Through grid plate (grating): the cross bar of this type of product is the flat steel with the smaller cross section. The cross section is generally no more than 1/2 of the bearing flat steel. It is pressed in from the just top of the bearing flat steel. It is beautiful in appearance and smooth on the surface. It bears bi-directional load and has strong bearing capacity, but it is very heavy in dead weight. It can serve as the ditch cover plate, ventilated grating cover plate, rainwater grate, all kinds of walkway slab, suspended ceilings, air separation filtration screen, vessel deck, sea drilling platform, and industrial equipment platform.  The bearing flat steel is 2.0～5.0mm in thickness and 20～100mm in width.