First, floor decking.
Also known as steel decking or profiled steel sheet, it is made of galvanized steel sheet through roll forming. Its cross-section is V-shaped, U-shaped, trapezoidal, or similar corrugated shapes. It is mainly used as permanent formwork, but can also be selected for other applications. During use, floor decking acts as tensile reinforcement in concrete slabs, increasing the slab’s stiffness and saving on steel and concrete usage. The embossed surface of the profiled sheet maximizes the bond between the floor decking and the concrete, forming a unified structure. Combined with stiffening ribs, this gives the floor decking system high load-bearing capacity. Profiled steel sheet composite slabs (floor decking, steel decking) are a highly rational structural form. They fully utilize the advantages of the tensile strength of steel and the compressive strength of concrete, taking advantage of the location and characteristics of each component, and also possess good seismic performance and construction performance. This structure is currently widely used in multi-story and high-rise buildings both domestically and internationally. Comparison of Floor Decking and Ordinary Reinforced Concrete Slabs:
1. Floor decking can serve as a permanent formwork for cast-in-place concrete, eliminating the need for formwork installation and removal during construction.
2. After installation, floor decking can be used as a construction platform, and since temporary supports are unnecessary, it does not interfere with work on the next floor.
3. Floor decking can be used as the bottom reinforcement of the floor slab, reducing the workload of installing slab reinforcement.
4. Depending on the different interface shapes of the profiled steel sheet, up to 30% of the concrete usage in the floor slab can be reduced. Reducing the slab’s self-weight allows for a corresponding reduction in the dimensions of beams, columns, and foundations, improving the overall structural performance.
Second, I beams.
I-beams, also known as steel beams, are long steel bars with an I-shaped cross-section. Their specifications are expressed in millimeters as web height (h) * flange width (b) * web thickness (d), such as “I-160*88*6,” which indicates an I-beam with a web height of 160 mm, a flange width of 88 mm, and a web thickness of 6 mm. I-beams are divided into three types: ordinary I-beams, lightweight I-beams, and H-beams. Ordinary I-beams and lightweight I-beams have flanges that gradually thin from the root towards the edge at a certain angle. Because their cross-sectional dimensions are relatively high and narrow, the moments of inertia about the two principal axes of the cross-section differ significantly. Therefore, they are generally only used for members subjected to bending within the web plane or for forming lattice-type load-bearing members. They are not used for axially compressed members or members subjected to bending perpendicular to the web plane, which greatly limits their application range. I-beams are widely used in various building structures, bridges, vehicles, supports, machinery, etc.
Thirdly, C-shaped steel
C-shaped steel is produced by cold bending of hot-rolled steel sheets and is automatically processed by C-shaped steel forming machines. It has thin walls, light weight, excellent cross-sectional properties, and high strength. Compared with traditional channel steel, it can save 30% of material for the same strength. C-shaped steel purlins are available in five specifications according to height: 80, 100, 120, 140, and 160 mm. The length can be determined according to the engineering design, but considering transportation and installation conditions, the total length generally does not exceed 12 meters. C-shaped steel is widely used in purlins and wall beams of steel structure buildings, and can also be assembled into lightweight roof trusses, brackets, and other building components. In addition, it can be used for columns, beams, and arms in machinery and light industrial manufacturing.
Fourth, H beam
H-shaped steel is an economical steel material with superior cross-sectional mechanical properties, optimized from I-beams. It is named for its cross-section resembling the letter “H”. H-shaped steel is divided into wide-flange H-beams (HW), medium-flange H-beams (HM), narrow-flange H-beams (HN), thin-walled H-beams (HT), and H-beams (HU). H-shaped steel is a new type of economical building steel. Its cross-sectional shape is economical and reasonable, with good mechanical properties. During rolling, the elongation at various points on the cross-section is more uniform, and the internal stress is lower. Compared with ordinary I-beams, it has the advantages of a larger section modulus, lighter weight, and metal savings, which can reduce the weight of building structures by 30-40%. Furthermore, because its flanges are parallel on the inside and outside and the flange ends are at right angles, it can save up to 25% of welding and riveting work when assembled into components. H-beams are commonly used in large buildings requiring high load-bearing capacity and good cross-sectional stability, such as supports and foundation piles.
Advantages of H-beams:
(1) Wide flanges result in high lateral stiffness and strong bending resistance.
(2) Parallel flange surfaces simplify connection, processing, and installation.
(3) Compared to welded I-beams, H-beams are lower in cost, higher in precision, and have less residual stress. They eliminate the need for expensive welding materials and weld inspection, saving approximately 30% in steel structure manufacturing costs.
(4) Under the same cross-sectional load, hot-rolled H-beam structures are 15%-20% lighter than traditional steel structures.
(5) Compared to concrete structures, hot-rolled H-beam structures can increase usable area by 6% while reducing structural weight by 20%-30%, thus reducing internal forces in structural design.
(6) H-beams can be processed into T-beams, and cellular beams can be combined to form various cross-sectional shapes, greatly satisfying engineering design and manufacturing needs.
Fifth, the differences between H-beams (HW, HM, HN) and H-sections.
H-beams have variable cross-section flanges, thicker near the web and thinner at the edges; H-sections have uniform cross-section flanges. HW, HM, HN, and H are general terms for H-sections. H-sections are welded; HW, HM, and HN are hot-rolled. HW H-sections have roughly equal height and flange width, mainly used as steel core columns in reinforced concrete frame structures, also known as stiffened steel columns; primarily used as columns in steel structures. HM H-sections have a height-to-flange width ratio of approximately 1.33 to 1.75, mainly used in steel structures as steel frame columns or frame beams in frame structures subjected to dynamic loads; for example, equipment platforms. HN (High-N) steel refers to H-beams where the height-to-flange width ratio is greater than or equal to 2, primarily used for beams. I-beams have similar applications to HN steel.
1. I-beams, whether standard or lightweight, have relatively high and narrow cross-sections, resulting in a significant difference in the moments of inertia about their two principal axes. Therefore, they are generally only suitable for components subjected to bending within their web plane or for forming lattice-type load-bearing members. They are unsuitable for axially compressed members or members subjected to bending perpendicular to the web plane, greatly limiting their application.
2. H-beams are high-efficiency and economical cross-section profiles (others include cold-formed thin-walled steel and profiled steel sheets). Due to their rational cross-sectional shape, they allow steel to perform more efficiently and improve load-bearing capacity. Unlike standard I-beams, H-beams have widened flanges, and their inner and outer surfaces are usually parallel, facilitating connections with other components using high-strength bolts. They offer a reasonable series of sizes and a complete range of models, making them convenient for design selection.
3. H-beams have flanges of uniform thickness and come in both rolled and welded sections. I-beams are always rolled, but due to inferior manufacturing processes, the inner edges of the flanges have a 1:10 slope. The rolling process for H-beams differs from that of ordinary I-beams, which use only one set of horizontal rolls. Because their flanges are wider and have no slope (or a very small slope), an additional set of vertical rolls is required for simultaneous rolling. Therefore, their rolling process and equipment are more complex than ordinary rolling mills. The maximum height of rolled H-beams that can be produced domestically is 800mm; anything exceeding this must be a welded composite section.
Sixth, Square Tubes.
Square tubes are hollow, square-section, lightweight, thin-walled steel pipes, also known as cold-formed steel profiles. They are made from Q235 hot-rolled or cold-rolled strip steel or coils, cold-bent into shape, and then high-frequency welded to form a square cross-section. Hot-rolled extra-thick-walled square tubes, except for the increased wall thickness, achieve corner dimensions and edge straightness that meet or even exceed the level of resistance-welded cold-formed square tubes. They possess excellent comprehensive mechanical properties, weldability, cold and hot working performance, and corrosion resistance, as well as good low-temperature toughness. Square tube performance:
1. Plasticity: Plasticity refers to the ability of a metallic material to undergo plastic deformation (permanent deformation) without breaking under load.
2. Hardness: Hardness is an indicator of the softness or hardness of a metallic material. Currently, the most commonly used method for measuring hardness in production is the indentation hardness test. This involves pressing an indenter of a specific geometric shape into the surface of the tested metallic material under a certain load, and determining the hardness value based on the degree of indentation. Commonly used methods include Brinell hardness (HB), Rockwell hardness (HRA, HRB, HRC), and Vickers hardness (HV).
3. Fatigue: The strength, plasticity, and hardness discussed above are mechanical property indicators of metals under static loads. In reality, many machine parts operate under cyclic loads, under which conditions fatigue occurs.
4. Impact Toughness: A load acting on a machine part at a very high speed is called an impact load. The ability of a metal to resist failure under an impact load is called impact toughness.
5. Strength: Strength refers to the property of a metallic material to resist failure (excessive plastic deformation or fracture) under static load. Since loads can be applied in the form of tension, compression, bending, and shear, strength is also divided into tensile strength, compressive strength, bending strength, and shear strength. There are often certain relationships between various strengths, but tensile strength is generally used as the most basic strength indicator in practice.
Square tubes are used in construction, machinery manufacturing, steel construction projects, shipbuilding, solar power generation supports, steel structure engineering, power engineering, power plants, agricultural and chemical machinery, glass curtain walls, automobile chassis, airports, boiler construction, highway guardrails, building construction, pressure vessels, oil storage tanks, bridges, power station equipment, lifting and transportation machinery, and other welded structural components with high loads.
Seventh, Round Tubes
Steel materials with open ends and a hollow concentric circular cross-section, whose length is greater than its perimeter. The specifications of round pipes are expressed by their external dimensions (such as outer diameter or side length), inner diameter, and wall thickness. Their size range is very wide, from very small capillary tubes to large round steel pipes with diameters of several meters. Round pipes can be used in piping, thermal equipment, the machinery industry, oil and geological drilling, containers, the chemical industry, and for special purposes. Commonly used structural round steel bars vary in size and application; smaller ones are used for decorative components, roof trusses, supporting components, space frames, and pipe trusses, while larger ones can be used for steel pipe concrete columns in heavy steel plants, pipe trusses in large stadiums, etc. Another major application of round steel bars is process piping, but this generally requires special materials and corrosion protection.
Post time: May-06-2026