Shandong Zhongao Steel Co. LTD. is a large-scale iron and steel enterprise integrating sintering, iron making, steel making, rolling, pickling, coating and plating, tube making, power generation, oxygen production, cement and port. The main products include sheet (hot rolled coil, cold formed coil, open and longitudinal cut sizing board, pickling board, galvanized sheet), section steel, bar, wire, welded pipe, etc. The by-products include cement, steel slag powder, water slag powder, etc. Among them, fine plate accounted for more than 70% of the total steel production.The distinction between steel roof truss and steel grid truss is: The redundant material in the "beam" is hollowed out to form the "truss" structure, which is one-dimensional. The redundant materials in the "plate" are hollowed out to form a "grid" structure, which is two-dimensional. The excess materials in the "shell" are hollowed out to form a "mesh shell" structure, which is three-dimensional.In industrial plants, due to the needs of industry or traffic, the pillar on a certain shaft needs to be removed, so that the bracket should be set up in the position of a large opening to support the roof frame of the pillar. Brackets are mounted on poles at each end. Bracket is also called bracket beam because of the role of the beam. The truss supporting the middle roof truss is called bracket. The bracket generally adopts parallel string truss, and its belly rod adopts the herringbone system with vertical rod.