What is SUS304 and SS 304 ?

December 8, 2023

SUS304 and SS304 both refer to the same stainless steel grade, known as austenitic stainless steel. SUS304 is the Japanese designation according to JIS (Japanese Industrial Standards), while SS304 is the American designation based on AISI (American Iron and Steel Institute) standards. Despite the nomenclature difference, there is no significant distinction between the two grades.

Mechanical properties are often cited as a potential differentiator, but samples of stainless steel SUS304 from a Japanese source and stainless steel 304 from an American source were collected for testing in a mechanical lab, revealing no noteworthy differences.

SUS304 is a widely used stainless steel in Japan, characterized by its composition of 18% chromium (Cr) and 8% nickel (Ni). This alloy exhibits excellent strength, heat resistance in both high and low-temperature environments, corrosion resistance, weldability, cold workability, and overall favorable mechanical properties at room temperature.

AISI 304 stainless steel, commonly referred to as SS304, is the predominant material in stainless steel applications. It is typically purchased in an annealed or cold-condition state. SS304, also known as 18/8 due to its 18% chromium and 8% nickel content, boasts exceptional processability, weldability, corrosion resistance, heat resistance, low-temperature strength, and versatile mechanical characteristics. It finds widespread use in industrial applications, furniture decoration, the food industry, medical applications, and more.