Reinforcement refers to steel for reinforced concrete and prestressed reinforced concrete, which is circular in cross-section and sometimes square with rounded corners. Including plain round bars, ribbed bars, twisted bars. There are many types of steel bars, usually classified by chemical composition, production process, rolled shape, supply form, diameter, and use in structures. The steel bar for reinforced concrete refers to the straight or coiled steel used for reinforced concrete reinforcement, and its shape is divided into two types: smooth round steel bar and deformed steel bar. Steel bars mainly bear tensile stress in concrete. Due to the effect of the ribs, the deformed steel bar has a greater bonding capacity with the concrete, so it can better withstand the action of external forces

H-shaped steel is a new type of economical building. The section shape of H-shaped steel is economical and reasonable, and the mechanical properties are good. When rolling, the extension of each point on the section is relatively uniform and the internal stress is small. Compared with ordinary I-shaped steel, it has the advantages of large section modulus, light weight, and metal saving. The structure is reduced by 30-40%; and because the inside and outside of the legs are parallel, and the legs are at right angles, they can be assembled and combined into components, which can save welding and riveting workload by up to 25%. It is often used in large buildings (such as factories, high-rise buildings, etc.) that require large bearing capacity and good section stability, as well as bridges, ships, lifting and transportation machinery, equipment foundations, brackets, foundation piles, etc.

Welded steel pipe: also called welded pipe, is made of steel plate or steel strip after bending and then welding. According to the weld form, it is divided into straight seam welded pipe and spiral welded pipe. According to the purpose, it is divided into general welded pipe, galvanized welded pipe, oxygen blown welded pipe, wire casing, metric welded pipe, idler pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welded thin-walled pipe, electric welded special-shaped pipe and spiral welded pipe. Generally, welded pipes are used to transport low-pressure fluids. Made of Q195A, Q215A, Q235A steel. It can also be manufactured from other mild steels that are easy to weld. Steel pipes are subject to water pressure, bending, flattening and other tests, and have certain requirements for surface quality. Usually, the delivery length is 4-10m, and it is often required to deliver in fixed lengths (or double lengths). The specification of the welded pipe is indicated by the nominal diameter (mm or inch). The nominal diameter is different from the actual one. The welded pipe has two types of ordinary steel pipe and thickened steel pipe according to the specified wall thickness. The steel pipe is divided into two types: threaded and non-threaded according to the pipe end form.

The steel used to manufacture fasteners and connecting parts (such as bolts, nuts, screws, rivets, etc.) by cold heading processing method is called cold heading steel, commonly known as riveting screw steel. Cold heading is formed by metal plasticity at room temperature. Using the cold heading process to manufacture fasteners not only has high efficiency and good quality, but also saves materials and costs. However, the cold heading process has higher requirements on the quality of raw materials. For the deformation of cold heading steel, it is necessary to have the lowest possible resistance and the highest possible deformation capacity. Generally, the yield ratio of cold heading steel is required to be 0.5 to 0.65, and the reduction of area is greater than 50%. If the carbon content of the steel is greater than 0.25%, spheroidizing annealing heat treatment should be carried out to improve the cold heading performance of the steel. The standard stipulates that steel should be subjected to cold top test. It is required that the ratio of the height of the sample after cold upsetting before cold upsetting is high-grade; 1/4; relatively high-grade; 1/3; ordinary grade; 1/2. The general standard stipulates that it is 1/2.