What is the difference between S30408 and 304 in seamless stainless steel tubes?
S30408 is the UNS number system identifier for one type of austenitic stainless steel, with S30400 being the corresponding UNS number for 304.
The UNS numbering system specifies 18 series for metals and alloys, with each UNS number consisting of a single letter prefix followed by five Arabic digits. In most cases, the letter represents the metal property, such as stainless steel is represented by "S."
304 is a grade designation for Cr-Ni Austenitic 300 series stainless steel. The percentage of Cr-Ni varies, with corresponding grade designations including 304, 316, 321, and so on. Therefore, S30408 is the name given to a specific stainless steel material with a particular percentage of Cr-Ni in the numbering system. They are merely different identification methods.
