... :30,40,60mm 2>Cross bar pitch;50,100mm 3>Plain,Serrated,I-shape ... heavyduty, well resistance of strong impact on surface. Gratings with cross bar centers at 50mm can bear lateral impact well. This ... w-4, 19-w-2, 15-w-2 etc. 3Twisted Cross Bar Pitch38.1, 50, 60, 76, 80, 100, 101. ... size,different shape,different standard,and any special requirements with different bearing capacity and span.In this case, the ...