What material category does foreign standard UB steel belong to?

Foreign standard UB (Universal Beam) steel, primarily specified in European standards, is classified as non-alloy or low-alloy structural steel. The most common grade is S355JR (per EN 10025-2), a non-alloy structural steel, while higher-performance variants like S355NL (low-alloy, normalized) are used for demanding applications. UB steel's material category prioritizes balanced strength, ductility, and weldability-critical for load-bearing roles in construction (e.g., building frames, bridges) and industrial machinery. Unlike specialized steels (e.g., stainless steel), UB steel is cost-effective, making it suitable for large-scale structural projects. Its non-alloy/low-alloy composition ensures compatibility with standard fabrication processes (cutting, bending, welding) without requiring specialized heat treatment, simplifying on-site installation.