... -MBG531, BS4592, AS1657, JS3101 1.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3, 25X4 ... …..40X6, 40X8, 40X10,….90X6….Pitch of Load bearding flat bars(mm)12.5,15, 20, 30, 30.6, 32.5, 34, 34 ... dimension is not limited to above. 1.4 Grating type: flat bar: plain type, plain I type, serrated type, serrated I ...