Hot rolled I-beam, also known as I-shaped steel or steel beam, is a long strip of steel with an “I”-shaped cross section. It is one of the most traditional and widely used structural steel profiles in construction and engineering projects.

Key Differences from H-Beam

Although I-beam and H-beam look similar in appearance, they differ significantly in cross-sectional geometry, manufacturing process, and application:

1. Flange Design — The most fundamental difference: I-beam flanges have a taper on the inner surface, typically around 1:6 slope (thicker near the web, thinner at the edges). H-beam flanges are parallel with no slope (or very minimal).
2. Manufacturing Process — I-beams are produced with a single set of horizontal rolls, while H-beams require universal mills with both horizontal and vertical rolls for more precise shaping.
3. Section Performance — Due to the tapered flanges, I-beams have significant differences in moment of inertia between the two principal axes, making them suitable mainly for bending in the web plane. H-beams, with parallel flanges and wider sections, offer superior bi-directional bending resistance and torsional performance.
4. Application — I-beams are primarily used as beams (horizontal members) for single-direction loading, while H-beams can serve as both columns and beams for multi-directional loading. I-beams are also gradually being replaced by H-beams in modern steel structures

Different Names Under Various Standards

The I-beam is known by different names across various international standards:

Steel I Beam Specifications：

Hot-rolled I-beam is produced from continuous casting square or rectangular billets, which are heated to over 1200°C in a reheating furnace before rolling. After heating, the billets are descaled by high-pressure water to remove surface oxide scale, then fed into rolling mills for multiple passes. Unlike H-beam, I-beam rolling uses a single set of horizontal rolls without vertical roll assistance. After rough rolling and finish rolling stages, the billet is gradually shaped into an I-shaped cross-section. The tapered inner flange slope (approximately 1:6) formed during rolling is a distinctive feature of I-beam. After rolling, the I-beam is cut into sections by a hot saw, cooled naturally on a cooling bed, then straightened on a straightening machine to ensure straightness and twist meet standard requirements. Finally, the I-beam is cut to customer-specified lengths by sawing, inspected, and bundled for storage.

I-beams are bundled by specification, length, and material grade before shipment, with each bundle typically weighing 5-8 tons, secured with high-strength steel strapping or wire. Special care must be taken during stacking due to the tapered flanges of I-beams to ensure flat stacking and prevent edge extrusion deformation. Wooden spacers or rubber pads can be placed between layers to prevent surface scratches. Each bundle is clearly labeled with specification, length, material grade, heat number, and customer information. I-beams are typically transported by bulk vessel or flat rack containers. Loading can be flexibly arranged according to beam lengths in 20-foot or 40-foot flat racks. Loading follows the principle of "heavy at the bottom, light on top," with wooden wedges or padding added to prevent movement during transit. For extra-long I-beams, protective sleeves can be fitted at both ends to prevent end impact damage. All transport solutions are optimized according to customer requirements and destination port conditions, ensuring safe, efficient, and economical delivery.

Hot-rolled I-beam is one of the most fundamental beam components in traditional steel structures, primarily used as load-bearing beams for single-direction bending loads. In industrial buildings, it is widely used for crane beams, roof trusses, secondary floor beams, and platform beams in workshops. In civil construction, it is commonly used for floor support beams and stair stringers in residential buildings. In bridge engineering, it is used for deck beams and cross beams of small and medium-span bridges. In machinery manufacturing, I-beams are commonly used for equipment bases, crane rail beams, and conveyor supports. In vehicle manufacturing, they are used for railway wagon underframes and heavy flatbed trailer beams. Compared with H-beam, I-beams are primarily used as beam members for single-direction loading. H-beams, on the other hand, are more suitable as steel columns bearing multi-directional loads. In modern large-scale construction, H-beams are gradually replacing I-beams for primary structural members, but I-beams still maintain cost advantages in small and medium-sized projects and maintenance work. With mature manufacturing processes and reliable mechanical properties, I-beams remain indispensable structural materials in many traditional steel structure projects.