Which materials are not acceptable for use in lightning protection systems?

In lightning protection systems, the choice of materials is critical for ensuring the effectiveness and safety of the system. Galvanized or plated steel nails, screws, or bolts are not acceptable because the galvanization or plating creates a barrier between the steel and the electrical conductivity required in a lightning protection system. When lightning strikes, the current needs to flow freely through the conductors without any resistance or interference, and coatings like galvanization can inhibit that necessary conductivity.

In contrast, copper nails, aluminum screws, and brass bolts are acceptable options. Copper is an excellent conductor of electricity and is often used in lightning protection systems due to its corrosion resistance and ability to carry high currents. Aluminum is also a good conductor, lighter than copper, and is commonly used in various electrical applications. Brass, which consists mainly of copper and zinc, boasts good conductivity and strength, making it suitable as well. Therefore, the unfit nature of galvanized or plated materials for use in lightning protection systems directly relates to their inability to ensure optimal electrical conductivity.