Abstract
Mechanical properties of cold roll-formed and press-formed steel square pipes are reviewed on the basis of numerous past experimental data. Major view points are strength, elongation, and notch toughness, which are related with the buckling and fracture behaviors of steel members in buildings excited by a strong earthquake. The increase in strength, the decrease inelongation, and the lack in notch toughness attributed to cold-forming processes are quantitatively and statistically demonstrated, based on which necessary design and fabrication remarks are provided, and future research needs are clarified.