This standard specifies the order information, dimensions, shape, mass, and tolerances, technical requirements, test methods, inspection rules, packaging, marking, and quality certificate for hot-rolled I-beams, hot-rolled channels, hot-rolled equal angles, and hot-rolled unequal angles. This standard applies to hot-rolled equal angles, hot-rolled unequal-leg angles, hot-rolled I-beams, and hot-rolled channels with taper flanges (hereinafter referred to as section steel).
Q235 B/C
Q355 B/C/D/E
Q420 B/C/D
Q460C/D
GB/T 1591-2024(Steel Grade)
As a low-alloy high-strength structural steel, Q355B demonstrates excellent weldability and comprehensive mechanical properties, making it one of the most widely used steel grades in China for structural engineering and construction projects. GB/T 1591 Q355B (formerly Q345B) offers an optimum combination of high yield strength, good ductility, and reliable impact toughness at room temperature. It is commonly used in welded structures, bolted and riveted connections for buildings, bridges, industrial plants, transmission towers, and heavy machinery. Its versatility in various thicknesses and delivery conditions (as-rolled, normalized, TMCP) makes it a preferred grade for both general and critical structural applications.
