The United States five-cent coin, widely known as the nickel, is a ubiquitous part of daily commerce. This small denomination plays a significant role in transactions across the nation. This article explores the specific metals used in the US nickel, tracing its composition from its inception to its present form.
The Modern US Nickel
The contemporary US nickel is primarily composed of an alloy known as cupronickel. This specific mixture consists of 75% copper and 25% nickel. Despite its common name, the coin contains significantly more copper than nickel, with the latter primarily contributing to its silvery appearance. The standard diameter of the coin is 21.21 millimeters and it weighs 5 grams. This specific cupronickel blend has been the consistent standard for the US nickel for over a century.
Evolution of the Nickel’s Metals
The US five-cent piece first adopted its copper-nickel composition with the introduction of the Shield Nickel in 1866. This decision was formalized in 1866, authorizing a five-cent coin made of 75% copper and 25% nickel. Before this, five-cent coins were silver half-dimes, but silver hoarding during the Civil War necessitated a change to base metals.
A notable deviation from this standard occurred during World War II, when nickel became a strategic metal needed for the war effort. From mid-1942 through 1945, the composition of the five-cent coin was temporarily altered. These “wartime nickels” were made of 56% copper, 35% silver, and 9% manganese. This change conserved nickel, which was redirected for use in armor plating and military machinery. Following the war, the US Mint returned to the original 75% copper and 25% nickel composition in 1946, which has remained the standard ever since.
Characteristics of the Alloys
The choice of cupronickel for the US nickel is attributed to its practical properties beneficial for coinage. This alloy exhibits excellent resistance to corrosion and tarnishing, ensuring that coins remain functional and aesthetically acceptable for extended periods in circulation. Its hardness contributes to durability, allowing coins to withstand constant handling and wear.
Cupronickel also possesses suitable malleability, enabling the clear and precise striking of intricate coin designs. Furthermore, the alloy’s electrical conductivity is important for modern coin-handling and vending machines, which rely on specific metallic signatures for coin identification. During World War II, the temporary silver, copper, and manganese alloy was specifically designed to mimic the electrical properties of the standard cupronickel, ensuring continued compatibility with vending machines.