Electro-galvanized cable trays are coated with a layer of zinc through an electroplating process. Mean Coating Mass: Refers to the mass of the zinc coating per unit area of the entire workpiece, which can be determined by the gravimetric (dissection) method, used for arbitration. Dull. This white paper compares the High Resistance (HR) and Hot-Dip Galvanising (HDG) solutions and highlights the new High Resistance range, ZnAl wiremesh, ZnMg metal cable trays and accessories and ZnNi screws and bolts. The finish is designed to extend the life of the tray and maintain its functionality. Fiberglass: Non-metallic option, immune to rust. Cost-effective: One of the more.