The standard for ordinary carbon structural steel is GB/T 700--2006.

Ordinary carbon structural steels have wide limits on carbon content, property range and content of phosphorus, sulfur and other residual elements. Ordinary carbon structural steel is divided into three categories: Class A steel (Class A steel) is steel that guarantees mechanical properties; Class B steel (Class B steel) is steel that guarantees chemical composition; Special steel (Class C steel) is both. Steel that guarantees both mechanical properties and chemical composition.

Usually Q195, Q215 and Q235 have low carbon content, good welding performance, plasticity and toughness, and a certain strength. They are usually used for rolling into thin plates, steel bars, welded pipes, low carbon steel wires, steel wire mesh, roof panels, etc. It is also used in bridges, Building and other structures or common parts bolts, rivets, tie rods and connecting rods, etc.

Q255 and Q275 have relatively high carbon content, high strength, good plasticity and toughness, and are usually rolled into shaped steel, steel strip and steel plate as structural parts or components, and can also be used as steel bars and railway fishplates.

According to some special performance requirements, the composition of ordinary carbon structural steel can be slightly adjusted to form a series of professional steels, such as riveting steel, bridge steel, pressure vessel steel, hull steel, boiler steel. In addition to strictly controlling chemical composition and ensuring conventional performance, professional steel also stipulates some special inspection items, such as low temperature impact toughness, aging sensitivity, gas in steel, inclusions and fractures.