Stainless Steel 321H Heat Exchanger Tubes Manufacturer and Supplier

Stainless Steel 321H heat exchanger tubes are titanium-stabilised austenitic stainless steel tubes for continuous high-temperature use between 538°C and 816°C (1000°F to 1500°F). Grade TP321H (UNS S32109) has a higher carbon content (0.04-0.10%) than standard 321, which increases creep strength and resistance to stress rupture at high temperatures. The alloy contains 17.0-19.0% chromium, 9.0-12.0% nickel and titanium at 4×(C+N) minimum to 0.70% maximum. Titanium ties up carbon, preventing intergranular corrosion during long-term heating. The tubes offer a minimum tensile strength of 515 MPa (75 ksi), yield strength of 205 MPa (30 ksi), and a minimum 35% elongation.

Sachiya Steel International, based in Mumbai, India, is a trusted manufacturer, supplier, stockist and exporter of Stainless Steel 321H heat exchanger tubes with over 2 decades of experience. Standard sizes include outer diameters from 6.35 mm to 257 mm, wall thickness from 0.70 mm to 12.7 mm and lengths up to 22 metres. We supply seamless tubes (ASTM A213), welded tubes (ASTM A249), and U-bend tubes for shell-and-tube heat exchangers, condensers and pressure vessels.

Every tube is supplied with mill test certificates as per EN 10204 3.1, and our facility is certified to ISO 9001, ISO 14001 and ISO 45001. This page explains the following in detail:

Specifications
Pricing
Chemical Composition
Mechanical Properties
Equivalent Grades
Applications
321H vs 304H Comparison
Shipping
FAQs

Stainless Steel 321H Heat Exchanger Tubes Specifications

The table below lists key specifications of Stainless Steel 321H heat exchanger tubes, including standards, sizes, forms, finishes and tests for high-temperature industrial use.

Parameter	Details
Standards	ASTM A213 / ASME SA-213 (Seamless Ferritic & Austenitic Alloy Steel Tubes), ASTM A249 / ASME SA-249 (Welded Austenitic Tubes)
OD Range	1/4" (6.35 mm) to 2" (50.8 mm) (typical heat exchanger range)
Wall Thickness	0.028" to 0.120" (0.7 mm to 3.0 mm)
Length	Up to 20 m (straight lengths); U-bends and custom cut lengths available
Forms	Seamless (cold drawn), Welded, U-Tubes
Finish	Annealed & Pickled (AP), Bright Annealed (BA)
Heat Treatment	Solution annealed; stabilised with titanium for high-temperature service
End Type	Plain end, bevelled, deburred
Testing	Eddy Current Test, Hydrostatic Test, Air Under Water Test, PMI
Applications	Heat exchangers, condensers, superheaters, boilers and petrochemical processing

Stainless Steel 321H Heat Exchanger Tube Sizes

SS 321H heat exchanger tubes are stocked in outer diameters from 6.35 mm to 257 mm, wall thickness from 0.70 mm to 12.7 mm and lengths up to 22 metres. Custom sizes are available as per the client's specification.

Dimension	Range
Outer Diameter (OD)	6.35 mm to 257 mm
Wall Thickness (WT)	0.70 mm to 12.7 mm
Length	Up to 22 metres; custom lengths available

Stainless Steel 321H Heat Exchanger Tubes Price

SS 321H heat exchanger tubes cost about INR 520–800 per kg (USD 6–10/kg), depending on size, thickness, quantity and specifications. Very small sizes (below 1½”) and large sizes (above 4”) are costlier. Contact Sachiya Steel International for an exact quote.

Chemical Composition of ASTM A213 / ASME SA-213 TP321H Heat Exchanger Tubes

The table below shows the chemical composition of ASTM A213 / ASME SA-213 TP321H heat exchanger tubes and the main alloying elements that improve their high‑temperature strength and corrosion resistance.

Carbon C

0.04 - 0.10%

Manganese Mn

2.00% max

Phosphorus P

0.045% max

Sulfur S

0.030% max

Silicon Si

1.00% max

Chromium Cr

17.0 - 19.0%

Nickel Ni

9.0 - 12.0%

Titanium Ti

4×(C+N) min, 0.70% max

Nitrogen N

0.10% max

Mechanical Properties of Stainless Steel 321H Heat Exchanger Tubes

ASTM A213 TP321H heat exchanger tubes must have at least 515 MPa (75 ksi) tensile strength, 205 MPa (30 ksi) yield strength, and 35% elongation. These properties help the tubes resist creep and failure during long-term high‑temperature boiler and heat exchanger service.

515 / 75

MPa / ksi (min)

Tensile Strength

205 / 30

MPa / ksi (min)

Yield Strength

35%

(min)

Elongation

Property	Value	Unit
Tensile Strength (min)	515 (75)	MPa (ksi)
Yield Strength (min)	205 (30)	MPa (ksi)
Elongation (min)	35	%

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Equivalent Grades of Stainless Steel 321H Heat Exchanger Tubes

The table below shows the equivalent grades of Stainless Steel 321H heat exchanger tubes in different international standards, making it easier for engineers and buyers around the world to identify and specify the right material.

Designation	Standard / Country
UNS	UNS S32109
X12CrNiTi18-9 / 1.4878 (W.Nr)	Europe (EN / DIN)
SUS 321H	Japan (JIS)

Stainless Steel 321H Heat Exchanger Tube Applications

SS 321H heat exchanger tubes are used where equipment must run for a long time at 538-816°C and resist corrosion between the grain boundaries. Commonly specified in the following industries:

Petrochemical & Refinery Applications

Crude distillation columns, catalytic reformers and hydrocracker exchangers operate under continuous thermal cycling. SS 321H tubes resist sensitisation here because titanium locks carbon away from grain boundaries.

Power Generation Applications

Boiler superheater sections and economiser coils in coal-fired and gas-fired plants rely on TP321H tubing. Creep strength above 538°C exceeds non-stabilised austenitic grades, reducing stress rupture risk during extended service.

Chemical Processing Applications

Nitric acid heat exchangers, organic acid coolers and condenser tubes in chemical plants use SS 321H. Titanium stabilisation prevents carbide precipitation in process streams cycling through the 427-816°C sensitisation range.

Stainless Steel 321H vs SS 304H Heat Exchanger Tubes

SS 321H and SS 304H heat exchanger tubes behave differently at high temperatures and in corrosive conditions. They also form carbides in different ways, which affects which grade is better suited for tough heat and process applications.

Parameter	SS 321H Heat Exchanger Tubes	SS 304H Heat Exchanger Tubes
Material Type	Titanium-stabilised austenitic stainless steel	High-carbon austenitic stainless steel
UNS Designation	S32109	S30409
Key Alloying Feature	Titanium addition stabilises carbon	Higher carbon content (0.04-0.10%)
Intergranular Corrosion Resistance	Excellent; resistant due to Ti stabilisation	Moderate; susceptible in certain conditions
Carbide Precipitation (427-816°C)	Titanium forms stable TiC, preventing Cr depletion	Chromium carbide formation at grain boundaries
High-Temperature Stability	Superior for prolonged exposure	Good, but less stable than 321H
Continuous Service Temperature	Suitable above 538°C and cyclic heating	Suitable up to ~870°C, but risk of sensitization
Weldability	Better resistance to weld decay	Requires post-weld heat treatment in critical applications
Oxidation Resistance	Excellent	Excellent
Typical Applications	High-temperature heat exchangers, superheaters, petrochemical units	Boilers, pressure vessels and general heat exchangers
Cost	Higher	More economical

Shipping & Packaging

Heavy-duty wooden boxes Packing

Export Packaging Standard

We strictly follow seaworthy export handling standards to protect SS 321H heat exchanger tubes from transit damage, moisture ingress, and surface contamination during long-distance dispatch.

Heavy-duty wooden boxes with moisture barrier lining
HDPE stretch film wrapping on all bundles
Plastic end caps on threaded and plain-end pipes
Silica gel desiccants to minimize moisture exposure
ISPM-15 fumigated wooden packaging for export

Tube Bundle Yard Staging

Container End-Cap Protection

Wrapped Export-Ready Bundles

We Export Worldwide

Sachiya Steel International supplies stainless steel products to major industrial markets across North America, Europe, the Middle East, Asia and Africa with export-ready documentation and logistics support.

USA
Canada

Frequently Asked Questions

What sizes are available for SS 321H Heat Exchanger Tubes?+

SS 321H tubes are available with outer diameters from 6.35 mm to 257 mm, wall thickness from 0.70 mm to 12.7 mm and lengths up to 22 metres. Custom sizes can be made to client specifications.

What is the difference between SS 321 and SS 321H Heat Exchanger Tubes?+

SS 321H has a higher carbon content (0.04-0.10%) than SS 321 (0.08% max). This increased carbon improves creep strength for continuous high-temperature service above 538°C.

What is the price of SS 321H Heat Exchanger Tubes per Kg?+

Indicative price is INR 520 to 800 per kg, depending on outer diameter, wall thickness and quantity. Contact Sachiya Steel International for the latest and most accurate quotation.

What ASTM specification covers SS 321H Heat Exchanger Tubes?+

Seamless SS 321H heat exchanger tubes are covered by ASTM A213 / ASME SA-213. Welded SS 321H heat exchanger tubes are covered by ASTM A249 / ASME SA-249.

Can SS 321H Heat Exchanger Tubes be supplied as U-Bend Tubes?+

Yes. SS 321H tubes can be supplied as U-bend tubes per ASTM A213 for shell-and-tube heat exchangers. Each U-bent tube is tested using dye penetrant methods.

What is the maximum service temperature for SS 321H Heat Exchanger Tubes?+

SS 321H tubes can be used continuously up to 816°C (1500°F). Titanium stabilisation prevents intergranular corrosion in the 427–816°C sensitisation temperature range.

What testing is performed on SS 321H Heat Exchanger Tubes?+

Each tube receives hydrostatic or nondestructive electric testing per ASTM A213, plus chemical analysis, tensile, flattening and flaring tests. PMI and intergranular corrosion testing are also routinely performed.