Steel used to manufacture engineering structures that bear loads is also called building structural steel.Structural steel is steel that meets specific strength and formability grades. Formability is expressed as elongation after interruption in a tensile test. Structural steel is generally used for load-bearing applications where the strength of the steel is an important design criterion.The performance requirements for this type of steel are mainly sufficient strength to ensure that it does not produce permanent deformation and damage during use. In addition, this type of steel often needs to be cut, bent, riveted and welded during use, so it is also required to have good formability and weldability. The carbon content of this type of steel is generally less than 0.30%, and most of them are rolled into steel sections (such as angle steel, channel steel, I-beam, threaded steel, etc.), steel plates and steel pipes with a certain cross-sectional shape. They are often used in engineering structures such as ships, vehicles, containers, lifting and transportation machinery, and in construction projects, they are used to manufacture bridges, steel columns, steel beams, trusses, etc. Engineering steel can be divided into two categories: ordinary carbon steel and low-alloy high strength steel.
Alloy structural pipe
