... /NAAMM-MBG531, BS4592, AS1657, JS31011.3 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 ... ends welded with angle steel, so no need pre-embedded supporting part. 2.3 Security type of Drainage/Ditch Cover Both ...