Distribution boxes can be made of either plastic or metal (including iron or steel), with the choice depending on application, environment, and safety requirements.

Plastic Distribution Boxes

Plastic distribution boxes are typically made from high-grade thermoplastics such as polycarbonate, ABS, PVC, or high-density polyethylene . They are lightweight, corrosion-resistant, and non-conductive, which eliminates the need to earth the enclosure itself . Plastic boxes are easier to install, cost-effective, and suitable for residential, light commercial, or high-humidity environments . Modern plastics are often flame-retardant and UV-stabilized, making them safe for indoor and some outdoor applications, though they have lower thermal stability compared to metal .

Metal (Iron/Steel) Distribution Boxes

Metal distribution boxes are usually made from galvanized steel, cold-rolled steel, stainless steel, or aluminum alloys . They offer superior mechanical strength, fire resistance, thermal stability, and electromagnetic interference shielding. Metal boxes are ideal for industrial or commercial applications where high current capacity, impact resistance, and fire containment are critical . However, metal enclosures can rust or corrode in humid or coastal environments unless treated or made from stainless steel .

Choosing Between Plastic and Metal

• Plastic: Best for indoor, residential, or corrosive environments; lightweight and non-conductive; cost-effective.
• Metal/Iron: Best for industrial, high-current, or high-temperature environments; strong, fire-resistant, and durable; may require grounding.

In summary, distribution boxes are available in both plastic and metal (including iron/steel), and the selection depends on environmental conditions, safety requirements, and installation needs .