How to Mark Stainless Steel？

1.Expression Methods of the Stainless Steel

①Use international chemical element symbols and national symbols to indicate chemical ingredients, and use Arabic letters to indicate ingredient content:

Such as: China, Russia 12CrNi3A

②Use fixed-digit numbers to represent steel series or numbers; such as: United States, Japan, 300 series, 400 series, 200 series;

③Use Latin letters and sequence to form the serial number, which only indicates the application.

2.The Numbering Rules of the Stainless Steel

①Use element symbols;

②Chinese Pinyin, open-hearth steel: P; boiling steel: F; killed steel: B; Class A steel: A; T8: Special 8; GCr15: ball.

◆Combined steel, spring steel, such as: 20CrMnTi 60SiMn, (C content expressed in parts per ten thousand).

◆Stainless steel and alloy tool steel (C content expressed in thousandths), such as: 1Cr18Ni9 thousandth (i.e. 0.1%C), stainless C≤0.08% such as 0Cr18Ni9, ultra-low carbon C≤0.03% such as 0Cr17Ni13Mo.

3.Labeling Method of Stainless Steel in the United States

The American Iron and Steel Institute uses three digits to designate various standard grades of wrought stainless steel:

①Austenitic stainless steel is marked with 200 and 300 series numbers. For example, some of the more common austenitic stainless steels are marked with 201, 304, 316 and 310.

②Ferritic and martensitic stainless steel are represented by 400 series numbers. Ferritic stainless steel is marked with 430 and 446, martensitic stainless steel is marked with 410, 420 and 440C, dual phase (austenite-ferrite).

③Stainless steel, precipitation hardened stainless steel and high alloys with an iron content of less than 50% are usually named after patented names or trademarks.

Stainless Steel Grade Comparison Table