Partial collar

The coin error type known as “partial collar” is similar to broad typing in that it results from a malfunction of the monetary press during the minting process. During the minting process, three elements come into action simultaneously: the upper die, the lower die, and the collar.

As previously discussed in the sub-category of 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. During regular striking, 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 a coin. Immediately afterwards, the lower die rises and the feeding arm extracts the newly minted coin.

However, in the case of partial collar error, the upper die strikes the planchet when the collar is in a lower position than the pre-established height threshold. As a result, coins produced by partial collar error always have an irregular and uneven outline. It is important to note that this type of striking error is very rare, but it can sometimes be combined with other types of errors.