ISO 630-3 is the third part in the multi-series of International Standards on ‘Steels for structural purposes’. ISO 630‑3 specifies requirements for flat and long products of hot-rolled weldable fine-grain structural steels in the as-rolled (for SG grades only), normalized/normalized rolled and thermomechanical processed delivery conditions. ISO 630-3 applies to steel plates rolled on a reversing mill, wide flats, hot-rolled sections and bars, which are intended for use in heavily loaded parts of welded or bolted structures.
ISO 630‑3 covers 13 grades and 6 qualities.
The steels specified in ISO 630‑3 apply to hot-rolled plates, wide flats, sections and bars with a minimum nominal thickness of 3 mm and a maximum nominal thickness of 250 mm.
ISO 630‑3 on fine-grain structural steels is relevant to:
Fine-grain structural steel, as the names suggests, is steel that has fine grain structure due to low carbon content and alloying elements. The finer the grain size, the higher is the yield strength.
ISO 630‑3 provides information on classification and designation of grades and qualities of the steel, steelmaking process, delivery condition, chemical composition, mechanical properties and the surface condition required to manufacture and produce products from fine-grain structural steel.
Compliance to ISO 630-3 will equip you with best practice guidance on ensuring greater formability and workability of fine-grain structural steel and make the right choice for your specific engineering needs. Incorporating a standardised process will also aid in improved product development and stringent quality control measures.
ISO 630‑3 cancels and replaces the first edition (ISO 630‑3:2012), which has been technically revised. The main changes compared to the previous edition are as follows:
ISO 630-3