Most U.S. coin denominations have small raised ridges on their edges. Sometimes those edges are sharp and crisp, other times they have been worn down due to age. One reader wanted to know if those ridges were the result of the manufacturing process, or if they serve a useful function or purpose. Today we’ll explore this little life mystery.
According to the United States Mint, ridged or “reeded” edges serve two main purposes.
Originally, the US Mint added reeded edges to coins made them harder to counterfeit. While it was relatively simple to create a bogus coin in early America, the process was tedious and time consuming. It could take an entire day to create a fake, passable US coin by hand. For the amount of time invested, it simply wasn’t profitable to fake coins. Most counterfeiters focused their attentions primarily on banknotes (dollar bills).
To make a worthwhile profit off of counterfeit coins, counterfeiters would need to mass produce them in a short period of time. This would require advanced machining equipment which was expensive as well as rare in early America. Reeded edges made the process much more complex, further added to the difficulty.
Time For A Shave
The second reason coins have ridges was to prevent people from filing down or “clipping” the coins.In 1793, the first U.S. coins were linked to the silver standard. That meant that a half dollar coin contained half as much silver as a silver dollar coin, a quarter contained one-fourth the silver, and so on. The ridged edges prevented people from skimming the coins’ edges down for extra silver.
Skimmers wouldn’t become rich by the practice, but over a short period of time, those who clipped coins could save up a tidy sum by saving their silver and gold shavings. The coins that were clipped were lighter, but returned to circulation and usually accepted at face value.
While coins these days aren’t made of precious metals, the government decided to retain the trademark reeded edges on certain coins to help the visually impaired. The dime and the penny, for example, are roughly the same size, so the ridges help people distinguish them.
Bonus fact: The movie cliche of biting a gold coin is not to verify it’s real gold. Gold coins are tooth-breakingly hard. The practice was to check for another nasty gold-thieving technique of hollowing out coins. If a coin collapsed when bit, you knew it had been emptied of its core.