Struck through planchet

Struck through planchets is a type of coin error that occurs when two planchets are mistakenly fed into the beating chamber at the same time while the press is in operation. The overlap can be total or partial, and the affected area always presents a difference in height, resulting in a classic round shape that is flat and devoid of design elements, as opposed to brockage.

In rare instances, a previously struck coin involved in another type of striking error may not be properly ejected by the ejection mechanism. At the same time, a new planchet is inserted from the feeding arm and struck together with the non-ejected coin. During the minting process, the non-minted planchet will partially or totally delete the reliefs of the coin not ejected, resulting in an overlap.

Coins with this type of error are easily detected by quality controls, and therefore it is assumed that the appearance of certain specimens on the market occurs at the hands of some worker who illegally transported them outside the Mint.