According to the United States Mint, a dime has a diameter of 17.91 mm (0.705 inches), is 1.35 mm thick and weighs 2.268 grams (0.08 ounces). This coin has the smallest diameter and is the thinnest of all U.S. coins.
Dimes are made of cupronickel, which is an alloy of copper that contains nickel and other elements. Dimes contain 8.33 percent nickel with a balance of cupro, which is copper and usually a trace of manganese. Cupronickel gives dimes their silver color.
The edge of the dime is reeded with 118 reeds. These are the series of grooved lines around the edge of dimes, which are put there to discourage counterfeiting of coins. Dimes were originally made of gold and silver, and people tried to file the edges to recover the precious metals.