What are the primary materials used for raceway systems?

The primary materials used for raceway systems are steel and aluminum because they offer a combination of strength, durability, and resistance to environmental factors. Steel raceways provide excellent mechanical protection and can support heavy loads, making them ideal for a variety of installations in industrial and commercial settings. On the other hand, aluminum raceways are lightweight, resistant to corrosion, and can be easily installed, which is beneficial in situations where weight is a concern or when working with corrosive environments.

Together, these materials meet the requirements of protection for wiring while also addressing the needs for installation efficiency and longevity. The other options listed do not provide the same level of practical application in raceway systems.