SUS 304 Austenite stainless steel is usually referred to as the Japanese name for SS304 or AISI 304 stainless steel. There is no major difference except that the two grades are referred in Japanese and American grades. Some people although try to explain the difference in terms of mechanical properties.
A sample of SUS304 stainless steel from a Japanese source was collected, and a sample of AISI 304 (SS304) stainless steel from an American source is taken. Both samples are sent in a mechanical lab for testing. The comparative analysis of mechanical properties of SUS304 and SS304 stainless steel is shown in below table.
|Mechanical Properties||SUS304 Steel||SS304 Steel|
|Tensile Strength (Mpa)||520||495|
|Yield Strength (Mpa)||240||230|
Read details about SUS304 in main article: JIS G4303 SUS304 Austenite Stainless Steel Grade
As you can check from the above-tested results, both of the grades have shown incredibly closer results due to which it can be easily concluded that SS304 and SUS304 stainless grades are same as per chemical and mechanical properties. The only difference is the standardization of the two material grades in different nation states.
Therefore both materials SS304 and SUS 304 steel can be used alternatively provided there aren’t any explicit regulatory requirements by the state or contractual obligation by the customer.