A collar break happens during the coin striking process. The collar is a piece of metal that encircles the coin blank (or planchet) as it is struck by the dies. Its primary function is to form the coin’s edge, whether it be smooth, reeded, or lettered, and to ensure the coin’s diameter remains consistent. A collar break occurs when there is a crack or failure in the collar itself, leading to a malfunction in how the coin’s edge is formed.
Collar Break
This error can be caused by several factors:
Wear and Tear: Over time, the continuous impact of striking coins can wear down or crack the collar.
Improper Installation: If the collar is not correctly installed, it might not withstand the pressures of coin striking.
Material Flaw: The material of the collar might have inherent flaws, making it susceptible to breaking under the stress of minting.
Collar break errors manifest in various ways depending on the nature of the break and the stage of the minting process when the break occurs. Here are several scenarios:
Irregular Edge Patterns: The most common indicator of a collar break is an irregular pattern on the coin’s edge. Instead of a uniform reeded or smooth edge, the coin may exhibit areas of distortion or uneven patterns.
Variations in Coin Diameter: Since the collar also serves to maintain the coin’s diameter, a break can lead to coins that are not perfectly round or have variations in diameter. This might not be immediately noticeable without precise measurement tools.
Partial Collar Strikes: In some cases, the break allows part of the coin to escape the confines of the collar, resulting in a partial collar strike. This can give the coin a “railroad rim” appearance where one part of the edge is higher or more defined than the rest.
Overstrikes and Double Strikes: A broken collar might fail to eject the coin properly after the first strike, leading to overstrikes or double strikes. These errors create additional visual anomalies on the coin’s surface and edge.