Flat bottomed steel silos are with large diameter and capacity, which is popular with its easy installation and low costs. There are many ways for unloading, such as free-flow unloading, multi-spots unloading and so on .We also can choose the concrete conical bottom to put the automatic-flow unloading into practice. The flat-bottom steel silos can be widely used in grain process and storage lines, some of them can be chosen to be used in oil, feed, flour, starch, brew, and port or grain storage industrial lines. Radial beam silo roof support system the roof is made of galvanizing board that is 0.8mm thick both battens and bolts are with galvanizing die. There are special equipments on the silo roof such as natural vent, manhole, roof ladders, and secure cages and so on. Silo bin: Body sheets are made of high quality galvanizing steel board; the sheets are bolted together with high tensile bolts. Galvanizing coating of body sheets is 275g/m2 or 350g/m2.Thickness of silo wall is designed according to the strength theory, which makes the wall afford even swelling tension. At the same time, the interior vertical stiffeners can afford the vertical friction It is 0.96m or 1.44m between every two stiffeners, the cutting face is in the shape of "z", and there are spherical waterproof washers in the bolts hole and waterproof mastic bars between every two pieces of silo sheet. We make manhole, ladders, door, safety cages, handrails on silos .