Stainless steel is a versatile metal that is closely linked to our daily lives and work. It is commonly used for tableware, architectural decoration, and even sculpture. One notable example is The Bean (Cloud Gate) in Chicago, which is entirely made of stainless steel. Advanced computer technology was used to accurately cut 168 large steel plates, which were then spliced and welded together to create a seamless effect. However, its primary importance lies in its use as an industrial product.
Understanding the stainless steel characteristics and applications will help you with your purchase. Stainless steel is a major product of SSM. Our range includes stainless steel pipes, pipe fittings, flanges, fasteners, plates, and bars. Let’s delve deeper into the world of stainless steel with us.
Cloud Gate, aka “The Bean”, is one of Chicago’s most popular sights.
What is stainless steel?
Stainless steel is a corrosion-resistant alloy. Its main components are iron, chromium (usually at least 10.5%), nickel, and a small amount of carbon. Chromium is the crucial element that provides corrosion resistance to stainless steel. When the chromium content reaches 10.5% or more (which is when we call it stainless steel), a protective chromium oxide film forms on the steel surface. This passivation film effectively prevents further oxidation and corrosion.
Stainless Steel Characteristics
Stainless steel is a remarkable material with numerous key attributes:
1. Unmatched corrosion resistance: It can withstand corrosion in diverse environments, including moisture, acid, alkali, and salt water, making it an ideal choice for construction, medical equipment, chemical equipment, and household appliances.
2. Superior strength and toughness: Its enduring strength and toughness across a wide temperature range make it perfect for structural applications and high-temperature environments.
3. Aesthetic and easy to maintain: With its smooth surface, striking gloss, and easy cleanability, stainless steel is a lasting choice for kitchen utensils and architectural decoration.
4. Remarkable versatility: Altering the alloy composition and manufacturing process enables stainless steel to achieve a range of properties, including enhanced strength, wear resistance, and weldability.
Stainless Steel Classifications
Here is the translated table in English, comparing the differences between Austenitic, Ferritic, Martensitic, Duplex, and Precipitation Hardening stainless steels, including common grades:
| Category | Crystal Structure | Main Composition | Typical Properties | Common Grades | Applications |
| Austenitic Stainless Steel | Face-Centered Cubic (FCC) | Chromium (16-26%), Nickel (6-22%) | Excellent corrosion resistance, good formability and weldability, non-magnetic, good high-temperature strength. | 304, 316, 321, 304L | Chemical equipment, food processing equipment, kitchen utensils, medical instruments, etc. |
| Ferritic Stainless Steel | Body-Centered Cubic (BCC) | Chromium (10.5-30%), Low Carbon Content | Good corrosion and oxidation resistance, lower cost, magnetic, poor weldability. | 430, 409, 439 | Automotive exhaust systems, decorative materials, industrial containers, household utensils. |
| Martensitic Stainless Steel | Body-Centered Cubic (BCC) | Chromium (12-18%), Higher Carbon Content | High strength, high hardness, good wear resistance, lower corrosion resistance, properties can be adjusted by heat treatment. | 410, 420, 440C | Knives, tools, bearings, surgical instruments, etc. |
| Duplex Stainless Steel | Austenitic + Ferritic Mixed | Chromium (22-25%), Nickel (4.5-7%) | Combines the advantages of austenitic and ferritic, high strength, excellent resistance to stress corrosion, good weldability. | 2205, 2507 | Oil and gas industry, chemical transport, marine structures, shipbuilding, etc. |
| Precipitation Hardening Stainless Steel | Austenitic or Martensitic Matrix | Chromium (15-17%), Nickel (3-5%), Molybdenum, etc. | Strength and hardness are increased through heat treatment (aging treatment), combines high strength and corrosion resistance. | 17-4PH, 15-5PH, 13-8Mo | Aerospace components, high-performance tools, springs, turbine blades, etc. |
Stainless Steel Grade System
The stainless steel grade system is a standardized way of classifying and identifying stainless steel alloys, based on their chemical composition, microstructure, physical properties, and applications. There are several common stainless steel grade systems, including:
American Iron and Steel Institute (AISI) system: This is the most commonly used system, using three or four digits to indicate the type of stainless steel.
– Austenitic stainless steel: starts with 3XX, such as 304, 316.
– Ferritic stainless steel: starts with 4XX, such as 430, 409.
– Martensitic stainless steel: starts with 4XX, such as 410, 420.
In addition to the AISI system, there is the United Numbering System (UNS), European standards (EN), Japanese Industrial Standards (JIS), and Chinese National Standards (GB) system. Each system is designed to ensure consistency and traceability of stainless steel materials, helping engineers and manufacturers identify and select the right materials worldwide.
This table outlines how 304 stainless steel is identified and standardized across different international systems, ensuring consistency in material specifications globally.
| Standard | AISI | UNS | EN | JIS | GB |
| Description | 304 stainless steel | UNS S30400 | EN 1.4301 | SUS304 | GB 06Cr19Ni10 |
Among the 300 series stainless steel, the materials of SSM stainless steel products mainly include 304 and 316 stainless steel，read more about 304 vs 316 stainless steel.
For more information, see our page on stainless steel types.
Application of Stainless Steel
Stainless steel is extensively utilized in various industries and daily life due to its outstanding corrosion resistance, strength, toughness, and appealing appearance. Below are the primary application scenarios of stainless steel:
Architecture & Decoration
Stainless steel is used for building exterior structures and decorations. It has good weather resistance and long-lasting beauty. It can also be used for public artworks due to its high strength and corrosion resistance.
Grades: 304, 316/316L
Food & Beverage Processing
It is widely used for its hygiene and ease of cleaning in kitchen utensils and tableware. It is also used to manufacture food processing and beverage production equipment to ensure that the material does not react chemically with food.
Grades: 304/304L, 430
Medical Devices & Pharmaceuticals
Stainless steel is used to manufacture scalpels, forceps, operating tables, etc., due to its high corrosion resistance and sterility. Some stainless steels are used to manufacture orthopedic implants such as screws and bone plates.
Grades: 420, 440C
Chemical & Oil and Gas
Stainless steel is widely used in chemical reaction vessels, storage tanks, pipelines, etc., as it can withstand corrosive chemicals. Duplex stainless steel is commonly used in platforms and pipelines in marine environments due to its stress corrosion resistance.
Grades: 316L, 317L, 904L, 2205, 2507
Automobile & Transportation
Ferritic stainless steel is often used to manufacture automobile exhaust pipes and mufflers due to its high temperature and oxidation resistance. Stainless steel is also used as a structural material for train carriages and hulls to increase durability and reduce maintenance requirements.
Grades: 409, 439, 304, 316L
Energy & power
Stainless steel is used for structural parts and fasteners of solar and wind power equipment to ensure its long-term durability in harsh environments. It is also used in nuclear reactors and related equipment due to its resistance to high temperatures and radiation corrosion.
Grades: 316Ti, 347, 304, 316, 2205
Water Treatment & Environmental Engineering
Stainless steel is used in water supply pipes and sinks to prevent pollution. It is also used to manufacture various components of sewage treatment equipment due to its corrosion resistance.
Grades: 304, 316/316L, 2205
These applications demonstrate the importance of stainless steel in different fields. Its versatility makes it an indispensable material in modern industry and life.
Why SSM is Your Trusted Supplier of Stainless Steel Products
Selecting the right stainless steel products for your project is a critical decision, and at SSM, we understand that it shouldn’t be left to chance. We go beyond being just a supplier – we are your reliable partner in providing stainless steel products.
Get in touch with us today for a free quote and experience the difference of partnering with true experts in metal excellence.
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