What is SUS Material?

The SUS material standard refers to the classification of stainless steel grades according to the Japanese Industrial Standard (JIS). The term SUS stands for Stainless Steel Use Steel, with a numerical code following it that defines the specific alloy’s composition and characteristics. For example, SUS 304 represents an austenitic stainless steel commonly used in various industries for its excellent corrosion resistance. The SUS standard covers several grades of stainless steel, each with unique properties like corrosion resistance, tensile strength, and formability.

The terms SUS and SS are often used interchangeably but have subtle differences:

• SUS: This term is used primarily in Japan and refers to stainless steel grades classified under the Japanese Industrial Standard (JIS). The “SUS” designation is followed by a number indicating the grade of stainless steel, such as SUS 304, SUS 316, etc.
• SS: This term is more widely used globally and stands for Stainless Steel, representing a broad category of steel alloys that contain a minimum of 10.5% chromium by mass, which provides their characteristic corrosion resistance. SS is commonly followed by numbers like 304, 316, or 430, but these can be based on various international standards like ASTM (American Society for Testing and Materials) or AISI (American Iron and Steel Institute).

In summary, SUS refers specifically to the JIS standard, while SS is a general term for stainless steel that can be found in various international systems.

In the context of metal, SUS is an abbreviation for Stainless Steel Use Steel under the Japanese Industrial Standard (JIS). It is a prefix used for various grades of stainless steel alloys, indicating that the material meets specific standards for stainless steel’s strength, corrosion resistance, and other properties. SUS steels are primarily used in industries where these properties are crucial, such as food processing, medical equipment, and construction.

Both SUS 304 and SUS 316 are popular grades of stainless steel, but they differ in several key aspects:

• SUS 304 (18-8 stainless steel): It contains approximately 18% chromium and 8% nickel, offering excellent corrosion resistance, particularly in environments that are not exposed to high levels of chlorides (e.g., in indoor and mild outdoor applications).
• SUS 316: This grade contains 16-18% chromium, 10-14% nickel, and 2-3% molybdenum, which enhances its resistance to corrosion, especially in chloride-rich environments like coastal or marine areas. SUS 316 is highly resistant to pitting and crevice corrosion, making it ideal for chemical and marine applications.

Which is better? If you’re working in a more aggressive environment with exposure to saltwater or chemicals, SUS 316 is the better choice due to its superior corrosion resistance. However, SUS 304 is often sufficient for less demanding applications and is typically more cost-effective.

The SUS standard is a classification system for stainless steel materials under the Japanese Industrial Standard (JIS). It designates stainless steel grades with the prefix “SUS” followed by a numeric code, such as SUS 304, SUS 316, etc. This system ensures that the materials meet specific mechanical properties, chemical compositions, and performance requirements for various industrial applications. The SUS standard is widely recognized in Japan and is used as a reference for stainless steel grades worldwide.

The primary difference between SUS 316 and AISI 316 lies in their respective standards:

• SUS 316: This is a stainless steel grade designated under the Japanese Industrial Standard (JIS) system. It is the Japanese equivalent of AISI 316 and adheres to the same chemical composition and mechanical properties.
• AISI 316: The American Iron and Steel Institute (AISI) designation refers to a similar grade of stainless steel but is part of the AISI/ASTM standard system, which is commonly used in North America. It shares the same basic composition as SUS 316 and offers the same high resistance to corrosion, especially in chloride environments.

In essence, SUS 316 and AISI 316 represent the same stainless steel grade but are based on different regional standards. The material properties are identical, but the naming conventions differ according to the standards used in Japan (JIS) and the United States (AISI).