Superior Manufacturing Reduces Errors

December 3, 2014

A 2012 Dime demonstrates a broad strike defect
A 2012 Dime demonstrates a broad strike defect

The Mint currently produces billions of circulating coins a year. In the past, the sheer quantity of manufactured circulating coins produced an occasional mistake in the planchet, or blank, die or striking process and an “error” coin popped out of the press. These days, virtually all error coins and defects are found and recycled before they ever leave the United States Mint. The few that do make it into circulation, though, are often perceived to be collectibles. Unfortunately, for collectors, the quantity of error coins is getting to be fewer and fewer. The Mint has been steadily improving manufacturing processes that are resulting in fewer of these error coins.

The Mint Quality Index (MQI) describes the “measurable quality attributes that provides an objective measurement of performance in meeting high quality standards on finished coins.” What this means for the non-manufacturing crowd is that the Mint has developed a scoring system to rate its own coins.

The Mint monitors MQI results for both circulating, numismatic, and bullion coins. In a weighted scale that targets 100 as a perfect score and measures “minor,” “major” and “critical” defects, this number was 74.9 for circulating coins in 2007. Through zero-defect targeted efforts that include sampling, die inspections and yearly summits where Mint employees from each facility share knowledge and standardize approaches, 2014 saw the combined Denver and Philadelphia circulating MQI reach in excess of 99.3.

No matter who you talk to, circulating error coins carry value. For most people, this value is on the face of the coin. Numismatists find error coins to be interesting additions to their collection. The Mint sees an error as an opportunity to continue to improve as a world-leading manufacturer of coins.

Finding circulating error coins was never easy to begin with and, thanks to the talented people at our Philadelphia and Denver facilities, finding these coins has gotten even harder.


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