... cover grating) ISO9001 high technology rich experience quick shipment well cover grating(trench cover grating,drain cover grating) ... GratingApplication: flooring walkway, platform and steel structures, stair tread, well cover, trench cover, compound gratings, storage shelves, ladder, ... omitted)P-paintingU- untreatedBearing bar shapeF- plain surface (F is usually can be omitted)S-serrated surfaceI-the ...