Bimetallisia

Bimetallisia refers to items or phenomena involving two different metals. This term is most commonly associated with bimetallic strips and bimetallic coins.

A bimetallic strip is created by bonding two metals with different coefficients of thermal expansion together. When subjected to a change in temperature, the strip will bend. The metal with the higher coefficient of expansion will expand more, causing the strip to curve towards the metal with the lower coefficient of expansion. This property is utilized in various applications, such as thermostats, circuit breakers, and oven thermometers. The differential expansion of the metals provides a mechanical response to temperature fluctuations.

In the context of currency, bimetallic coins are those that are composed of two distinct metals, often in different parts of the coin. This can be achieved through various manufacturing processes, such as creating a ring of one metal and an insert of another, or by cladding one metal onto a core of a different metal. Bimetallic coins are often used to create coins of higher denominations or to incorporate security features. They are also visually distinct, with the contrasting metals offering a unique aesthetic. Examples of bimetallic coins include some versions of the Euro coins and certain commemorative issues. The use of two metals can also affect the coin's durability and resistance to wear.