Why do dimes and quarters have ridges on the their edges?
However pennies and nickels do not.
Best Answer - Chosen by Asker
This goes back to much earlier times when high denomination coins were actually made of gold or silver. Before the ridges were added, some unscrupulous people would file small amount off around the edges, then sell the metal shavings. The ridges were added to show if the possessor of a coin may have tampered with it. Copper and cheaper metal coins didn't need the ridges because it was not worth someone's time to shave the edges.
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