Where is the zinc coating on galvanized cable trays

The zinc coating on galvanized cable trays covers all steel surfaces, including side plates, base plates, edges, holes, and welds, providing corrosion protection. Coating Location and CoverageHot-dip galvanized cable trays are fully immersed in molten zinc after fabrication, which ensures that all surfaces, edges, holes, and welds are coated with a thick, protective zinc layer. This process creates a zinc-iron alloy layer and a pure zinc layer, offering superior adhesion and corrosion resistance, making it ideal for outdoor or harsh industrial environments.

The coating is self-healing, meaning small scratches or cuts are protected by the surrounding zinc acting as a sacrificial anode. Pre-galvanized (mill-galvanized) cable trays are coated before fabrication, typically on steel sheets or coils. The zinc layer is applied to the flat steel surfaces, but areas exposed during cutting, bending, or welding may have reduced coverage.

These trays are generally suitable for indoor or mild environments due to the thinner zinc layer. Zinc plating can be applied after fabrication to improve protection at weld points and edges. Coating ThicknessHot-dip galvanized trays: Side and base plates (1.

5–3 mm thick) require a zinc thickness of at least 45 µm (≈325 g/m²), while heavier components like brackets (>3 mm) require ≥55 µm. Pre-galvanized trays: The zinc layer is thinner, typically around 0. 32 ounces per square foot per side, providing moderate corrosion resistance suitable for indoor use.

Summary

The zinc coating is applied to all steel surfaces in hot-dip galvanized trays, including edges, holes, and welds, ensuring maximum corrosion protection. Pre-galvanized trays have zinc on the flat steel surfaces, but welds and cut edges may have less coverage, making them more suitable for indoor or less corrosive environments.