Hiroshima Branch

Three mints in three different parts of the country

Osaka, whose mint I had the privilege of visiting in 2024, is home to the headquarters of the Japan Mint, where decisions are made regarding themes, motifs, strategies, and all administrative details. Here you will find the creative department, responsible for the dies, as well as the enamel department, where the brightly colored medals – a specialty of the Japan Mint – are created.

The Saitama Mint, where I had the pleasure of visiting in 2023, is located near Tokyo. Its focus is on the production of commemorative coins and the state control of gold items. Here, the coveted hallmark is applied, guaranteeing the buyer the fineness of the gold.

Although circulating coins are produced in both Osaka and Saitama, the true center of production is located in Hiroshima. Shortly before the start of this year’s TICC, I made a detour there and learned a great deal. I had never before seen how a coil for circulating coins is made. It was fascinating! Join me on my tour of the Hiroshima Mint!

Alloy and casting

One thing I’ve learned during all my visits to the Japan Mint is that the Japanese are wonderful hosts. When they receive a guest, the entire operation prepares for their arrival. This was also true in Hiroshima. Every department had prepared something special for me to help me understand the technical processes. For example, Mr. Otani, Director of Melting Division, who was guiding me through the Melting Division, had a selection of the various raw materials used to create each alloy laid out right next to the entrance.

As the name suggests, the Melting Division does nothing other than melt metal to produce the specific alloys required for the various blanks. The end products of the Melting Division are massive ingots, which are subsequently further processed in the Rolling Division.

But first, I’m fascinated by the various raw materials, which arrive in different shapes and weights. I’m particularly impressed by a heavy block. At first, I can’t tell what it’s made of. Only upon closer inspection does it become clear: it’s made of finely cut, tightly folded punching grids, the kind left over after the blanks have been punched out.

This is very efficient and resource-saving. The waste from blank production goes directly back into the melt and can be processed back into coils without additional processes.

Now comes the part that impresses me the most! You can tell by the rising temperature: We’re approaching one of the two blast furnaces where the alloy for the blanks is alternately heated and mixed. I’m allowed to look into the boiling mass, but I have to hold a shield made of transparent protective material in front of my face, which I do gladly and willingly.

Honestly, boiling metal is quite an experience. It reminds me that people in the early modern period imagined hell as a giant fiery furnace. Looking into the cauldron, you understand what that motif meant to them.

What fascinates me most is the fact that even with the most modern technology, the same processes still have to be carried out as in ancient times. Of course, everything is more efficient, better, and safer today. But even so, for a perfect casting, the slag that forms on the surface of the molten metal has to be skimmed off. Two employees of the Japan Mint do this with long ladles and a small wheelbarrow, the inside of which glows fascinatingly. It’s a dangerous and strenuous job. I’m glad I don’t have to do it.

And that brings us to the next department, which Mr. Yamasaki will guide us through. He is the head of the Rolling Division, where metal ingots are rolled into coils.

I admit, it’s not the first time I’ve seen a coil being made. However, until now I’ve only been to factories that exclusively processed precious metals – and when it comes to precious metals, bars and coils are significantly smaller.

It’s a shame that no one is standing next to the ingot, but you can perhaps see how enormous the metal block is in relation to the door.

Gigantic ingots are transported on small metal carts that run on rails and play a cheerful tune. This is important because it prevents an inattentive employee (or me) from being run over by one of these carts.

While the production of the alloy is impressive, I can’t get enough of watching this process. There’s something playful about watching the glowing ingot being rolled into a long strip in the rolling mill. It rolls back and forth on a long conveyor belt, becoming a little longer with each new rolling cycle.

This step is not yet about achieving the precision required for the finished coil. Now it’s solely about speed. The longer the material has time to cool down, the more difficult it is to process. Consequently, after an initial winding, the long strip undergoes further processing in several stages.