... parking lot etc.3) steel grating may be applied to platform, floor, walkway, stair treads, trestle, fencing, ... drainage, trench cover, pit cover, suspended ceiling, ventilates and light through facility, etc.4) category: 1.plain steel ... bar pitch38,50,80,100mmmaterialLow carbon steel, stainless steel, aluminumSurface treatmentUntreated, hot galvanized, ...