... MBG531, BS4592, AS1657, JS3101 1.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3 ... , 25X5…..40X6, 40X8, 40X10,….90X6….Pitch of Load bearding flat bars(mm)12.5,15, 20, 30, 30.6, 32 ... 34.8, 35.3, 40, 60, 80……Pitch of cross bars(mm)38.1, 50, 50.8, 70, 75, 80 ... is not limited to above. 1.4 Grating type: flat bar: plain type, plain I type, serrated type, ...