Matthew Boulton did more to improve striking than any other individual in coining history. He not only applied the power from his steam engines, but also developed better blank preparation, upsetting, but also used the finest steel for dies he could obtain (from Benjamin Huntsman, who had developed crucible steel in 1756).

Diedrick Uhlhorn invented the togrel-joint coining press in Germany in 1816. This was improved upon by Eugene Thonnelier in France in 1836. Each of these presses struck coins with better striking control, higher quality and better relief surfaces than before. Their power derived from steam or water, transferred to the presses by belts.

The hydraulic press was invented about this same time, but it was too slow for coining, The togel-joint press gave a sharp blow for the impression in contrast to the squeeze of the hydraulic press.

For the last half of the 19th century the screw press and the togel-joint press were is use simultaneously. It was only when commercial electricity and electric motors became available and these were applied to run presses that it was learned that it was easier to electrify togel-joint presses than screw presses, that the later was phased out of coin production.

Thus the development of striking paralleled the development of presses and how they were powered. Striking improved by sharper images, in larger diameter coins, with dies that lasted for longer press runs. See presses and pressroom practice.

References:

C24 {1948} Mason.
NC6 {1960} Peck, p 141, note 1.

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