... A36, A1011, A569, Q235, S275JR, SS304, Mild steel & Low carbon steel, etc5Surface TreatmentBlack, self colour, hot dip galvanized, painted, ... spray coating 6Grating StylePlain / Smooth, Serrated /teeth, I bar, serrated I bar ... AS1657-1985,Germany: DIN24537-1-2006, Japan:JIS bar steel grating grid drain trench covers (factory)