The composition of United States five-cent pieces, often called nickels, underwent changes during the mid-20th century. Coins produced in 1964 are a point of specific inquiry regarding their metallic content. Unlike dimes, quarters, and half-dollars from that year, which contained 90% silver, the five-cent piece composition remained consistent with its established alloy.
The standard alloy for the five-cent piece had been, and continued to be in 1964, a blend of 75% copper and 25% nickel. This decision to maintain the copper-nickel composition for the five-cent piece was driven by factors such as cost and availability of materials, as well as maintaining vending machine compatibility. Retaining the established metal mix ensured minimal disruption to commerce and industry.