Coin Minting Robot: From Hammer and Die to ABB Arms

A coin minting robot works in one of the oldest factories there is. Mints have struck metal between two dies for more than two thousand years, and the press still works on that idea. The handling around it has changed a great deal, from feeding blanks and changing dies to counting and packing the finished coins. This post follows that work from hand hammered coins and the screw press to Matthew Boulton's steam mint of 1788, then looks at the robots now working in national mints, the end of the US penny, and where ABB robots could fit in coin production.

A press operator seated beside a large flywheel coin press, from the US National Archives. Photo: NARA via Wikimedia Commons (public domain)

How mints struck coins by hammer, screw and steam

For most of history a coin was made by hand. A worker placed a weighed blank, called a planchet or flan, on a lower die known as the pile, which was set into a heavy block such as a log. He held the upper die, the trussel, on top and struck it with a hammer, printing both faces at once. Hammered coins were often off centre and uneven in shape. England kept making them long after machines appeared on the continent, and hammered production there only ended in 1662. Venice kept hammering coins until the 1770s.

Both faces of a silver coin of Charles I, dated 1633, recorded by the Portable Antiquities Scheme. Photo: The Portable Antiquities Scheme / Wikimedia Commons (CC BY-SA 2.0)

Machines came first as screw presses. A blank sat between the dies, and workers swung a long arm with heavy weights on its ends to drive a screw down onto the upper die. Pressure replaced the hammer blow, so coins came out rounder and more even. The first non hammered English coins were made under Elizabeth I in the 1560s, and France became the first country to switch fully to machine made coins in 1643. Screw presses of this kind, called balanciers in French, can still be seen at the Monnaie de Paris museum.

A balancier screw press from 1775 in the Musee de la Monnaie de Paris. Photo: Chatsam / Wikimedia Commons (CC BY-SA 3.0)

Steam took the next step. In 1788 Matthew Boulton set up the Soho Mint near Birmingham with eight presses of his own patent design, driven by a steam engine, each striking 70 to 85 coins a minute. Coins were struck inside a collar so their diameter, thickness and weight could be checked. In 1797 Soho made Britain's first penny coins, the cartwheel pennies, and struck over 45 million in two years. Robots arrived much later. The US Mint at San Francisco installed a robotic packaging line in 2010 that raised proof set output from about 600 to about 1,800 an hour.

Coining presses at the US Mint in Philadelphia on a Keystone View Company stereograph. Photo: Library Company of Philadelphia via Wikimedia Commons (no known restrictions)

Robot arms in the die shops and packing rooms of national mints

Coin production is in the news in the United States. The US Mint stopped making pennies in 2025, and on 29 September 2026 the AP reported that Congress had sent the Common Cents Act to President Trump. The House passed it on 14 September and the Senate followed by voice vote. The bill ends penny production after 234 years and rounds cash transactions to the nearest five cents. The Mint says each penny cost close to four cents to make and that stopping would save about $56 million a year. Pennies stay legal tender.

The entrance to the Royal Mint at Llantrisant in Wales, 2017. Photo: M J Roscoe / Wikimedia Commons (CC BY-SA 2.0)

Inside mints, robots do the repetitive handling around the press. At the Denver Mint die shop, robot arms carry die blanks from the cutting lathe to a polishing machine and move shaped dies between lathes and conveyors. At San Francisco, a loop of yellow robots places proof coins into card inserts and plastic lenses, picking each coin with suction at the arm tip so no one touches its surface. Swissmint uses three FANUC robots to pick coin rolls ten at a time, fold boxes and stack pallets. A die vision system from Newton Labs checks that the right pair of dies sits in a press before it runs.

The new generation ABB IRB 1200, a compact arm for machine tending and small parts. Photo: ABB

ABB is not named in any of these mint projects, so this part describes a possibility. A compact arm such as the new IRB 1200 suits press tending: loading blanks, removing struck pieces and swapping small steel dies. An IRB 360 FlexPicker with PickMaster software could pick coins or rolls from a moving belt using conveyor tracking, and IRB 460 or IRB 660 palletizers could stack heavy boxes of rolls and bags at the end of the line. Coin presses are smaller than the car body presses in our post on press line stamping, but the tending ideas carry over.

ABB IRB 360 FlexPicker robots packing small items at high speed. Photo: ABB

Where coin minting robots go next

The job mix in mints is changing. Losing the penny takes away the highest volume US coin, while collector coins keep coming. In September 2026 the Royal Mint released Star Trek 50p coins, then a Wicked 50p and Cluedo 50p coins, and in August its first 10p coins with King Charles III entered circulation. Collector runs are short, with many designs and finishes, and every die change is a chance to damage a die or a coin. That favours flexible robot cells that can be reprogrammed quickly over fixed transfer machines built for one coin.

Rolls of US coins by denomination, from pennies to quarters. Photo: ThienDe98 / Wikimedia Commons (CC BY-SA 4.0)

The open problems are particular to mints. Security comes first: a cell that handles gold and silver blanks has to count every piece and log every move, and a robot can make that record automatically. Proof coins are easily marked, so grippers need soft or suction contact and tight control of speed. Cost is the other hurdle, because a mint may strike some products only a few weeks a year. Staff skills matter too. Press operators who know the dies are the people best placed to program and maintain robot cells, if they get the training.

An ABB IRB 660 palletizer stacking boxes at the end of a line. Photo: ABB

Most robot cells for jobs like these are now laid out and tested first in RobotStudio, which lets a mint check reach, cycle time and guarding before buying hardware. A dual arm robot such as ABB's YuMi, built for small part assembly next to people, could in principle assemble proof sets in a small run. The press in such a cell would still squeeze a blank between two dies, as Boulton's presses did at Soho. The robots would take the blank to it and carry the coin away to a sealed box.

ABB YuMi assembling small parts beside a lab worker. Photo: ABB

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