... board with ventilation, lighting, cooling, non-slip, explosion-proof performance, etc.galvanized steel gratingApplication Specification Load Bearing Flat Bar sizeThickness≥3mm, depth ≥19mm19X3 ... .5, 25X4.7, 25X5…..40X6, 40X8, 40X10,….90X6….Pitch of Load bearding flat bars(mm)12.5,15, 20, 30, 30 ...