What does GB/T 706-2016 specify for I-beam dimensions?

GB/T 706-2016 (China's standard) defines hot-rolled I-beam dimensions, including height (100-630mm), flange width (68-180mm), and thickness (4.5-17mm). It specifies tolerances: ±1.5% for height, ±2% for flange width, and ±0.7mm for thickness. The standard also lists section properties like moment of inertia and weight per meter (e.g., 10# I-beam: 100mm height, 11.261 kg/m). It covers both ordinary (IPE-like) and heavy-duty series, with heavy I-beams having thicker flanges for higher load capacity. Compliance ensures interchangeability in construction, allowing engineers to use standardized designs across projects.