Stainless Steel 321 Seamless Pipes Manufacturer in India

What are Stainless Steel 321 Seamless Pipe?

Stainless Steel 321 Seamless Pipes are titanium-stabilized austenitic stainless steel pipes designed for applications requiring good corrosion resistance and reliable performance at elevated temperatures. The addition of titanium helps stabilize the material against chromium carbide precipitation during prolonged exposure to high temperatures.

Manufactured without a longitudinal weld seam, Stainless Steel 321 Seamless Pipes provide uniform construction for demanding pressure and process piping systems. The combination of chromium, nickel and titanium provides good oxidation resistance, strength, toughness and resistance to intergranular corrosion under suitable service conditions.

Stainless Steel 321 Seamless Pipes are used in heat exchangers, chemical processing equipment, petrochemical plants, power generation systems, thermal processing equipment and other industrial applications involving elevated temperatures. They are available in different outside diameters, wall thicknesses, schedules and lengths according to applicable standards and project requirements.

Kamal Steels is a Stainless Steel 321 Seamless Pipes Manufacturer & Stockist in India, supplying SS 321 Seamless Pipes in standard and customized sizes, schedules, wall thicknesses and lengths. Products can be supplied with applicable testing, inspection, material certificates and documentation according to customer and project specifications.

stainless steel 321 seamless pipe specifications

Table of Contents

Stainless Steel 321 Seamless Pipe Specifications

Specification Details
Product Name Stainless Steel 321 Seamless Pipe
Grade SS 321 / Type 321
UNS S32100
EN Grade 1.4541
Material Type Titanium-Stabilized Austenitic Stainless Steel
Manufacturing Process Seamless
Product Standard ASTM A312
ASME Specification ASME SA312
Size Range 1/8" to 24" and above as required
Schedule 5S, 10S, 40S, 80S, 160 and other schedules
Wall Thickness As per applicable schedule or specified requirement
Length Random, Double Random or Fixed Length
End Type Plain End, Bevelled End or Threaded End as required
Surface Finish Pickled & Passivated, Annealed, Bright Annealed or Polished
Heat Treatment Solution Annealed and Rapidly Cooled as specified by the applicable standard
Testing Hydrostatic, PMI, Ultrasonic, Flattening, Flaring and other applicable tests
Inspection Third Party Inspection available as required
Certification EN 10204 3.1 / Material Test Certificate (MTC)
Packaging Bundles, Wooden Cases, Wooden Boxes, Plastic End Caps and Export Packing

Stainless Steel 321 Seamless Pipe Size Chart

NPS / Size Outside Diameter (OD) Common Use
1/8" 10.3 mm Instrumentation & Small Bore Lines
1/4" 13.7 mm Process Instrumentation
1/2" 21.3 mm Utility & Process Piping
3/4" 26.7 mm Industrial Fluid Transfer
1" 33.4 mm Process Equipment Connections
1 1/4" 42.2 mm Chemical Processing Lines
1 1/2" 48.3 mm Heat Exchanger Connections
2" 60.3 mm General Industrial Service
3" 88.9 mm Refinery & Petrochemical Plants
4" 114.3 mm Process & Utility Piping
6" 168.3 mm High Temperature Service Lines

Actual dimensions and tolerances vary depending on the applicable ASTM standard, nominal pipe size, and schedule selected for the project.

Stainless Steel 321 Seamless Pipe Weight Chart

The theoretical weight of Stainless Steel 321 Seamless Pipes depends on the outside diameter, wall thickness, schedule, and pipe length. Higher wall thickness results in increased weight per meter and greater pressure handling capability.

NPS / Size SCH 10 Weight (kg/m) SCH 40 Weight (kg/m) SCH 80 Weight (kg/m)
1/2" 0.63 0.84 1.10
3/4" 0.80 1.12 1.48
1" 1.01 1.40 1.81
1 1/4" 1.28 1.79 2.35
1 1/2" 1.45 2.16 2.86
2" 1.92 2.99 3.93
3" 3.05 4.70 6.39
4" 4.38 6.47 8.63
6" 7.31 10.75 14.32

The above values are approximate theoretical weights. Actual supplied weights may vary depending on manufacturing tolerances, applicable specifications, wall thickness, and production methods.

Stainless Steel 321 Seamless Pipe Schedule Chart

Schedule Wall Type Typical Use
SCH 5S Light Wall Low-pressure process and instrumentation piping
SCH 10S Light Wall General industrial and process piping systems
SCH 40S Medium Wall Chemical plants, refineries and utility piping
SCH 80S Heavy Wall High-pressure and elevated-temperature applications
SCH 160 Extra Heavy Wall Critical industrial and severe service conditions

Wall thickness varies according to the nominal pipe size and applicable dimensional standards. The appropriate schedule should be selected based on operating pressure, temperature, corrosion allowance and project design requirements.

ASTM A312 TP321 Seamless Pipe

ASTM A312 TP321 Seamless Pipe is a titanium-stabilized austenitic stainless steel pipe intended for high-temperature and corrosive service applications. Designated as UNS S32100, Grade 321 contains titanium additions that reduce chromium carbide precipitation during welding and prolonged exposure to elevated temperatures. This stabilization provides excellent resistance to intergranular corrosion while maintaining outstanding mechanical strength and oxidation resistance.

ASTM A312 TP321 seamless pipes are widely used in refineries, petrochemical plants, chemical processing facilities, heat exchangers, pressure vessels, power generation, aerospace, thermal processing equipment, and exhaust systems where reliable performance at elevated temperatures is essential.

Kamal Steels supplies ASTM A312 TP321 Seamless Pipes in a wide range of sizes, schedules, wall thicknesses, lengths, end preparations, and surface finishes to satisfy domestic and international industrial requirements.

SS 321 vs SS 304 Pipe

SS 321 and SS 304 are both austenitic stainless steel grades offering excellent corrosion resistance and fabrication properties. However, SS 321 is stabilized with titanium, making it better suited for high-temperature applications where resistance to intergranular corrosion after welding is required. SS 304 is commonly selected for general-purpose industrial applications, while SS 321 is preferred for continuous elevated-temperature service.

Feature SS 321 SS 304
Material Type Titanium Stabilized Austenitic Stainless Steel Standard Austenitic Stainless Steel
UNS Number S32100 S30400
Main Alloying Elements Chromium, Nickel & Titanium Chromium & Nickel
High Temperature Resistance Excellent Good
Intergranular Corrosion Resistance Excellent Moderate after prolonged heating
Weldability Excellent Excellent
Typical Applications Heat Exchangers, Exhaust Systems, Refineries, Furnaces General Industrial & Process Piping
Cost Generally Higher Generally Lower

SS 321 Seamless Pipe vs Welded Pipe

The primary difference between SS 321 seamless and welded pipes lies in their manufacturing process. Seamless pipes are produced without a weld seam, providing superior strength and pressure handling capability, while welded pipes are manufactured by rolling and welding stainless steel strip or plate, making them a cost-effective solution for many industrial applications.

Feature Seamless Pipe Welded Pipe
Manufacturing Produced without a weld seam Manufactured by forming and welding strip
Strength Higher Moderate
Pressure Rating Suitable for high-pressure service Suitable for medium-pressure service
Surface Finish Uniform Visible weld seam after fabrication
Dimensions Smaller production range Available in larger diameters
Cost Higher More economical
Typical Applications Critical Process & High Pressure Systems General Industrial & Structural Applications

The selection between seamless and welded SS 321 pipes depends on operating pressure, temperature, project specifications, dimensional requirements and budget. For critical applications involving high pressure or elevated temperatures, seamless pipes are generally the preferred choice.

Stainless Steel 321 Seamless Pipe Chemical Composition

Stainless Steel 321 Seamless Pipes contain chromium, nickel, and titanium as the principal alloying elements. Titanium acts as a stabilizing element and helps reduce chromium carbide precipitation during prolonged exposure to elevated temperatures. This composition provides good corrosion resistance and supports reliable performance in high-temperature industrial applications.

Element Composition (%)
Carbon 0.08 max.
Chromium 17.0 - 19.0
Nickel 9.0 - 12.0
Titanium 5 × C min. to 0.70 max.
Manganese 2.00 max.
Silicon 1.00 max.
Phosphorus 0.045 max.
Sulfur 0.030 max.

The chemical composition of SS 321 Seamless Pipes should be verified against the applicable ASTM or ASME specification and the material test certificate supplied with the product.

Stainless Steel 321 Seamless Pipe Mechanical Properties

Stainless Steel 321 Seamless Pipes provide a combination of tensile strength, yield strength, ductility, and toughness suitable for demanding industrial piping systems. The titanium-stabilized structure supports reliable performance during elevated-temperature service and helps maintain resistance to intergranular corrosion under suitable conditions.

Mechanical Property Minimum Requirement
Tensile Strength 515 MPa
Yield Strength 205 MPa
Elongation 35%

Actual mechanical properties may vary according to the applicable specification, pipe dimensions, heat-treatment condition, and testing requirements. Final values should be confirmed against the relevant product standard and material test certificate.

Stainless Steel 321 Seamless Pipe Applications

Stainless Steel 321 Seamless Pipes are used in applications requiring corrosion resistance and dependable performance at elevated temperatures. The titanium-stabilized composition makes the grade suitable for certain applications involving prolonged thermal exposure.

Application Typical Use
Heat Exchangers High-temperature heat-transfer piping systems.
Chemical Processing Process piping exposed to elevated temperatures and corrosive media.
Petrochemical Equipment High-temperature process piping and equipment.
Power Generation Process and utility piping systems.
Thermal Processing Equipment Piping and equipment exposed to elevated temperatures.
Furnace Equipment High-temperature piping and related industrial systems.
Industrial Process Systems Corrosion-resistant piping for demanding service conditions.

Industries Using Stainless Steel 321 Seamless Pipes

Stainless Steel 321 Seamless Pipes are used across industries where corrosion resistance, thermal stability, and reliable piping performance are required. The grade is particularly suitable for selected applications involving elevated temperatures and prolonged thermal exposure.

Industry Typical Applications
Chemical Industry High-temperature chemical process piping.
Petrochemical Industry Process piping and high-temperature equipment.
Oil & Gas Industry Selected process and utility piping systems.
Power Generation Industry High-temperature process and utility applications.
Heat Treatment Industry Thermal processing equipment and piping.
Industrial Engineering High-temperature process piping and fabricated systems.
Energy Industry Selected elevated-temperature piping applications.

Kamal Steels supplies Stainless Steel 321 Seamless Pipes in different sizes, schedules, wall thicknesses and lengths according to customer and project requirements.

Frequently Asked Questions

Stainless Steel 321 Seamless Pipes are designed for high-temperature service between approximately 540°C and 870°C. They are widely used in heat exchangers, exhaust systems, refinery equipment, boilers, pressure vessels, and petrochemical processing plants where excellent heat and oxidation resistance are required.

SS 321H contains a higher controlled carbon content (0.04–0.10%) than SS 321, providing improved creep strength and better performance during prolonged exposure to elevated temperatures. SS 321 is commonly used for general high-temperature applications, while SS 321H is preferred for more demanding thermal service.

Yes. SS 321 contains titanium, which stabilizes the material and prevents chromium carbide precipitation during welding and prolonged heating. This gives it better resistance to intergranular corrosion and makes it more suitable than SS 304 for continuous high-temperature service.

ASTM A312 TP321 covers seamless, welded, and heavily cold-worked austenitic stainless steel pipes intended for corrosive service and elevated-temperature applications. It specifies requirements for dimensions, chemical composition, mechanical properties, heat treatment, and testing.

Kamal Steels supplies Stainless Steel 321 Seamless Pipes in outside diameters from 6.00 mm to 914.4 mm, with sizes up to 24" NB available ex-stock. Standard schedules include SCH 5, SCH 10, SCH 40, SCH 80, SCH 80S, SCH 160, and SCH XXS.

SS 321 Seamless Pipes are widely used in refineries, petrochemical plants, heat exchangers, boilers, thermal processing equipment, aircraft exhaust systems, power generation facilities, and chemical processing industries requiring reliable high-temperature performance.

Yes. The titanium stabilization in SS 321 helps prevent carbide precipitation during welding, maintaining corrosion resistance and making the material suitable for welded fabrications exposed to elevated temperatures.

Yes. Every order is supplied with Mill Test Certificates (MTC). Third-party inspection, PMI testing, and complete material traceability documentation are also available upon request.

Yes. We supply SS 321 Seamless Pipes in single random, double random, and custom-cut lengths with finishes including annealed & pickled, bright annealed, polished, and cold drawn to suit specific project requirements.

Kamal Steels is a trusted manufacturer, supplier, stockist, and exporter of ASTM A312 TP321 Seamless Pipes. We offer ready stock, competitive pricing, strict quality control, Mill Test Certificates, third-party inspection, and worldwide delivery support for industrial projects.