SUS 304 VS SS304 stainless steel

SUS 304 and SS304 essentially refer to the same type of 304 stainless steel, with the difference being the naming system:
SUS 304 is the brand identification of Japanese Industrial Standards (JIS); SS304 (or 304) is a commonly used commercial grade according to the American ASTM/AISI standards.

The core components and performance of SUS 304 and SS304 stainless steel are completely consistent:
Both contain chromium (18-20%) and nickel (8-10.5%), and have the same corrosion resistance, processability, and application range (such as food equipment and building components), which can be regarded as the same material in different standard codes.