... 3.Plain, I-shape, Serrated 4.Galvanized, Black, Steel Grating Size fields:1) Bearing Bar (Load Bar) Specifications ... recommended, America standard is available.4) Steel grating Material: Mild Steel (Low Carbon Steel) or Stainless Steel5) Surface Treatment: Untreated ... treatment offers good corrosion resistance Good ventilation, good natural lighting, good heat radiation property, explosion-proof, good ...