Most electrical conductors are made of copper, aluminum, or which material in older systems?

In older electrical systems, steel was commonly used as a conductor, particularly in applications where strength and durability were prioritized over electrical efficiency. Steel has a high tensile strength, making it suitable for overhead transmission lines and certain structural elements of electrical systems. However, it is important to note that steel is not as conductive as copper or aluminum, which are preferred for their superior electrical properties.

The use of steel in electrical applications often involved special coatings to improve its conductivity and resistance to corrosion. Even though copper and aluminum have become the standard for most modern electrical conductors due to their excellent conductive properties and lower overall resistance, steel's historical usage is significant in understanding the evolution of electrical systems. This foundational knowledge helps electricians appreciate the materials used in older installations and their associated properties.