... the mostly used one due to its economic cost and good property.Steel grating, with robust design and spanning abilities, ... free replacement. Anti-theft design: The cover and the frame is joint with hinge offering security, safety and open ... GradeASTM A36, A1011, A569, Q235, S275JR, SS304, Mild steel & Low carbon steel, etc5Surface TreatmentBlack, self colour, hot dip galvanized, painted, spray ...