... and 100mm; of which 50 and 100mm arerecommended3) Advantages of steel grid planks: light weight, strong intensity, big load capacity, ... GradeASTM A36, A1011, A569, Q235, S275JR, SS304, Mild steel & Low carbon steel, etc5Surface TreatmentBlack, self colour, hot dip galvanized, painted, spray ... 1985,Germany: DIN24537-1-2006, Japan:JIS Durability hot dip galvanised steel grating trench cover (factory)