What an I-Beam Is
An I-beam is a structural steel section with an I-shaped cross-section, in which the flanges are narrower than the web height and taper slightly on the inner faces. This classic profile has been used for over a century because it carries bending loads efficiently and is simple to connect in frames.
I-Beam and H-Beam Profiles
I-beams have a taller web and narrower flanges, giving high strength in the direction of the web, while H-beams have wider parallel flanges for better performance in both directions. The two profiles are selected according to the loading direction: I-beams are economical for beams spanning between supports, and H-beams are preferred for columns.
The Q235 Grade
Q235 is the general structural carbon steel to GB/T 700 with a minimum yield strength of 235 MPa. It offers good weldability, formability and predictable mechanical properties, and is the most widely used grade for building frames and general steel fabrication in many markets.
Standard Sizes and Delivery
I-beams are supplied in standard sizes from about 100 mm to 500 mm in section height, with flange width and web thickness matched to the load. Sections are delivered in lengths of 6 m and 12 m or cut to the required length, with dimensional and material certificates.
Applications
Floor beams and roof beams in steel-framed buildings.
Support beams for platforms, gantries and walkways.
Members for fabricated frames and machine structures.
Beams for bridges, trestles and industrial structures.
Frequently Asked Questions
Q: What is the difference between an I-beam and an H-beam?
An I-beam has a taller web and narrower tapered flanges, while an H-beam has wider parallel flanges that suit both bending and column loading.
Q: What does Q235 mean?
Q235 is a structural steel grade to GB/T 700 whose number indicates a minimum yield strength of 235 MPa.
Q: Can I-beams be welded and bolted?
Yes, the carbon steel grade is readily weldable, and the web and flanges provide surfaces for bolted connections.
Q: What lengths are available?
Standard lengths are 6 m and 12 m, and custom lengths can be cut before delivery.
Q: Are the beams supplied with certificates?
Yes, mill test certificates are provided with each delivery.