... BS4592, AS1657, JS3101 1.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3, ... .5,15, 20, 30, 30.6, 32.5, 34, 34.8, 35.3, 40, 60, 80……Pitch of cross ... not limited to above. 1.4 Grating type: flat bar: plain type, plain I type, serrated type, serrated ... I type; cross bar: round type and square twisted type. Square twisted cross ...