Understanding SUS 304 Meaning: Composition, Properties, and Industrial Applications
Stainless steel is one of the most versatile materials used across industries—from kitchenware and medical tools to automotive components and construction structures. Among the many stainless steel grades available, SUS 304 stands out as one of the most widely used and trusted. But what exactly is the SUS 304 meaning, and why is it so important in modern manufacturing?
In this article, we’ll dive into the origins, composition, and properties of SUS 304 stainless steel. We’ll also explain how it compares to SS304, explore its real-world applications, and show why manufacturers like CSMFG rely on it for precision fabrication and global sourcing projects.
What Does SUS 304 Mean?
To understand SUS 304 meaning, it’s important to look at how stainless steel is classified globally. The prefix “SUS” comes from the Japanese Industrial Standards (JIS) and stands for Steel Use Stainless. It designates grades of stainless steel defined under the JIS system, which is widely used in Japan and throughout Asia.
The number “304” indicates the material grade, which corresponds closely to AISI 304 under the American standard. Therefore, when you see SUS 304, you’re essentially looking at the Japanese equivalent of SS304 stainless steel. The difference lies mainly in naming conventions and sometimes in minor tolerances or test standards.
In practical terms, SUS 304 meaning refers to a non-magnetic, austenitic stainless steel that offers excellent corrosion resistance, formability, and strength. These qualities make it one of the most common materials used for stainless steel products worldwide.
Chemical Composition and Mechanical Properties
The strength and durability of SUS 304 come from its balanced chemical composition. It typically contains:
- Chromium (18–20%) – improves oxidation and corrosion resistance
- Nickel (8–10.5%) – enhances toughness and ductility
- Carbon (≤0.08%) – limits carbide precipitation for better weldability
- Manganese, Silicon, and Iron – provide stability and mechanical strength
This precise formulation gives SUS 304 its characteristic combination of strength and malleability. It can be easily rolled, stamped, or deep-drawn into complex shapes without cracking.
Mechanically, SUS 304 exhibits:
- Tensile Strength: 515 MPa or higher
- Yield Strength: around 205 MPa
- Elongation: approximately 40%
- Hardness: ≤ 90 HRB
These values make it suitable for both structural and decorative applications. In addition, SUS 304 meaning encompasses its non-magnetic behavior in the annealed state, though slight magnetism may occur after cold working.
Because of its excellent weldability and machinability, it’s favored in custom part manufacturing—a key area where CSMFG excels. Their expertise in precision metal fabrication allows clients to take full advantage of SUS 304’s formability and strength in tailored designs.
SUS 304 vs SS304: Are They the Same?
A common question engineers ask is whether SUS 304 and SS304 are the same material. The short answer: yes, they are essentially equivalent.
- SUS 304 is defined under JIS (Japanese Industrial Standards).
- SS304 falls under AISI/ASTM (American standards).
Both share nearly identical chemical compositions and performance properties. The difference mainly lies in naming conventions and certification processes. For instance, a product labeled SUS 304 may be produced according to Japanese specifications, while SS304 follows American guidelines.
From a practical standpoint, these materials perform identically in most environments. Therefore, when sourcing globally, understanding SUS 304 meaning helps you ensure you’re getting the right stainless steel equivalent, no matter which system your supplier uses.
CSMFG, with its extensive experience in international sourcing and manufacturing, ensures full compliance with multiple global standards—JIS, ASTM, DIN, and ISO. This makes them a trusted partner for customers looking for quality stainless steel components, whether labeled SUS 304 or SS304.
Applications of SUS 304 Stainless Steel
Because of its versatility and durability, SUS 304 is used in an extraordinary range of applications. Here are some of the most common:
1. Food and Kitchen Equipment
SUS 304 is used in cookware, cutlery, kitchen sinks, and food processing machines because it resists rust and corrosion even when exposed to water and acids. Its smooth surface also makes it easy to clean and maintain hygiene standards.
2. Medical Instruments
The biocompatibility and non-reactive nature of SUS 304 make it suitable for surgical tools, hospital equipment, and laboratory containers. It can be sterilized repeatedly without losing its mechanical integrity.
3. Automotive and Transportation
In the automotive industry, SUS 304 is found in exhaust systems, trim parts, and fuel tanks due to its resistance to oxidation at high temperatures. It also provides a polished appearance for decorative elements.
4. Industrial and Structural Use
SUS 304 is widely used for tanks, piping, fasteners, and pressure vessels. Its combination of tensile strength and corrosion resistance makes it ideal for chemical plants, water treatment systems, and refineries.
In each of these examples, understanding SUS 304 meaning allows engineers to choose the right grade for durability, appearance, and cost-effectiveness.
If your business needs reliable stainless steel parts, CSMFG provides professional manufacturing and supply chain solutions using SUS 304 stainless steel to meet international quality standards.
Comparison with Other Stainless Steels
While SUS 304 is one of the most popular grades, it’s often compared with others like SUS 316, SUS 430, and SUS 201.
- SUS 316: Contains molybdenum, offering better resistance to chloride corrosion, making it suitable for marine environments.
- SUS 430: A ferritic grade with less nickel, providing moderate corrosion resistance at a lower cost.
- SUS 201: A cost-effective alternative with higher manganese and lower nickel, but slightly less corrosion resistance.
Choosing between these depends on your environmental exposure, budget, and functional needs. For most indoor and general applications, SUS 304 remains the ideal choice thanks to its balanced performance.
Why Manufacturers Prefer SUS 304
There are several reasons why manufacturers around the world—especially precision engineers—prefer SUS 304:
- Excellent Fabrication Ability – It can be welded, machined, and formed into complex geometries with minimal risk of cracking.
- Superior Surface Finish – SUS 304 achieves a bright, polished appearance, ideal for decorative or visible parts.
- Corrosion Resistance – Its chromium-nickel blend protects against rust, oxidation, and many chemicals.
- Economical Choice – Compared with high-alloy steels like SUS 316, it delivers outstanding performance at a reasonable price.
- Sustainability – SUS 304 is 100% recyclable, aligning with modern environmental standards.
At CSMFG, engineers recommend SUS 304 for clients who need components that balance performance, durability, and cost efficiency. Whether you need sheet metal parts, custom brackets, or machined fittings, their manufacturing expertise ensures each part meets your exact specifications.
How to Identify Genuine SUS 304
Since stainless steel grades can look similar, verifying SUS 304 meaning also means ensuring you’re getting authentic material. Here’s how:
- Check certifications such as JIS G4303 or ASTM A240.
- Perform magnet tests (SUS 304 is mostly non-magnetic).
- Review supplier documentation and mill test reports.
- Partner with verified manufacturers like CSMFG, who provide full traceability and quality assurance for every stainless steel batch.
Conclusion
Understanding SUS 304 meaning goes beyond its name—it’s about recognizing the balance of strength, corrosion resistance, and affordability that defines modern stainless steel manufacturing. As an austenitic stainless steel grade, SUS 304 continues to serve as the industry standard for versatility and performance across numerous applications.
Whether you’re designing kitchen appliances, medical instruments, or industrial systems, choosing the right stainless steel can determine your product’s reliability and lifespan.
If you’re looking for a trusted partner to supply or manufacture components made from SUS 304 or equivalent stainless steel grades, visit CSMFG. With extensive experience in custom fabrication, material sourcing, and quality control, CSMFG helps businesses worldwide achieve precise, cost-effective results with premium stainless steel materials.