Pure iron has relatively few applications, but enormous quantities of the metal are used in the manufacture of steels. Steels are invaluable as construction materials. They are used widely in cars, ships, bridges, building girders, tools, containers and reinforced concrete, as well as in thousands of others of everyday objects.
Ruthenium and osmium have far fewer uses than iron, but both metals are used to produce platinum alloys of great hardness. Such alloys are used in fountain pen points, where hardness and resistance to corrosion are essential. In common with the rest of the platinum metals, ruthenium and osmium are excellent catalysts.
