Structural Steel

Round steel is a type of smooth-surfaced, ribless cylindrical rebar with a uniform circular cross-section. Typically made from low-carbon or ordinary carbon steel, it offers good plasticity and toughness, making it easy to bend, tie, and weld. Due to the absence of surface ribs, its bonding with concrete relies primarily on friction, which makes it more suitable for components subjected to lower loads—such as tie columns, ring beams, and distribution bars in floor slabs—or as auxiliary reinforcement. In construction, round steel is commonly used as stirrups, connection bars, or reinforcement for temporary support structures. Compared with deformed rebar, round steel has slightly weaker mechanical interlocking with concrete, but its simplicity and ease of fabrication make it an essential basic steel material in building projects.

Deformed steel bar, also known as rebar, is a type of reinforcing steel featuring longitudinal and transverse ribs on its surface. These ribs—typically crescent-shaped, spiral, or herringbone—significantly enhance the bonding strength between the steel and concrete, allowing them to form an integrated structure that jointly resists external forces. As the "skeleton" of concrete structures, rebar plays a critical role in improving tensile and shear strength. Depending on material composition—such as ordinary hot-rolled rebar or thermomechanically treated rebar—and available in various grades and specifications, it meets a wide range of strength requirements for construction projects. Rebar is widely used in buildings, bridges, tunnels, water conservancy facilities, and other structural applications. Compared to plain round steel, the mechanical interlocking provided by the ribbed surface greatly enhances structural integrity and load-bearing capacity, making deformed rebar an indispensable material in modern civil engineering.

Steel plate is a flat steel product made from raw steel through processes such as rolling, forging, or casting. As one of the fundamental materials in modern industry and construction, it features high strength, good plasticity, and long-term durability. By adjusting its material composition (e.g., carbon steel, alloy steel, stainless steel) and manufacturing method (cold rolling or hot rolling), steel plates can be engineered to meet specific mechanical requirements such as compression resistance, tensile strength, and wear resistance.In terms of appearance, steel plates may present smooth surfaces, fine textures, or specialized coatings, offering both a solid metallic feel and dimensional stability. They are easily processed by cutting, welding, or bending into various shapes and forms. Steel plates are widely used in structural applications like machinery manufacturing and the automotive industry, as well as in architectural scenarios as curtain walls or decorative panels. With their crisp lines and robust presence, they create a strong visual contrast when paired with transparent materials such as glass, bringing industrial aesthetics, modernism, or refinement to architectural spaces.

Angle steel is a type of long steel with an L-shaped cross-section, typically produced by hot rolling or cold bending. It mainly comes in two types: equal angle steel (with equal side widths) and unequal angle steel (with different side widths). Its specifications are usually expressed as side width × side width × thickness in millimeters (e.g., 50×50×5). Featuring high bending resistance and structural stability, angle steel is easy to connect and install. Widely used in building structures such as steel beams and trusses, as well as in mechanical manufacturing, transmission towers, and bridge supports, angle steel can serve as a standalone load-bearing component or be assembled into various structural parts. It is one of the most commonly used structural steel materials in engineering due to its low cost, high strength, and ease of construction.

Channel steel is a type of long steel with a groove-shaped cross-section, typically processed through hot rolling or cold bending. Its cross-section resembles the shape of "[", consisting of a web and two flanges on either side. Based on manufacturing processes, it can be classified into hot-rolled channel steel (such as the [20 model in GB/T 706) and cold-formed channel steel (such as C-channel). Specifications are expressed as web height × flange width × web thickness (e.g., [100×48×5.3). Channel steel features high unidirectional bending resistance and ease of assembly and connection. It is widely used in building steel structures (beam-column systems, industrial roof frames), mechanical manufacturing (equipment frames), and vehicle and ship construction (frame structures). It can function as an individual load-bearing component or be welded into composite cross-section members such as I-beams or box columns, making it a vital material for structural support and load-bearing in engineering applications.

I-beam steel is a type of hot-rolled long steel with an I-shaped cross-section, consisting of parallel upper and lower flanges connected by a vertical web, forming an efficient mechanical structure. Based on flange width, it is classified into standard I-beams (e.g., I20a) and wide-flange H-beams (e.g., HW200×200). Specifications are expressed as web height × flange width × web thickness (e.g., I250×116×8). Its unique cross-sectional design provides good bending resistance and structural stability in the vertical direction while maintaining a relatively light weight horizontally. The material distribution aligns with engineering mechanics principles. I-beam steel is primarily used in load-bearing scenarios such as main beams in building structures, columns in industrial buildings, and bridge frameworks. It can also be combined to form larger load-bearing assemblies. As a key load-bearing component in steel structure engineering, it offers high load efficiency, convenient installation, and good cost-effectiveness.

Round steel pipe is a type of pipe with a hollow circular cross-section. According to the manufacturing process, it can be classified into seamless steel pipes (produced by hot rolling or cold drawing through perforation) and welded steel pipes (formed by rolling and welding steel plates). Its specifications are expressed as outer diameter × wall thickness (e.g., Φ50×3mm). It features isotropic stress distribution, outstanding torsional resistance, and high cross-sectional efficiency. Round steel pipes are widely used in building structures (such as space trusses and truss joints), mechanical manufacturing (hydraulic cylinders, drive shafts), fluid transportation (oil pipelines, water supply and drainage systems), and municipal engineering (guardrail supports, light poles). They can serve as individual load-bearing components or be assembled into complex spatial structures via intersecting welds. Combining structural efficiency with economic advantages, round steel pipe is one of the most commonly used pipe types in modern engineering.

Rectangular and square steel tubes are hollow steel pipes with square or rectangular cross-sections, typically produced through hot rolling or cold bending and welding processes. Based on shape, they can be divided into square tubes (equal length and width, e.g., 50×50×3mm) and rectangular tubes (unequal length and width, e.g., 60×40×2.5mm). These pipes feature large moment of inertia, good bending and torsional resistance, and smooth surfaces that facilitate easy connection. They are widely used in building steel structures (columns, curtain wall frames), machinery manufacturing (equipment frames), decorative projects (guardrails, display racks), and transportation (vehicle frames). Square and rectangular tubes can function as independent load-bearing components or be welded into grid structures. Their sharp-edged appearance not only meets structural load requirements but also aligns with modern architectural aesthetics, making them essential materials in contemporary steel structure engineering and industrial manufacturing.

Special-shaped steel tubes refer to steel pipes with cross-sections that deviate from conventional shapes like circles or squares. They are typically produced through cold bending, welding, or hot extrusion processes, and come in a variety of cross-sectional forms such as oval, triangular, trapezoidal, D-shaped, and hexagonal tubes. These pipes combine structural functionality with aesthetic appeal—while meeting specific mechanical performance needs (e.g., directional bending resistance or anisotropic loading), they also serve design and assembly requirements in architecture and machinery. Special-shaped steel tubes are widely used in areas with unique shape demands, including architectural curtain walls (decorative elements), furniture manufacturing (frame structures), automotive industry (vehicle skeletons), and stage equipment (truss systems). They can serve both as load-bearing structural components and decorative features, embodying the modern engineering principle that "form follows function." As such, they represent both a functional extension and an aesthetic upgrade of traditional steel tubing.