... .1.1 Material Q235 , or other equivalent material1.2 Grating Conformity Standard: YB/T4001, ANSI/NAAMM-MBG531, BS4592, AS1657 ... , JS31011.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3, 25X4, 25X4.5, ... treatment: a. Galvanized, b. Untreated (black self-color), c. Painted 2. design can be customized according to site requirement. steel grating