... actually made from copper, aluminum and oth er materials, while galvanized steel grating is the mostly used one due to ... more than twice of cast iron products. Hot-dip galvanized treatment: Good rust-proof property, maintenance-free replacement. ... & Low carbon steel, etc5Surface TreatmentBlack, self colour, hot dip galvanized, painted, spray coating6Grating StylePlain / Smooth, Serrated /teeth, I bar ...