119 ridges. That’s how many you’ll find running around the edge of a U.S. quarter. A dime has 118. Most people have handled thousands of these coins without ever thinking about that number, or asking why the ridges are there in the first place.

The answer goes back centuries, and it starts with theft.

When coins were struck from gold and silver, criminals developed what the trade called “shaving.” The scheme wasn’t complicated. You’d take a coin worth a dollar, scrape metal from the rim, pocket the filings, and pass the coin along as if nothing had happened. Do it systematically across enough coins and you’d accumulated real precious metal essentially for nothing. The coin still looked like a coin. Nobody checked the edges. The fraud was nearly invisible.

Reeding killed that trick dead. That’s the technical name for those ridges, by the way, reeding, and the design solved the shaving problem in the most direct way imaginable. File down any portion of a reeded edge and the grooves vanish right where you worked. Anyone who glances at the coin can see something’s off. The evidence is built into the design itself.

So here’s what a lot of people don’t know: pennies and nickels have never had ridges, and that’s not an oversight. Lower-value coins were always made from cheaper base metals, which meant shaving them wasn’t worth the effort. The metal you’d collect wasn’t valuable enough to justify the risk. Quarters and dimes held onto their reeding because those denominations, being worth more, attracted more criminal attention. That calculus carried forward even after U.S. coinage moved away from precious metals entirely, something that happened gradually through the mid-20th century.

Here’s the thing, though. Modern quarters and dimes aren’t silver. They’re copper and nickel bonded together, a sandwich construction you can actually see on the edge of a worn coin. Nobody’s shaving a clad quarter for profit. The original reason for reeding doesn’t really apply anymore.

But the ridges stayed, and they’re still doing real work.

Think about digging through your car’s center console while you’re watching the road, or sorting change in a dark room, or moving fast at a register. Smooth edge means penny or nickel. Ridged edge means dime or quarter. Your fingers can sort that out in about half a second without your eyes getting involved at all.

That matters most for people with visual impairments, who rely on tactile distinctions to identify money every day without any alternative. The American Foundation for the Blind has pointed to these edge features as a genuine accessibility tool, one that tends to get overlooked when people talk about inclusive design. It’s not glamorous design thinking. It’s a centuries-old anti-fraud feature that turned out to have a second life as something more quietly important.

“It’s one of those cases where the solution to one problem accidentally solved another,” said a coin historian I spoke with at a regional numismatics event earlier this year, pointing out that most currency redesigns don’t generate that kind of double utility.

Beyond accessibility, the ridges help vending machines read coins mechanically, give collectors a quick way to sort through jars of change, and let parents teaching kids about money at the kitchen table make the lesson tactile instead of abstract. Those aren’t small things. They add up across millions of daily transactions.

The actual manufacturing process is worth knowing, too, if you’re curious how 119 ridges end up on every single quarter. Family Handyman breaks it down clearly: large metal coils get cut into flat discs called blanks, those blanks get heat-softened and cleaned, then they run through an upsetting mill that raises the rim. Once a blank becomes a planchet, a coin press stamps the front and back designs simultaneously, applying enough force to set the reeding into the collar around the die.

That’s the whole story, really. An anti-counterfeiting measure from the era of gold coins, preserved through inertia and redesign cycles, now doing accessibility work that its inventors couldn’t have anticipated. Some design solutions don’t need to be replaced. They just need to outlast the original problem.

The quarter in your pocket right now has 119 ridges. Count them if you don’t believe it.