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Hub retouching
Hub retouching The sub-category of coin errors known as “hub retouching” refers to mistakes made by engravers during the hub design phase. These errors can go unnoticed until the coins are distributed to banks and enter circulation as ordinary currency. Upon discovery of such errors, production is temporarily suspended so that the engraver can correct…
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Punching errors
Punching errors Punching errors are a type of coin error that encompasses all production errors of the die that can be found on design elements such as letters, numbers, and other distinctive features. The punching process involves the use of special “punches” that are compressed onto the coin to complete or refine the design elements.However,…
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Die deterioration
Die deterioration Die deterioration is a type of coin error that occurs when a die reaches the end of its useful life, causing the molecular structure of the metal alloy it is made of to alter. As a result of striking several thousand coins, the die begins to deform and lose its original molecular properties.…
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Die damage
Die damage Die damage is a type of error that occurs when a foreign object is placed between the die and the planchet during the minting process. When solid fragments enter the beating chamber while the press is in operation, they can cause scratches or dents in the die, which will then be reflected in…
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Crepa della zecca
Crepa della zecca Le crepe della zecca sono un tipo comune di errore di conio che si verifica quando una matrice inizia a creparsi o a rompersi leggermente. Man mano che la struttura della matrice inizia a deteriorarsi, si formano crepe o fessure lungo gli elementi di design. Quando la zecca viene battuta, il metallo…
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Bimetallic planchet errors
Bimetallic planchet errors Struck core Struck core is a type of coin error that can occur during the assembly process of the two components. In some cases, the outer ring fails to descend into the vacuum of the rotating disc that feeds the planchets inside the beating chamber, resulting in only the core being minted.…
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Cracked planchet
Cracked planchet Cracked planchets are a common type of coin error that occurs due to impurities in the alloy, which weaken the entire length of the planchet. Poorly mixed alloys and incorrect annealing of the non-minted planchet can also contribute to this defect. A planchet is considered to be cracked when it has developed a…
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Folded edge
Folded edge The folded edge is a type of coin error caused by a marginal break along the edge of one of the blanking punches installed on the punching press. During the shearing of the planchet, the broken punch generates a metal tab on the edge, which is then flattened inward over the surface of…
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Cutting errors – Clips
Cutting errors – Clips Elliptical clip Cutting errors, specifically clips, are a type of coin error that occur when a portion of the planchet is accidentally cut out during the production process. This error can happen during the blanking process, when a circular disk is cut from the metal strip that will become the planchet.…
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Alloy errors
Alloy errors It is common for coins to have imperfections in the composition of the metal alloy, although extreme cases are less frequent. These variations in the alloy’s composition can arise during the casting process in the foundry.To obtain planchets that comply with the issue decree, it is essential to dose the different metals that…