What is a South African 5C coin made of?

From 1961 through 1964 - silver (2.83 grams at 50% pure - 0.0455 troy ounces ASW [Actual Silver Weight])

From 1965 through 1982 - nickel (2.5 grams)

From 1990 onward - copper-plated steel (4.5 grams)