Die clashes are marks on the dies by their clashing. Die clashes occurs when the press is active and that there are no blanks between them. After the clash, all coins minted with this same die will present these marks.
The marks correspond to the contour of the pattern and/or the legend on the other side of the coin. Because the dies are not always replaced at the same time, we do not find necessarily marks on both sides of the coin.
It may happen occasionally, for various reasons, that the blank is not channeled directly into the striking room. As a result, the machine begins to strike, but with an empty room causing the two surfaces of the dies come in contact with each other. During this contact, which is still of considerable pressure, there is exchange of the highest parts of the design from one die to another.