Steel weighs 7850 kilograms per cubic meter, or 489.8 pounds per cubic foot. Stainless steel weighs between 7480 and 8000 kilograms per cubic meter, depending on its exact composition. A 0.25-inch-thick steel plate weighs 10.2 pounds per square foot.
Steel is an alloy of iron and carbon. Steel is created by heating iron in the presence of oxygen. Iron is a soft, malleable metal. Adding 1.5 to 2 percent carbon creates steel, which is a stronger but less malleable metal. Stainless steel is steel with varying amounts of chromium added to prevent rust from forming. Cast iron is steel with a carbon content higher than 2 percent. It is not malleable but can be melted and cast in molds.