Are cable trays made of sheet metal

Common cable trays are made of galvanized,, aluminum, or glass-fiber reinforced plastic. The material for a given application is chosen based on where it will be used. Galvanized tray may be made of pre-galvanized steel sheet fabricated into tray, or may be hot-dip galvanized after fabrication. When galvanized tray is cut to length in the field, usually the cut surface will be painted with a zinc-rich compound to protect the metal from corrosion. [pdf]