1. Universal Rolling of H-Beams
Hot rolled H-beams are produced on universal mills where the section passes through a series of four roll stands, with two horizontal rolls forming the flanges and two vertical rolls forming the web. This arrangement allows the web and flange thicknesses to be adjusted independently, and the beam is rolled in several passes until the final section is reached. The process gives accurate dimensions, a smooth surface and a consistent grain flow, and modern mills control the rolling temperature to refine the microstructure of the finished section.
2. Welded Built-Up Sections
Where the required depth or weight is outside the standard rolling range, H-beams are built up by welding flange plates to a web plate. The plates are cut to width, the web is prepared with edge profiling, and the three plates are welded together with submerged arc welding on automated stations. This route produces beams with a depth of 1000 mm or more and is used for heavy crane girders, bridge girders and columns with high load capacity. The welding parameters are monitored continuously to keep the weld quality consistent along the full length.
3. Material Control and Traceability
Every beam is made from steel with a verified heat number, and the plate or bloom is checked against the mill certificate before production. The steel grade, the chemical analysis and the mechanical test results follow the beam through rolling or welding, so each finished section can be traced back to its source heat. For welded sections, the flange and web plates are marked with the heat number and the weld consumable batch is recorded in the production file.
4. Inspection and Testing
Finished beams are checked for dimensions, straightness, camber and twist against the tolerance standard, and the surface is inspected for defects. Tensile and Charpy impact tests are taken from the same heat to verify the mechanical properties, and welded sections are tested by ultrasonic examination of the weld zone. For critical applications, a 3.1 or 3.2 certificate to EN 10204 is issued with the mechanical and chemical data for the delivered beams.
5. Specialized Beam Variants
Fire resistant steel beams with controlled high temperature strength.
Weathering steel beams for unpainted outdoor structures.
Tapered beams for roof profiles with variable depth.
Castellated beams cut and re-welded for service openings and lower weight.
Beams with pre-camber for long span floors and girders.
Frequently Asked Questions
Q: What is the difference between rolled and welded H-beams? Rolled beams are formed in one piece on a universal mill, while welded beams are built from three plates joined by submerged arc welding, which allows larger and non-standard sizes.
Q: How accurate are the dimensions of hot rolled beams? The dimensional tolerances follow the applicable standard such as EN 10034, covering depth, flange width, thickness, straightness and length.
Q: Why is ultrasonic testing used on welded beams? Ultrasonic examination detects internal defects in the weld zone, such as lack of fusion or porosity, that cannot be seen on the surface.
Q: Can the beam be supplied with pre-camber? Yes, beams can be cambered during production so that the dead load deflection is compensated and the finished floor is straight under service load.
Q: What does a 3.1 certificate mean? A 3.1 certificate to EN 10204 is issued by the manufacturer based on tests performed on the delivered batch, and it documents the chemical and mechanical properties of the material.