Small distribution boxes typically use 2 mm GI sheet for metal boxes or single-wall corrugated board of 2–4 mm thickness for cardboard packaging, depending on load and protection requirements.

Metal Distribution Boxes

For low-tension (LT) electrical distribution boxes, the standard fabrication material is 2 mm galvanized iron (GI) sheet steel. This thickness ensures sufficient structural strength, rigidity, and durability for outdoor use while allowing proper reinforcement with channels and fittings. The boxes are designed to withstand environmental exposure, mechanical stress, and provide adequate clearance for bus bars and cable glands. Additional features such as slanted roofs, overhangs, and IP-55 protection are incorporated without altering the standard 2 mm sheet thickness .

Cardboard Distribution Boxes

For small packaging or shipping distribution boxes, corrugated cardboard thickness is determined by the flute type, board grade, and number of layers rather than thickness alone. Typical standards include:

• Single-wall corrugated board: 2–4 mm thick, suitable for lightweight items like electronics, stationery, or small consumer goods .
• Flute types:
  • E-flute: ~1.5–1.6 mm, compact, good for printing and cushioning small items .
  • B-flute: ~3.2–4.0 mm, provides better crush resistance and stacking strength .
• Double-wall boards: 5–6 mm, used for medium-weight items requiring extra protection . The GSM (grams per square meter) of liners also affects strength, with high-strength liners starting above 350 GSM. Edge Crush Test (ECT) ratings of 23–32 are common for small distribution boxes to ensure stacking stability during storage and transport .

Selection Considerations

• Load and stacking: Choose thickness and flute type based on the weight of contents and expected stacking height.
• Protection vs. cost: Avoid over-specification; select the minimum thickness that ensures safe handling and transport.
• Environmental factors: For outdoor or humid conditions, metal boxes or moisture-resistant corrugated boards are preferred.
• Printing and branding: E-flute boards provide smoother surfaces for high-quality graphics, while B-flute offers better cushioning . In summary, 2 mm GI sheet is standard for small metal distribution boxes, while 2–4 mm single-wall corrugated cardboard is typical for small packaging boxes, with adjustments based on weight, stacking, and protection requirements.