Grade Identification :
SS 321 and 321H; UNS S32100 and S32109, with titanium-stabilized metallurgy.
Grade Identification :
SS 321 and 321H; UNS S32100 and S32109, with titanium-stabilized metallurgy.
Material Standard :
ASTM A182 / ASME SA182 for forged stainless steel flanges.
Design Compliance :
ASME B16.5, B16.47, B16.48, EN 1092, DIN, BS and related international standards.
Size Availability :
1/2" (15 NB) to 48" (1200 NB) for project-specific flange configurations.
SS 321 flanges are precision-engineered components made from titanium-stabilized austenitic stainless steel, specifically developed to deliver superior corrosion resistance and high-temperature performance. These flanges are designed to ensure secure pipe connections in critical systems, offering long-term durability in corrosive and thermally active environments. SS 321 is ideal for continuous service temperatures up to 870°C, while SS 321H, with a higher carbon content, provides enhanced strength and creep resistance in high-pressure applications. Available in a wide range of types—including weld neck, slip-on, socket weld, blind, and threaded variants—these flanges conform to global standards like ANSI, ASTM, DIN, and JIS, ensuring compatibility across diverse industrial systems.
Technical Overview
The core advantage of SS 321/321H lies in their metallurgical stability under high thermal stress. The titanium content in both grades stabilizes the material against chromium carbide precipitation, which commonly occurs during welding or exposure to elevated temperatures. This property enhances the flanges’ resistance to intergranular corrosion—a critical factor in welded assemblies. Flanges SS 321H, characterized by its increased carbon content (0.04–0.10%), is specifically tailored for service where greater mechanical strength and prolonged exposure to elevated temperatures are involved.
Mechanically, these flanges offer a balanced combination of tensile strength, ductility, and oxidation resistance. Their fabrication compatibility with standard welding and machining methods allows for easy integration into custom pipeline systems. Both grades exhibit excellent dimensional stability under load, withstanding thermal cycling without degradation. This makes them suitable for pressure-rated systems and pipelines transporting aggressive fluids or gases.
Applications & Industry Use
321/321H flanges are widely deployed in industries where temperature extremes and corrosive media are routine. Key sectors include oil and gas, petrochemicals, thermal and nuclear power, chemical processing, pharmaceuticals, food and beverage, and aerospace. Their use is prominent in heat exchangers, high-temperature exhaust manifolds, furnace components, pressure vessels, and reactors. The thermal resistance and strength retention of these flanges make them essential in piping systems where failure is not an option.
Kvn Steels is the leading manufacturer and supplier of these flanges to major industrial regions, including India, the United Arab Emirates (UAE), the Kingdom of Saudi Arabia (KSA), Kuwait, Qatar, the Sultanate of Oman, Iran, and Iraq. Their proven performance in high-demand environments, particularly across the Middle East and South Asia, has made them a trusted choice for engineering firms, EPC contractors, and end-users seeking resilient, long-life piping solutions.
| STANDARD | UNS | WNR. | JIS | EN |
|---|---|---|---|---|
| SS 321 | S32100 | 1.4541 | SUS 321 | X6CrNiTi18-10 |
| SS 321H | S32109 | 1.4878 | SUS 321H | X12CrNiTi18-9 |
SS 321 Slip On FlangesSS 321/321H Slip On Flanges
ASME SA213 SS 304L /304H Seamless Tube, ASTM A213 SS 304 Seamless Tubing, DIN 1.4301 / 1.4307 Seamless Tubes, UNS S30403 / S30409 Seamless Tube SS 321 SORF Flanges, UNS S32100 / S32109 Slip On Flanges, DIN 1.4541 SORF Flanges, ASME SA 182 SS F321H Slip-on Raised Face Flanges
SS 321/321H Weld Neck Flanges
ASME SA182 SS 321H WNRF Flanges, ASTM A182 Steel 321 Weld Neck Flanges, DIN 1.4541 Weld Neck Flanges, UNS S32100 Weld Neck Raised Face Flanges
SS 321/321H Blind Flanges
Stainless Steel ASTM A182 F321 Blind Flanges, UNS S32100 / DIN 1.4541 Blind Flanges, ASME SA182 SS 321H BLRF Flanges, SS 321/321H Blind Raised Face Flanges Supplier
SS 321/321H Threaded Flanges
DIN 1.4541 Threaded Flanges, UNS S32100 Screwed Flanges, ASME SA 182 SS 321H Threaded Flanges, ASTM A182 321/321H SS Threaded Flanges
SS 321/321H Socket Weld Flanges
ASTM A182 F321H SS Socket Weld Flanges, SS UNS S32100/ S32109 Socket Weld Flanges, SS DIN 1.4878 Socket Weld Flanges
SS 321/321H Lap Joint Flanges
UNS S32100 Lap Joint Flanges, SS 321 Lap Joint Flanges, ASTM A182 F321H Stainless Steel Lap Joint Flanges, ASME SA 182 SS 321/321H Lap Joint Flanges
SS 321/321H Ring Type Joint Flange
Stainless Steel 321/321H Orifice FlangesSS 321/321H Orifice Flanges
SS 321/321H Long Weld Neck Flanges
UNS S32109 Long Weld Neck Flanges, SS 1.4878 Long Weld Neck Flanges, ASTM A182 F321H Stainless Steel Long Weld Neck Flanges, ASME SA 182 SS 321/321H Long Weld Neck Flanges
SS 321/321H Spectacle Blind Flanges
ASTM A182 F321H Stainless Steel Socket Weld Flanges, SS UNS S32100/ S32109 Socket Weld Flanges, SS DIN 1.4878 Socket Weld Flanges
SS 321/321H Forged Flanges
UNS S32109 Forged Flanges, B16.5 Steel 321 Forged Flanges, ASTM A182 F321H Stainless Steel Forged Flanges, ASME SA 182 SS 321/321H Forged Flanges
SS 321/321H Ring Type Joint Flange
Stainless Steel 321/321H Orifice Flanges SS 321/321H Orifice Flanges
Stainless Steel 321/321H Plate Flanges SS 321/321H Plate Flanges
UNS S32100 Plate Flanges, ANSI B16.5 Stainless Steel 321 Plate Flanges, ASTM A182 F321H Stainless Steel Plate Flanges, ASME SA 182 SS 321/321H Plate Flanges
Grade Identification :
SS 321 and 321H; UNS S32100 and S32109, with titanium-stabilized metallurgy.
Material Standard :
ASTM A182 / ASME SA182 for forged stainless steel flanges.
Design Compliance :
ASME B16.5, B16.47, B16.48, EN 1092, DIN, BS and related international standards.
Size Availability :
1/2" (15 NB) to 48" (1200 NB) for project-specific flange configurations.
Pressure Rating :
150# to 2500# plus PN6, PN10, PN16, PN25, PN40 and PN64 options.
Face Configuration :
FF, RF and RTJ faces for different gasket and piping requirements.
Flange Types :
Slip-On, Weld Neck, Blind, Threaded, Socket Weld, Lap Joint, RTJ, Orifice and Long Weld Neck.
Service Advantage :
Titanium stabilization supports resistance to intergranular corrosion and maintains performance during elevated-temperature service.
Chemical Composition of SS 321/321H Flanges
| % | Cr | Ni | C | Si | Mn | P | S | N | Ti | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| 321 | min:17.0 max:19.0 |
min: 9.0 max:12.0 |
max:0.08 | max:0.75 | max:2.0 | max:0.045 | max:0.03 | max:0.10 | min:5*(C+N) max:0.70 |
Balance |
| 321H | min:17.0 max:19.0 |
min: 9.0 max:12.0 |
min:0.04 max:0.10 |
min:18.0 max:20.0 |
max:2.0 | max:0.045 | max:0.03 | max:0.10 | min:5*(C+N) max:0.70 |
Balance |
Mechanical Properties Of 321/321H Flanges
| Grade | Tensile Strength ksi (min.) |
Yield Strength 0.2% Offset ksi (min.) |
Elongation - % in 50 mm (min.) |
Hardness (Brinell) MAX |
|---|---|---|---|---|
| 321/321H | 75 | 30 | 40 | 217 |
Physical Properties of 321/321H SS Flanges
| Denstiy lbm/in3 |
Coefficient of Thermal Expansion (min/in)-°F |
Thermal Conductivity BTU/hr-ft-°F | Specific Heat BTU/lbm -°F | Modules of Elasticity (annealed)2-psi | |
|---|---|---|---|---|---|
| at 68 °F | at 68 – 212°F | at 68 – 1832°F | at 200°F | at 32 – 212°F | in tension (E) |
| 0.286 | 9.2 | 20.5 | 9.3 | 0.12 | 28 x 106 |
Our SS 321H Flanges Supplier are used in a wide range of applications and various industries. Below are a few of them:
Application Industries
Aerospace Industry
Food Processing Industry
Pulp & Paper Indusry
Energy Industry
Pharmaceuticals Industry
Power Plant Industry
Chemical Industry
Oil and Gas Industry
Get clear answers to common queries about our steel products, services, and delivery processes.
SS 321H flanges are used to create secure, pressure-rated connections between pipes, valves, pumps and other equipment in systems operating at elevated temperatures. They are commonly selected for petrochemical, chemical processing and thermal applications.
Both grades are titanium-stabilized stainless steels, but 321H contains a higher carbon level than 321. This gives SS 321H better high-temperature strength, making it more suitable for applications involving prolonged exposure to elevated temperatures.
SS 321H combines good corrosion resistance with enhanced strength at elevated temperatures. Its titanium stabilization also helps reduce susceptibility to intergranular corrosion following exposure to high temperatures.
Forged SS 321H flanges are commonly manufactured according to ASTM A182/A182M, depending on the required material specification and application. Dimensional requirements may be based on standards such as ASME B16.5 and other applicable international specifications.
Common options include Weld Neck, Slip-On, Blind, Threaded, Socket Weld, Lap Joint, Orifice and Long Weld Neck flanges. The suitable design depends on the pipe connection, pressure rating and installation requirements.
They can be supplied in different ASME pressure classes, including 150#, 300#, 600#, 900#, 1500# and 2500#, along with applicable PN-rated options. The correct rating depends on operating pressure, temperature and piping specifications.
SS 321H flanges are available in a wide range of nominal pipe sizes. The actual size range depends on the flange type, pressure class and applicable manufacturing standard, while custom requirements can be evaluated for specific projects.
Typical applications include petrochemical plants, chemical processing units, heat exchangers, furnace systems, thermal-processing equipment, refineries and high-temperature piping networks.
Selection should consider pipe size, operating pressure, temperature, flange type, facing, material grade, applicable standard and service medium. These factors determine the appropriate configuration for safe and reliable operation.
For an accurate quotation, provide the material grade, nominal size, flange type, pressure class, facing, applicable standard, quantity and required dimensions. Project drawings, inspection requirements and certification needs can also be shared when applicable.
Our Location
Flat no 5, Swapna HSG Soc
Ltd., Charkop, Kandivali West,
Mumbai, Maharashtra, India.
400067
