Die cracks are a common type of coin error that occur when a die begins to crack or slightly break. As the die structure begins to deteriorate, cracks or fissures form along the design elements. When the planchet is struck, the metal fills these fissures, resulting in a raised line of metal in the newly minted coin.
Die crack
The primary cause of die cracks is the production process of the die, specifically the compression of the hub on the virgin die, which weakens the engraved areas. Additionally, prolonged use of dies used to strike high circulation coins can also affect the quality of the coins produced. In such cases, the mint tends to maximize each coinage to strike as many coins as possible.
Interposition of a foreign body between the coin and the round block during the striking phase can also cause cracks or fissures, sometimes taking on the shape of the foreign object interposed.
The evolution of a simple die crack to a branch die crack can be observed in the 6 coins of 50 Lire 1993 II type, which were all struck by the same cracked die. These specimens come from three different rolls, personally extracted in progression. A branched die crack occurs when a crack runs through some design elements, branching out into two or more distinct cracks that continue in different directions.