Stainless Steel 321 Flanges | ASC LLP
Stainless steel is a cornerstone material in numerous industrial applications due to its exceptional strength, corrosion resistance, and versatility. Among the various grades of stainless steel, 321 stainless steel stands out, particularly for its use in manufacturing flanges. At ASC LLP, we pride ourselves on offering high-quality stainless steel 321 flanges that meet the stringent demands of our global clientele.
What is 321 Stainless Steel Flanges?
321 stainless steel flanges are essential components used to connect pipes, valves, pumps, and other equipment within a piping system. These flanges are manufactured from 321-grade stainless steel, ensuring they inherit the material’s unique properties, such as enhanced corrosion resistance, high-temperature strength, and durability. The flanges are designed to withstand extreme environmental conditions, making them ideal for use in industries such as petrochemicals, power generation, and aerospace.

Properties of 321 Stainless Steel Flanges
When selecting flanges for critical applications, understanding the properties of the material is essential. The key properties of 321 stainless steel flanges include:
- Corrosion Resistance: 321 stainless steel offers excellent resistance to corrosion, particularly in environments that involve oxidizing agents, high temperatures, and intergranular corrosion. The titanium addition effectively reduces the risk of carbide precipitation at high temperatures, making these flanges ideal for service in the 500°C to 800°C range.
- Heat Resistance: One of the standout features of 321 stainless steel flanges is their superior heat resistance. They maintain their mechanical strength and corrosion resistance in high-temperature environments, making them suitable for applications such as heat exchangers, boiler components, and exhaust systems.
- Weldability: 321 SS flanges exhibit excellent weldability, reducing the risk of cracking and other issues during the welding process. The titanium content helps prevent the formation of chromium carbides, which can cause localized corrosion near the welds.
- Durability: These flanges are known for their robustness and durability. They can withstand harsh environmental conditions, including exposure to chemicals, acids, and elevated temperatures, without compromising their structural integrity.
- Non-Magnetic: Like most austenitic stainless steels, 321 SS flanges are non-magnetic, making them suitable for applications where magnetic interference must be avoided.
- Good Formability and Machinability: 321 stainless steel can be easily formed into various shapes, making it an excellent choice for custom flange designs. Additionally, it can be machined with standard techniques, ensuring high precision in manufacturing.
Advantages of 321 Stainless Steel Flanges
321 stainless steel flanges offer several advantages over other types of stainless steel flanges:
- Enhanced Corrosion Resistance: The addition of titanium in 321 stainless steel improves its resistance to corrosion, particularly in environments where other grades might fail. This makes 321 SS flanges a reliable choice for applications involving exposure to acidic or oxidizing environments.
- Long Service Life: The durability and resistance to high temperatures and corrosion ensure that 321 stainless steel flanges have a long service life, reducing the need for frequent replacements and minimizing downtime in critical operations.
- Versatility in Application: SS 321 flanges can be used in a wide range of applications, from piping systems in chemical plants to exhaust manifolds in high-performance engines. Their ability to perform well in both cryogenic and high-temperature environments makes them highly versatile.
- Cost-Effective: Despite their superior properties, 321 stainless steel flanges are relatively cost-effective compared to other high-performance alloys. Their long service life and low maintenance requirements further contribute to cost savings in industrial operations.
- Stability in High-Temperature Environments: Unlike other stainless steels that may become brittle or suffer from carbide precipitation at high temperatures, 321 stainless steel flanges maintain their strength and corrosion resistance, ensuring stable performance even in demanding conditions.


Schedule and Size Chart
Nominal Pipe Size (NPS) | Outside Diameter (OD) | Schedule 10S | Schedule 40S | Schedule 80S |
1/2″ | 21.34 mm | 2.11 mm | 2.77 mm | 3.73 mm |
3/4″ | 26.67 mm | 2.11 mm | 2.87 mm | 3.91 mm |
1″ | 33.40 mm | 2.77 mm | 3.38 mm | 4.55 mm |
1 1/2″ | 48.26 mm | 2.77 mm | 3.68 mm | 5.08 mm |
2″ | 60.33 mm | 2.77 mm | 3.91 mm | 5.54 mm |
3″ | 88.90 mm | 3.05 mm | 5.49 mm | 7.62 mm |
4″ | 114.30 mm | 3.05 mm | 6.02 mm | 8.56 mm |
6″ | 168.28 mm | 3.40 mm | 7.11 mm | 10.97 mm |
8″ | 219.08 mm | 3.76 mm | 8.18 mm | 12.70 mm |
Mechanical Properties Chart
Property | Value |
Tensile Strength | 515 MPa (74,700 psi) |
Yield Strength | 205 MPa (29,700 psi) |
Elongation at Break | 40% |
Hardness (Brinell) | 217 HB max |
Modulus of Elasticity | 193 GPa (28,000 ksi) |
Poisson’s Ratio | 0.27 – 0.30 |
Impact Toughness | 75 J (55 ft-lbf) |
Specifications Chart
Standard | Specification |
ASTM | A182, A240, A312, A403, A479, A813, A814 |
ASME | SA182, SA240, SA312, SA403, SA479, SA813, SA814 |
EN | 1.4541 |
DIN | 1.4541 |
JIS | SUS 321 |
UNS | S32100 |
Chemical Composition Chart
Element | Composition (%) |
Carbon (C) | ≤ 0.08 |
Manganese (Mn) | ≤ 2.00 |
Phosphorus (P) | ≤ 0.045 |
Sulfur (S) | ≤ 0.030 |
Silicon (Si) | ≤ 0.75 |
Chromium (Cr) | 17.0 – 19.0 |
Nickel (Ni) | 9.0 – 12.0 |
Titanium (Ti) | ≥ 5 x C% (but ≤ 0.7%) |
Iron (Fe) | Balance |
Physical Properties Chart
Property | Value |
Density | 7.9 g/cm³ |
Melting Point | 1,400 – 1,425 °C (2,552 – 2,597 °F) |
Thermal Conductivity | 16.3 W/m·K at 100°C |
Specific Heat Capacity | 500 J/kg·K at 25°C |
Electrical Resistivity | 0.072 Ω·mm²/m at 20°C |
Thermal Expansion | 16.5 µm/m·K (20°C to 1000°C) |
Application Chart
Industry | Applications |
Aerospace | Exhaust systems, heat exchangers, high-temperature components |
Chemical Processing | Processing equipment, piping systems handling corrosive fluids |
Power Generation | Boilers, superheaters, heat exchangers, turbine parts |
Petrochemical | Oil and gas refining equipment, pipelines, flanges |
Automotive | Exhaust manifolds, catalytic converters |
Food Processing | Food handling equipment, high-temperature applications |
Pharmaceutical | Sterilization and processing equipment |
Pulp and Paper | Digesters, bleaching equipment |
Why Choose ASC LLP for 321 Grade Stainless Steel Flanges?
At ASC LLP, we pride ourselves on delivering the highest quality 321 grade stainless steel flanges to our customers. Here’s why you should choose us:
- Expertise: With decades of experience in the steel industry, we understand the specific needs of our clients and deliver products that exceed their expectations.
- Quality Assurance: Our 321 SS flanges undergo rigorous testing and quality checks to ensure they meet the highest industry standards.
- Customization: We offer a wide range of sizes, dimensions, and specifications to meet the unique requirements of your project.
- Global Reach: Serving clients across the globe, we are committed to providing prompt delivery and exceptional customer service, no matter where you are located.
321 stainless steel flanges are an excellent choice for applications requiring high resistance to heat and corrosion. With their exceptional properties and advantages, these flanges are essential components in industries such as aerospace, chemical processing, and power generation. When you choose 321-grade SS flanges from ASC LLP, you can be confident that you are getting a product that is built to last and perform under the most demanding conditions.
Global Reach
Amardeep Steel Centre boasts a robust global presence, committed to delivering unparalleled service and quality to clients around the world. Our dedication to prompt delivery and exceptional customer care sets us apart in the industry. Major corporations across the USA, Europe, Asia, and other regions place their trust in our high-quality Stainless Steel 321 Flanges. This widespread trust underscores our reputation for reliability and excellence. By consistently meeting and exceeding the expectations of our international clientele, we continue to solidify our position as a leader in the global steel market.

Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.