S275JR is a non-alloy structural steel grade standardized under the European standard EN 10025. The alphanumeric designation "S275JR" provides key information about its fundamental properties:
'S' stands for "Structural steel."
'275' indicates the minimum specified yield strength (ReH) in megapascals (MPa) for material with a thickness of up to 16 mm. Therefore, this grade guarantees a yield strength of at least 275 MPa for standard thin sections. For thicker sections, this minimum value decreases as specified in the standard.
'J' signifies that the steel is tested for impact toughness (Charpy V-notch) at room temperature (+20°C).
'R' indicates that the steel is supplied in the as-rolled condition (a hot-rolled state without further heat treatment like normalizing).
This steel is characterized by its good weldability, cold-forming properties, and consistent mechanical performance, making it a workhorse material in general construction. It is commonly produced in forms such as steel plates, sheets, strips, and long products like H-beams, channels (e.g., PFC channels), and angles. Its primary application lies in welded, bolted, and riveted structures for buildings, bridges, industrial plants, and general machinery where high impact toughness at sub-zero temperatures is not a critical requirement.
The grade is part of a family; for instance, S275J0 is tested at 0°C, and S275J2 at -20°C, offering progressively better low-temperature toughness. S275JR is therefore the most basic quality grade suitable for ambient temperature applications. It finds a rough equivalent in the Chinese standard GB/T 700's Q275 grade. In material number systems, it is also known as 1.0044.