Some coins have ridges around their edges because of “coin clipping.”

Run your fingers along the edge of a dime and you’ll notice the coin has a crimped edge. If you were to count those tiny grooves and valleys, you’d find 118 ridges, one less than is found on a quarter. But not all American coins have ridges, and here’s why. Rippled edges on larger-denomination coins have been a part of American currency since the U.S. Mint’s early days, and they were a clever solution to a massive currency conundrum: counterfeiting and fraud. Around the 1700s, coins were an easy target for money-generating schemes, including coin clipping: People would clip or shave off slim portions of a coin’s outer edge, cashing in the scraps of precious silver and gold. In Great Britain, coin clipping was so common that the crown deemed it a form of treason. In early North American settlements, “coining” — the actual production of fake coins — was equally problematic.

Knowing this, American coin makers added grooved bands — called reeded edges — to the thin sides of dimes, quarters, and larger coins then made from silver, in order to prevent shaving and make fraud more difficult. (Pennies and nickels remained smooth-sided since they were pressed from less-valuable copper and nickel.) But reeded edges lost some of their utility when the Coinage Act of 1965 changed the composition of dimes and quarters from silver to a copper-nickel blend. Reeded edges remain today as a design choice, and because they help people with visual impairments differentiate among coins.