Penetrating interlock 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 penetrates into the just top of the bearing flat steel and becomes interlocked after the twisting. It is light in dead weight, beautiful in appearance and smooth on the surface. It bears bi-directional load. It can serve as the ditch cover plate, ventilated grating cover plate, rainwater grate, all kinds of walkway slabs, suspended ceilings, the isolated plates at the entrances and exits, vessel deck, sea drilling platform, and industrial equipment platform.  The bearing flat steel is 2.0～5.0mm in thickness and 30～100mm in width.