S355JR Steel Grade Overview

S355JR is a non-alloy structural steel widely used in construction and engineering applications. It offers medium to high strength, good toughness, and excellent weldability, making it suitable for demanding load-bearing structures. As a European EN 10025-2 grade, S355JR is known for its balance of strength and workability.

Chemically, S355JR typically contains carbon (≤0.24%), manganese, silicon, phosphorus, and sulfur within controlled limits. These elements contribute to its mechanical strength, while maintaining good ductility and forming properties. The “JR” designation indicates that the steel has undergone Charpy V-notch testing at room temperature (20°C), ensuring reliable impact resistance.

S355JR is commonly delivered in conditions such as hot rolled, normalized rolled, or thermomechanically rolled. These delivery states help optimize its grain structure and mechanical performance for various fabrication needs including welding, cutting, and bending.

Its wide application range includes building structures, bridges, transmission towers, steel frames, machinery parts, and general engineering components. Due to its reliability and strength, S355JR is often chosen for infrastructure projects where safety and stability are essential.