The lines on coin edges were not made randomly and were invented a long time ago
Even in the era of digital wallets and contactless payments, we still occasionally hold ordinary change in our hands. And you, like me, have probably noticed that coins always have ridged edges. It turns out this is not a random design element but a brilliant invention from the past to protect against cunning theft. This technological measure has successfully survived to the present day.
What Are the Ridges on Coin Edges For
Up until the mid-20th century, the denomination of many coins literally corresponded to the value of the metal from which they were cast. For example, the first American dollars, issued in 1794, were made of nearly 90 percent silver. It was precisely the value of the material that gave rise to a popular form of fraud — coin clipping.
Fraudsters carefully shaved off a thin layer of metal around the entire perimeter of the coin. If done carefully enough, the size and weight visually hardly changed. The criminal could go to the market and pay with the damaged coin as if nothing happened, then melt down and sell the collected silver or gold shavings.
To stop this invisible theft, a special relief pattern began to be applied to the edges — the so-called reeded edge. The idea proved incredibly effective because if an edge with ridges was damaged or smoothly shaved, any merchant would immediately spot the tampering. Incidentally, the famous physicist Isaac Newton, upon becoming Warden of the Royal Mint of Great Britain in 1696, actively implemented this very method to combat counterfeiters, although similar technologies had been used in Europe since the 16th century.
Why Some Coins Have Smooth Edges
If ridges are so useful, the logical question arises about their absence on some coins. For example, American pennies and nickels, like many small denominations in other countries, traditionally have completely smooth edges. This was explained by the authors of the Mental Floss website.
The answer lies in pure economics. Small denominations were originally minted from cheap metals, so clipping them was pointless. The cost of time spent and the risk of being caught significantly exceeded the value of the copper shavings obtained. Since the potential profit was essentially zero, there was no need to protect such coins with a complex relief pattern.
Why Ridges on Coin Edges Still Exist Today
By the mid-20th century, the world faced a silver shortage, and governments began abandoning the link between money and precious metals. In the USA, this was officially established by the Coinage Act of 1965, which gradually reduced the silver content in circulating coins to zero. The threat of clipping definitively became a thing of the past, but the ridged edges remained.
The minting process works so that a metal blank is struck by a special tool — a die — while being held in place by a component called a collar. It is the collar that forms the edge. When mints switched to cheap alloys, the government decided not to spend the budget on new machines and dies. The old equipment continued to work, applying the now-unnecessary protective pattern to copper-nickel blanks.
Later, this manufacturing habit turned into a standard, as it was discovered that the ancient method had gained a new social function. Thanks to the different edge textures, visually impaired people find it much easier to identify denominations by touch, without confusing small coins with each other.
How Many Ridges Are on Coin Edges
If you grab a handful of change and look closely, you can notice that the number and width of ridges on coins vary. Historically, this parameter was not regulated by law, so each mint had its own internal specifications.
In the 19th century, this led to noticeable visual differences. For example, ten-cent coins from the now-closed Carson City mint had only 89 wide ridges. Meanwhile, the Philadelphia mint during the same years produced identical coins with 113 thin, closely spaced ridges.
Today, production has become standardized. The official requirements for the number of ridges on modern American coins are as follows:
- Dime (ten-cent coin) — 118 ridges;
- Quarter dollar — 119 ridges;
- Half dollar — exactly 150 ridges;
And here is the number of ridges on Russian coins:
- 1 kopeck — smooth edge, no ridges;
- 5 kopecks — smooth edge, no ridges;
- 10 kopecks — smooth edge, no ridges;
- 50 kopecks — smooth edge, no ridges;
- 1 ruble — 110 ridges;
- 2 rubles — 84 ridges, divided into 12 sections;
- 5 rubles — 60 ridges, divided into 12 sections;
- 10 rubles — 72 ridges: 6 sections of 5 reeds and 6 sections of 7 reeds.
It turns out that the ridged edge of a coin is a rare example of a technology that outlived the problem it was created to solve. Every time you pay with cash, you touch an unusual engineering solution from the past that proved so successful it became a global standard.
