Copper is unique chemical element.
Steel. I think. The can be made of steel, aluminum, or copper.
A 10p coin in the UK is made of a combination of metals, primarily copper-plated steel. It consists of 75% copper and 25% nickel. The outer layer is made of copper and the inner core is made of steel.
Because
The Iraqi coins made for general use since 1960 are made of nickel, copper-nickel, stainless steel, copper plated steel and nickel plated steel.
Irish (Eire) "copper" decimal coins issued from 1971 to 1988 were made from bronze consisting of about 97% copper, the remainder being tin and zinc. Irish (Eire) "copper" decimal coins issued from 1988 to 2001 were made from copper plated steel.
lead, copper, steel
Copper is a better conductor of heat than steel.
American nickels are made of 75% copper and 25% nickel Canadian nickels used to be pure nickel but are now made out of steel.
A Mike is made of steel. A Steve, however, is made of copper.
There isn't a "steel copper" penny. US cents were made of steel - but no copper - during 1943 to conserve copper for use in ammunition. Up till 1982 other dates of cents were made of a bronze alloy that was 95% copper, but no steel. A few 1943 cents were struck in bronze by accident but these are very rare and none have been found in many years.
Copper plates on a steel armature structure.
Steel , Brass, Bronze, Copper,