Solo anello esterno coniato
Similar to the broad typing, this type of error also derives from a malfunction of the monetary press.
At the moment of minting, three elements come into action simultaneously due to the pressure exerted by the monetary press, namely the upper die, the lower die and the collar.
As we have already seen in the sub-category broadstrike, the collar is the retaining ring of the roundels that serves to define the diameter and any incisions on the edge of the coin.
In a regular beating, the planchet is pushed by the feeding arm into the hole of the collar, rests on the lower die, while the upper die descends and with one stroke transforms it into coin. Immediately afterwards the lower die rises and the feeding arm extracts the newly minted coin.
Sometimes, the upper mint strikes the planchet when the collar is in a lower position than the pre-established height threshold. When this happens, the coin produced by such a partial collar will always have an irregular and uneven outline.
Very rarely, this type of striking error can be combined with other types of errors (E.B.11 and E.B.13).