... bar pitch;50,100mm 3>Plain,Serrated,I-shape 4>Hot-dipped galvanized,Painted,Untrea Product 1.ISO9001:2008 management 2 ... 'x12', 3'x20', 3'x24'.6.Surface Treatment: Bare, Paint and Hot Dipped Galvanized.7.There are three kinds of steel gratings ... & safety compared with plain grating.I-Shape:lighter,more economical and practical compared with plain grating.