As modern construction and high-end equipment manufacturing continue to demand higher safety margins and durability, structural materials are required to deliver consistent mechanical performance under complex service conditions. EN 10210 hot-formed square tubes, known for their uniform cross-sectional properties, excellent toughness, and long-term reliability, are widely used in bridges, offshore structures, heavy industrial plants, and seismic-resistant buildings. This article clarifies what EN 10210 square tubes are, how they differ from seamless square tubes, and how to select them correctly for critical applications.