Why Coins Have Ridges

This episode explains that ridges on coins originated as a clever defense against one of history’s oldest forms of fraud: coin clipping. In ancient and medieval times, coins were made of precious metals like gold and silver, and their value depended on weight. People secretly shaved tiny amounts of metal from coin edges, kept the filings, and spent the lighter coins at full value. Over time, this practice drained economies and forced governments to fight illegal clipping with harsh punishments.The breakthrough came in the 1600s and 1700s, when new minting machines made it possible to imprint grooves—ridges—along coin edges. With ridges, any attempt to shave metal became immediately visible. The ridged edge restored trust in currency and shifted confidence from the coin’s weight to the integrity of the minting system itself.Even though modern coins are mostly made from inexpensive metals and no longer need clipping protection, ridges remain useful. They help people distinguish coins by touch, assist machines in verifying authenticity, and preserve a historical reminder of how money once worked. Today, those little grooves represent centuries of ingenuity in protecting value and keeping economies honest.