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How are circulated and collected coins made?

I will tell you about the process to make those nice coins that you would like to have in your collection.

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Cómo se hacen las monedas que circulan o se coleccionan

I too wondered how coins are made when I was getting into the world of coin collecting. That’s why it’s strange that I haven’t written this text until now.

But it is never too late if the information is good. Therefore, in this article we are going to review how the coins that circulate in your hands, and possibly you want to collect, are made.

This process may differ somewhat depending on the countries, and the different technologies available to the mints. However, the essence of the coin creation process is quite similar, so read carefully, but emphasize the general lines.

By the end of the text, you will be able to tell everyone how a coin is made. Starting from being a simple idea in the head of a designer, to becoming a valuable piece of metal that you carry in your favorite pocket or purse.

Coin design

If there is one thing that stands out on many coins, it is the design. In fact, in my opinion, this is one of the elements of coins to which most attention is paid, and not in vain. Many coins are true works of art, both for their aesthetic and symbolic values.

Therefore, it is best to begin this article on the manufacturing process of a coin with the stage that starts everything else.

Normally, coin designs respond to motifs of interest and significance to the people of the country where the coin is to circulate. In some cases, the designs may be inspired by extraterritorial and global motifs. What is a constant is that they must be events, people or symbols recognized and valued by a large number of people.

Diseño informatico de moneda Bullion canadiense
Image source: Discovey MAX.

This gives us an infinite list of possible motifs from which the person designing a coin can draw inspiration.

Artists use design software to translate their ideas into a digital model, which they can share with those responsible for approving it. The approval of a coin may be given by a committee of experts, the country’s presidency, or the directors of the corresponding mint. Each country and each case may be different.

Once the design is approved, the model is materialized in a plaster disc 27 centimeters (10.5 inches) in diameter. This is a rather large size compared to the dimensions that future coins will have later on.

Disco de escayola modelo a escala de la futura moneda
Image source: Discovey MAX.

The justification for creating such a large coin model is that the artists designing the coin can retouch the details by hand. In this way, a perfect scale model remains.

Once the plaster coin model is ready, another new mold is created, but this time in negative. Again another positive mold (with relief) is generated, but this time in rubber, and from this last one another negative mold is created, but using black epoxy resin. This last mold is quite rigid compared to the other coin models.

The rigid resin model is placed in a machine called a pantograph which is responsible for reproducing on a smaller scale the original mold, but this time on a piece of brass. Many people know the pantograph as a “reduction machine”, since its function is to generate a new mold, but one and a half times smaller in brass.

Again, the details of the design of this negative model are revised and retouched.

Persona repasando detalles del diseño de monedas
Image source: Discovey MAX.

Normally in this step of the process some essential elements are added, such as the year, the value and the country of issue. In many cases, legends and even the mint mark are added.

For the second time, the design is subjected to a reduction process to generate another negative mold, but this time it is stamped on a higher quality steel and the final size of the coin. This is known as “the die”. If you think there have been too many design transfers, get ready, because there are still two more to go.

The steel die is hammered into the die against a steel block to create a new positive die called a die-sinking punch. Finally, by striking the punch against another block of steel, the dies are created with which the coins will later be minted.

Preparation of coin blanks for minting coins

In addition to the dies, the mint needs to have round pieces of metal ready to become coins, known as coin blanks. A coin blank is to a coin as a block of marble is to a Michelangelo sculpture.

How do you prepare a coin blank to mint a coin on it? Let me explain.

The staff of the mint takes a large amount of gold, silver or other metal in which the coins will be made, and places it in a melting furnace that reaches a heat of 1,150 degrees Celsius (2,102 degrees Fahrenheit).

Horno para fundir metales para monedas
Image source: Discovey MAX.

The molten metal is cast in the form of a continuous bar approximately 4 centimeters (1.5 inches) high and 12 centimeters (almost 5 inches) wide. This bar is cut into individual ingots 80 centimeters (31 inches) long.

The ingots are passed several times through a grinding mill that progressively flattens the ingot. The machine has 2 rollers that apply 8 metric tons of force on the metal. To achieve the correct measurements before moving on to the next step, the ingots must pass through the mill up to 12 times. The result is a strip of metal 12 millimeters (1/2 inch) thick.

The next machine used is a rolling mill, through which the metal sheets are passed until they are the exact thickness of the coin to be manufactured. The metal sheet is introduced into a die cutter that cuts and extracts the coin blanks.

A very important fact is that in coin manufacturing nothing is wasted. When the blanks are punched out, the excess silver, gold or other metal is melted down again to repeat the process I just described.

Now we have a beautiful design, several dies made from it, and a bunch of blanks almost ready to be transformed into beautiful coins.

But first…

Preparing the blanks to be minted.

Ever wondered how some coins have such perfect finishes, where you can almost see yourself as if in a mirror? Well, it’s possible thanks to the process I’m about to tell you about.

The newly created coin blanks are introduced into a new machine that creates a raised edge known as a rim, near the edge of the coin. This process is done by applying great pressure on the metal parts.

Máquina cortando cospeles de la barra de metal
Image source: Discovey MAX.

The coin blanks are then placed in a bathtub filled with water, certain cleaning chemicals and steel balls. Yes, steel balls. These balls are in charge of smoothing and polishing the coin blanks to that finish I told you about before.

The polished coin blanks are removed by hand by the mint operators. They are then dried by hand using cloths prepared for this purpose.

The process must be done by hand to ensure that no water stains remain on the surface of the metal parts. Otherwise, these stains would persist later on, making the resulting coins unsightly.

Some metals, such as silver, tend to weaken while undergoing all these steps. To prevent cracking, the coin blanks are passed through an annealing furnace at different stages of the process. The annealing restructures the silver molecularly, and makes the blanks stronger.

Now we have blanks ready to make the beautiful coins that collectors love. For which they sometimes pay a lot of money.

Coin minting and preparation for sale

The process of making coins for circulation is quite industrial. That is, the coin blanks are struck in a press, with the dies stamping the design on the metal and the coins are ready to be used.

In contrast, PROOF and commemorative coins, designed and minted for collectors, follow a slightly different process.

These commemorative coins are produced one at a time in the press, placing each coin blank manually in the press, and striking the metal piece twice to achieve a high quality impression. This is very characteristic of this type of coins.

Another important detail is that the coin blanks and dies are treated with different chemical products that enhance the polish and quality of the coins.

Persona acuñando manualmente monedas PROOF
Image source: Discovey MAX.

Once minted, the pieces undergo quality control to ensure that everything is correct. However, even with all the measures designed, sometimes errors occur that are not detected in time, and the coins end up going on sale. When something like this happens, but the number of coins with errors is small, collectors lose their minds to get those rare coins.

A recent example of this is what happened recently with the Lithuanian 2 euro coins. An error at the mint allowed the minting of Lithuanian coins, but in the wrong coin blanks. Once the error became known the coin skyrocketed in value to the thousands of dollars. You can read more about this in the article Error in 2 euros of Lithuania 2021 shoots its value to the sky.

Although I should point out that this situation happens very rarely.

Most of the time there are no guarantees that the manufactured coins become a coveted collector’s item.

Conclusions

I hope this article will help you to understand the process of making a collector coin. As you read, there are many steps necessary to generate one of these small but valuable works of art.

If you liked the article leave me a rating by marking the stars below. You can also share the link in your social networks, so that other people can also know how to make the coins they carry in their pockets or purses.

Kossi Adzo is the editor and author of Startup.info. He is software engineer. Innovation, Businesses and companies are his passion. He filled several patents in IT & Communication technologies. He manages the technical operations at Startup.info.

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