... BS4592, AS1657, JS31011.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3, 25X4, 25X4.5, 25X4 ... and dimension is not limited to above.1.4 Grating type: flat bar: plain type, plain I type, serrated type, ... treatment: a. Galvanized, b. Untreated (black self-color), c. Painted 2. design can be customized according to site requirement. steel grating