Stainless steel as know as 1.4410 stainless steel, is a widely used material known for its excellent corrosion resistance and strength, playing an important role in various industries. Among the many types of stainless steel, 316 stainless steel stands out due to its superior performance, especially its corrosion resistance in extreme environments.
This article will explore the composition, properties, advantages, and common applications of 316 stainless steel, providing a comprehensive understanding of its benefits and suitable use cases.
What is 316 Stainless Steel
316 stainless steel is an austenitic stainless steel containing 18% chromium (Cr), 8% nickel (Ni), and 2% molybdenum (Mo). It improves upon 304 stainless steel by adding molybdenum, which significantly enhances its resistance to corrosion, especially against chlorides and acid-base solutions. This makes 316 stainless steel popular in marine, chemical, and food processing industries. Its corrosion resistance and mechanical strength are superior to 304 stainless steel, making it particularly effective in harsh environments.
316 Stainless Steel Chemical Composition
The main feature of 316 stainless steel is the addition of molybdenum, which significantly improves its resistance to corrosion in chloride and acid-base environments. This allows 316 stainless steel to maintain stability in highly corrosive environments such as seawater, salt fog, and chemical solutions.
Compared to 304 stainless steel, which also has good corrosion resistance, 316 performs much better in chloride environments.
In addition to molybdenum, 316 stainless steel has higher chromium and nickel contents, which provide excellent oxidation resistance and high-temperature strength. Below is the typical chemical composition of 316 stainless steel:
Element | Content Range (%) |
Chromium (Cr) | 16.0 – 18.0 |
Nickel (Ni) | 10.0 – 14.0 |
Molybdenum (Mo) | 2.0 – 3.0 |
Carbon (C) | ≤ 0.08 |
Manganese (Mn) | ≤ 2.0 |
Silicon (Si) | ≤ 1.0 |
Phosphorus (P) | ≤ 0.045 |
Sulfur (S) | ≤ 0.03 |
Nitrogen (N) | ≤ 0.10 |
316 Stainless Steel Equivalents
316 stainless steel has different designations across various countries and standards. While the chemical composition of 316 stainless steel is generally consistent worldwide, different countries may use different identifiers. Below are the common designations for 316 stainless steel in major standards:
| Country/Standard | Model | Description |
| USA (ASTM) | ASTM A240 Type 316 | Standard for stainless steel sheet and strip. |
| ASTM A276 316 | Standard for stainless steel bars. | |
| ASTM A312 316 | Standard for stainless steel pipes. | |
| ASTM A484 316 | Standard for stainless steel forgings and castings. | |
| Europe (EN) | EN 1.4401 | Standard designation widely used for most 316 stainless steel applications. |
| EN 1.4404 | Low-carbon version, suitable for welding to reduce carbide precipitation and improve corrosion resistance. | |
| EN 1.4435 | Ultra-low carbon version, suitable for extremely demanding corrosion-resistant applications. | |
| Japan (JIS) | JIS G4303 SUS316 | Japanese standard for stainless steel sheet and bars. |
| JIS G3446 SUS316 | Japanese standard for stainless steel pipes. | |
| Germany (DIN) | DIN 17440 X5CrNiMo17-12-2 | German DIN standard for 316 stainless steel. |
| DIN 17175 16Mo3 | Suitable for high-temperature and high-pressure environments. | |
| UK (BS) | BS 1449 316S31 | British standard for 316 stainless steel. |
| BS 3146 316S11 | High-strength and corrosion-resistant version of 316 stainless steel. | |
| China (GB) | GB/T 4237-2008 0Cr17Ni12Mo2 | Chinese GB standard for 316 stainless steel. |
| International (ISO) | ISO 3506-1 A4-70 | Standard for 316 stainless steel used in fasteners. |
| ISO 15510 | ISO standard for stainless steel alloy compositions. |
316 Stainless Steel Physical Properties
The physical properties of 316 stainless steel make it particularly useful in applications requiring resistance to extreme environments. Key physical properties include:
- Density: 316 stainless steel has a density of approximately 7.98 g/cm³, slightly higher than 304 stainless steel (7.93 g/cm³) due to the addition of molybdenum.
- Thermal Conductivity and Electrical Conductivity: The thermal conductivity is 16.3 W/m·K, and the electrical conductivity is 1.3 × 10⁶ S/m. While these values are lower than metals like aluminum and copper, they are sufficient for most industrial applications.
- Melting Point: 316 stainless steel has a melting point of 1371-1399°C, which is lower than 304 stainless steel but still suitable for most high-temperature applications.
- Thermal Expansion Coefficient: 316 stainless steel has a thermal expansion coefficient of 16.5 × 10⁻⁶ /°C, slightly lower than 304 stainless steel, meaning it expands less with temperature changes.
- Magnetism: 316 stainless steel is non-magnetic at room temperature, making it ideal for environments where magnetism is undesirable.
These physical properties make 316 stainless steel ideal for applications with significant temperature changes or high-temperature requirements.
316 Stainless Steel Mechanical Properties
316 stainless steel excels not only in corrosion resistance but also in its mechanical properties. Its main mechanical properties include:
- Tensile Strength: 316 stainless steel has a tensile strength of 515-725 MPa, slightly higher than 304 stainless steel, making it suitable for high-stress applications.
- Yield Strength: The yield strength is 205 MPa, similar to that of 304 stainless steel, making it ideal for most general-purpose applications.
- Ductility: 316 stainless steel has a high elongation rate of more than 40%, allowing it to be easily formed into complex shapes without losing flexibility.
- Fatigue Strength: The fatigue strength is about 230 MPa, meaning it can withstand repeated loading over time.
- Impact Toughness: 316 stainless steel has high impact toughness, making it resistant to sudden impacts and avoiding brittle fractures.
These mechanical properties make 316 stainless steel highly suitable for pressure vessels, aerospace, and applications requiring long-term stability and fatigue resistance.
316 Stainless Steel Corrosion Resistance
One of the most significant advantages of 316 stainless steel is its excellent corrosion resistance. The addition of molybdenum makes it highly resistant to corrosion in aggressive environments:
- Chloride Environments: 316 stainless steel performs excellently in chloride environments, making it ideal for use in seawater, salt fog, and similar corrosive conditions.
- Acidic Environments: It also shows good resistance to sulfuric acid, phosphoric acid, and other acidic substances, making it suitable for chemical processing equipment.
- Alkaline Environments: 316 stainless steel also resists corrosion in alkaline solutions, making it ideal for chemical vessels and containers.
As a result, 316 stainless steel is widely used in marine engineering, chemical industries, food processing, and other highly corrosive environments.
316 Stainless Steel Welding and Machining
316 stainless steel offers good welding and machining properties. However, the presence of molybdenum can pose some challenges during welding, so post-welding treatments, such as passivation, are often required to prevent corrosion in the welded area. Due to its good ductility, 316 stainless steel also performs well in most machining processes, including stamping, deep drawing, and bending.
316 Stainless Steel Processing Methods
316 stainless steel can be processed using various methods, including casting, machining, and surface treatments. Common processing methods include:
Investment casting, also known as precision casting, is suitable for producing complex-shaped parts with high precision.
Process: A wax model is coated with a ceramic slurry, and then the wax is melted out, leaving a mold for pouring liquid 316 stainless steel.
Applications: Aerospace parts, pump bodies, valves, chemical equipment, medical devices.
2.Sand Casting
Sand casting is the most common casting process, suitable for large, simple parts.
Process: Liquid 316 stainless steel is poured into a sand mold, then cooled and removed to create the casting.
Applications: Heavy machinery parts, marine equipment casings, construction components.
316 stainless steel can be machined using traditional methods such as turning, milling, drilling, and grinding.
Applications: Precision parts, fasteners, industrial components.
4.Welding
316 stainless steel can be welded using methods such as TIG (Tungsten Inert Gas) welding, MIG (Metal Inert Gas) welding, and laser welding.
Applications: Large structures, pipelines, tanks, chemical containers.
5.Stamping
316 stainless steel can be stamped into various shapes and forms through the application of high-pressure tools.
Applications: Automotive parts, appliance parts, decorative items.
316 Stainless Steel Applications
316 stainless steel is used across a wide range of industries due to its excellent corrosion resistance, strength, and versatility. Common applications include:
Marine Industry: Due to its resistance to saltwater corrosion, it is commonly used in boat fittings, marine hardware, and offshore platforms.
Chemical Processing: It is used for tanks, piping, and reactors in chemical processing plants due to its resistance to acidic and alkaline substances.
Food and Beverage Industry: It is used for food processing equipment and medical devices because it does not react with food and beverages, maintaining hygiene and quality.
Aerospace: 316 stainless steel is used in components exposed to high temperatures and pressure, such as aircraft exhaust systems and turbine blades.
Medical Devices: Its non-reactive properties make it ideal for surgical instruments, implants, and prosthetics.
Construction: Stainless steel is used in architecture and construction for decorative elements, structural supports, and reinforced materials.
316 Stainless Steel Advantages
316 stainless steel can be processed using various methods, including casting, machining, and surface treatments. Common processing methods include:
Superior Corrosion Resistance: Ideal for environments where other stainless steels, such as 304, would fail, especially in the presence of chlorides and other corrosive chemicals.
High Strength: Provides excellent tensile strength, which is critical in heavy-duty applications.
Durability: The material can endure harsh conditions, extreme temperatures, and wear, ensuring longevity of equipment.
Hygienic Properties: Because it does not react with food, beverages, or human tissue, 316 stainless steel is highly valued in food and medical industries.
Aesthetic Appeal: Its clean, shiny finish makes it attractive for decorative and architectural purposes.
How Can Manek Help
At Manek, we offer our clients a series of customized services specifically for stainless steel and other metals, including investment casting, sand casting, die casting, CNC machining, sheet metal fabrication as well as various surface treatments.
We also provide a variety of other manufacturing capabilities. You can get quotations for free, such as 3D printing, plastic injection molding and powder coating.
316 stainless steel’s combination of excellent corrosion resistance, strength, and versatility makes it one of the most reliable materials for a wide range of industrial and commercial applications. Whether used in marine environments, chemical processing, or medical devices, 316 stainless steel provides long-term durability and performance in extreme conditions.
