After the design for a coin is chosen, the image is transferred to a plaster model. Rubber is poured over the plaster to create a rubber mold. Epoxy is then poured into the mold. Once the epoxy hardens, it is removed from the mold and sent to the hub making area.

 

Since the epoxy image is much larger than the diameter of the intended coin, the image must be reduced. A machine called a Janvier transfer reducing machine reduces the image onto a master hub. The master hub is an exact image of the model (in relief). Once the hub is created, it is heated to a very high temperature and then cooled (quenched) in a vat of oil. Quenching the heated hub hardens the steel further.