... ANSI/NAAMM-MBG531, BS4592, AS1657, JS31011.3 Grating Dimension Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3,19X5,20X3, 20X5, 25X3 ... , 25X4, 25X4.5, 25X4.7, 25X5…..40X6, 40X8, 40X10,….90X6….Pitch of Load bearding flat ... not limited to above.1.4 Grating type: Bearing bar: Plain type, Plain I type, Serrated type, Serrated I type; Cross bar: Round cross bar, ...