For hot-dip galvanized steel cable trays, the standard zinc coating thickness is typically 45–55 µm, depending on component thickness, while electro-galvanized trays require a minimum of 12 µm.

Hot-Dip Galvanized (HDG) Cable Trays

Hot-dip galvanization involves submerging steel components in molten zinc, forming a thick zinc-iron alloy layer with excellent corrosion resistance. This is the preferred method for outdoor, industrial, or coastal environments .

• Tray Sheet Metal Thickness 1.5–3 mm: Minimum local zinc thickness 45 µm (coating mass ≥ 325 g/m²)
• Heavier Components (>3 mm): Minimum local zinc thickness 55 µm
• Local Thickness: Measured at multiple points; all points must meet the minimum
• Mean Coating Mass: Determined gravimetrically for the entire workpiece
• ASTM A123/A123M Coating Grade 65: Average zinc coating weight 460 g/m² per side or thickness 0.065 mm (65 µm) per side for standard hot-dip trays Repairs for cuts or damaged areas should use compatible zinc-rich compounds to maintain corrosion protection.

Electro-Galvanized Cable Trays

Electro-galvanization deposits a thin, uniform zinc layer via electrolysis. It provides limited corrosion resistance and is suitable for less harsh environments .

• Minimum Zinc Thickness: 12 µm
• Standard Reference: GB/T 26941.1-2011

Key Considerations

• The thickness requirement depends on the tray component (side plates, base plates, brackets, supports)
• Environmental exposure: Outdoor or corrosive environments require HDG with higher thickness
• IEC 61537 compliance: Ensures corrosion resistance, mechanical strength, and long-term durability In summary, for a typical cable tray labeled "6" (assuming standard steel thickness), hot-dip galvanized trays should have a zinc layer of at least 45 µm, while electro-galvanized trays require at least 12 µm. For critical or outdoor installations, HDG with 55–65 µm is recommended to ensure long-term protection.