According to the October, 2009 issue of InTech magazine, the trade journal of the International Society of Automation:
The cost of manufacturing money in the U.S. has increased. It costs 1.38 cents to manufacture a penny. To make a five-cent nickel, it cost[sic] 8.83 cents. The extra change is not for the machinery and is not because the value of the dollar is down. A penny is made of copper-plated zinc. Since 2003, copper is up 300%, and zinc is up 450%. Pennies have a zinc core and copper plating. Nickels are a copper-nickel alloy.Pretty soon, if the Treasury keeps printing money, it'll cost more than a dollar to print a dollar.