H-beams used as columns and beams differ in design to optimize load-bearing for their respective roles:
Columns (Vertical Load-Bearing):
Columns prioritize axial compression resistance, leading to symmetrical cross-sections with equal flange width and height (e.g., HW 300×300 in Chinese standards). These "wide-flange" sections (denoted HW in GB/T 11263 or HEA in EN standards) have thick flanges (10–16mm) to prevent buckling under vertical loads. For example, a 50-story building column might use an HW 400×400 with a yield strength of 355MPa, capable of supporting 8,000+ tons of axial load.
Beams (Horizontal Load-Bearing):
Beams focus on bending resistance, featuring taller heights and narrower flanges (e.g., HN 500×200 in GB/T 11263 or IPE 300 in EN standards). The height increases the moment of inertia, reducing deflection under live loads, while narrower flanges save material and space for building services. A typical floor beam in a commercial building might span 8 meters with a HN 400×150, supporting 5 kN/m² of distributed load with less than L/250 deflection.
Design codes like AISC 360 specify minimum flange-to-web ratios to ensure stability: columns require wider flanges (flange width ≥ 1/3 height), while beams prioritize height for bending efficiency.
