GB/T 221-2008 Active

This standard specifies the method of designating the grades of steel products. This standard applies to the designation of grades of pig iron, carbon structural steel, low-alloy structural steel, high-quality carbon structural steel, easy-cutting steel, alloy structural steel, spring steel, tool steel, bearing steel, stainless steel, heat-resistant steel, welding steel, cold-rolled electrical steel, electromagnetic pure iron, raw pure iron, high-resistance electric heating alloys, and related special steels. For the method of designating the grades of steel products that are not specified in this standard, the grades shall be designated in accordance with the principles specified in this standard. The method of designating the grades of powder metallurgy materials, cast iron (parts), cast steel (parts), iron alloys, high-temperature alloys and high-temperature materials of intermetallic compounds, corrosion-resistant alloys, and precision alloys shall comply with the provisions of the following national standards, respectively.