... , BS4592, AS1657, JS3101 1.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3, 25X4, 25X4 ... type, plain I type, serrated type, serrated I type; cross bar: round type and square twisted type. Square twisted cross bars are ... mostly used.And round cross bars are normally used for fine-mesh steel gratings ...