... property 3.Maintenance-free; 4.ISO9001 Steel grating specification: Specifications of steel gratingsNoItemDescription1Bearing bar20x5, 25x3, 25x4, 25x5, ... engineering, Oil and grease chemistry, Agriculture husbandry, Horticulture, Steel industry, Waste disposal, Food processing, Aquatic breeding, ... treatment: Good rust-proof property, maintenance-free replacement. Anti-theft design: The cover and the ...