Coin edge

Coin edges may be plain (smooth) and patterned.

Reeded edges are often referred to as "ridged" or "grooved" (US usage), or "milled" (UK usage). Some coins, such as United States quarters and dimes, have reeded edges. Reeding of edges was introduced to prevent coin clipping and counterfeiting.

The main techniques of coin edging are edge mills of various types, which put a pattern on a smooth edge after a coin and coin mills with edge ring, which pattern the edge at the time when the coin is being milled.