Radiators were traditionally made of which material?

Radiators were traditionally made of cast iron due to its excellent thermal properties and durability. Cast iron has a high capacity for holding heat, allowing for steady and efficient heat distribution in heating systems. Additionally, its robust nature makes it resistant to warping and damage over time, which was important in the context of older heating systems where radiators often experienced fluctuations in temperature and pressure.

The other materials listed, while they may also be used in the manufacturing of radiators today, do not have the same historical significance in traditional radiator construction. Steel, for instance, is lighter and provides easier installation but does not hold heat as effectively. Stainless steel is known for its corrosion resistance, making it ideal for certain modern applications but less common in traditional designs. Copper, though excellent for heat transfer, is typically used in piping and boiler systems rather than radiators themselves, mainly due to cost and structural considerations. Therefore, cast iron remains the hallmark material for traditional radiators.