Welded Steel Grating Material:Stainless steel,Hot-dipped Galvanzied,Alu Use:platform,ladders,floor drain,floor drain ISO9001 Serrated Steel Welded Grating Material:steel grating is made ... '' & 4'' etc 4Material GradeASTM A36, A1011, A569, Q235, S275JR, SS304, Mild steel & Low carbon steel, etc5Surface TreatmentBlack, self colour, hot dip galvanized, painted ...