Which material is typically NOT used for anchor bolts and nuts in substation foundations?

The use of materials for anchor bolts and nuts in substation foundations is crucial for ensuring stability, durability, and resistance to environmental factors. Plastic is not a suitable material for this application due to its tendency to degrade under load and exposure to weather elements, which can compromise the structural integrity of the foundation.

In contrast, materials like hot-dipped galvanized steel and stainless steel are often used because they provide excellent corrosion resistance, which is important in outdoor environments where substations are located. Cold-rolled steel, while not as corrosion-resistant as galvanized or stainless steel, is also commonly used due to its strength and ability to be treated for enhanced durability. Therefore, plastic stands out as the least appropriate option for anchor bolts and nuts in substation foundations, as it lacks the necessary mechanical properties and longevity required for such critical structural components.