Stainless Steel 321 Pipe Manufacturer, Supplier & Exporter in India — Nishra Overseas

Nishra Overseas is a leading Stainless Steel 321 Pipe manufacturer in India, and a dependable 321 Pipe supplier and exporter in India, serving boiler, exhaust, aerospace-adjacent, and high-temperature process industries across domestic and international markets. Whether you're sourcing Stainless Steel 321 Pipe in India for a single project or for ongoing supply, our stock depth and manufacturing capability are built to support both.

321 is an austenitic grade stabilized with titanium — a deliberate addition (minimum 5×(C+N), up to 0.70%) that ties up carbon in the alloy before it can precipitate out as chromium carbide at grain boundaries during welding. That single feature is what 321 exists to solve: it was developed specifically to prevent the intergranular corrosion that standard 304 can be susceptible to, especially in equipment that sees repeated welding and sustained heat. Stainless Steel 321 pipe carries a minimum tensile strength of 515 MPa and a minimum yield strength of 205 MPa, with elongation up to 40% and a density of roughly 8027 kg/m³.

With a melting range around 1398–1446°C and reliable service from roughly 800°C up to 1500°C in the right applications, 321 is a natural fit for boilers, jet engine components, and exhaust systems — anywhere sustained high heat combines with a welded assembly. It's also non-magnetic, cannot be hardened by hot working, and performs well at low temperatures, which broadens its use beyond pure high-heat service. As a trusted Stainless Steel 321 Pipe manufacturer, supplier, and exporter in India, Nishra Overseas' goal is straightforward: deliver certified, high-quality 321 pipe and tube at fair, competitive pricing, backed by dependable stock availability.

Table of Contents

1. 321 Pipe Specification
2. Technical Reference Data
3. Available Product Types
4. Indicative Pricing
5. Packaging & Marking
6. Applications
7. Stock Range by Product
8. Manufacturing & Processing Capabilities
9. Stock Availability
10. Dimensions & Pressure Ratings
11. Stainless Steel 321 Pipe Manufacturer, Supplier & Exporter in India
12. Frequently Asked Questions

321 Pipe Specification

• Outside Diameter: 6.00 mm OD up to 914.4 mm OD, with sizes up to 24" NB held ex-stock.
• Wall Thickness Range: 0.3 mm to 50 mm, covering Schedules 5, 10, 40, 80, 80S, 160, XS, and XXS, along with non-standard thicknesses manufactured to order.
• Product Forms: Seamless pipe, ERW pipe, welded pipe, fabricated pipe, cold-drawn welded (CDW) tube, and LSAW/seam-welded/redrawn tube.
• Shapes: Round, square, rectangular, coiled, "U"-shaped, pancake coils, and hydraulic tubing.
• Length Options: Single random, double random, or cut-to-length. Ends can be supplied plain, beveled, or threaded.
• Surface Finish: 2B, No.4, No.1, or No.8 mirror polish, or any finish specified by the customer — including grit 120–600 finishes on request. End protection is provided using plastic caps as standard.
• Delivery Condition: Annealed and pickled, polished, bright annealed, or cold drawn. Also available in AMS/ASTM, 2D, and annealed finishes for exhaust and tubing applications.
• Documentation: Every consignment can be supported by mill test certificates, EN 10204 3.1 reports, chemical and mechanical test reports, PMI reports, visual and third-party inspection reports, NABL-accredited lab reports, and destructive/non-destructive testing records as required.
• Packing: Wooden crates, plastic wrapping, steel strapping, or custom packing per client instruction.
• Sourcing options: Nishra Overseas can supply Indian-origin material or, on request, material of European, Japanese, US, Korean, Thai, or Taiwanese mill origin, depending on the specification and certification your project requires.
• Size range: 1/2" NB up to 24" OD.

Governing Standards

• ASTM A312 / ASME SA312 — Seamless and straight-seam welded austenitic pipe for high-temperature and general corrosive service; no filler metal permitted.
• ASTM A358 — Electric fusion welded pipe for corrosive/high-temperature duty, typically up to 8" NB, with filler metal permitted.
• ASTM A790 — Seamless and straight-seam welded duplex (ferritic-austenitic) pipe, emphasizing stress corrosion cracking resistance.
• ASTM A409 — Straight- or spiral-seam EFW large-diameter light-wall pipe, 14"–30", Sch 5S/10S.
• ASTM A376 — Seamless austenitic pipe for high-temperature service.
• ASTM A813 / A814 — Welded austenitic pipe for high-temperature and general corrosive applications, including cold-worked variants.

Technical Reference Data

Chemical Composition (%)

Grade	C (max)	N (max)	Ni	Si (max)	P (max)	S (max)	Mn (max)	Cr	Ti
321	0.08	0.10	9.00–12.00	1.00	0.045	0.030	2.00	17.0–19.0	Min. 5×(C+N), max 0.70

The titanium addition is 321's defining feature — it stabilizes the carbon in the alloy so it doesn't precipitate as chromium carbide at grain boundaries during welding, which is what prevents the intergranular/weld-decay corrosion that plain 304 can suffer from.

Mechanical Properties

Grade	Tensile Strength (min, MPa)	Elongation (min, %)	Yield Strength 0.2% Proof (min, MPa)	Hardness (HRB max)	Hardness (HB max)
321	515	40	205	95	217

Physical Properties

Property	Value
Density	~8027 kg/m³
Elastic Modulus (tension)	193 GPa
Melting Range	~1398°C – 1446°C
Magnetic Behavior	Non-magnetic (cannot be hardened by hot working)

Cross-Reference to Other Standards

Grade	UNS	Euronorm No.
321	S32100	1.4541

Governing designations: ASTM A312 / ASME SA312.

Available Product Types

Nishra Overseas maintains stock and production capability across a broad selection of 321 forms:

• PVC-filmed 321 pipe and tube
• Hot-rolled, high-luster 321 pipe for decorative applications
• ASTM 321 welded pipe
• Mirror-polished seamless 321 pipe
• Bright-finish seamless and welded 321 pipe
• 321 seamless pipe to ASTM A312
• Rectangular 321 pipe, prime quality
• Flexible corrugated 321 pipe with insulation layer
• Custom-size spiral-welded 321 pipe
• Thin-wall, large-diameter 321 tube — including exhaust tubing
• Capillary and instrumentation-grade 321 tube
• Schedule 40 seamless 321 pipe (thin-wall, low-pressure applications)
• Cold-rolled seamless 321 pipe
• Sanitary-grade 321 pipe (ASTM A312)
• High-precision 321 pipe
• Coil tube and embossed/colored-finish 321 pipe

Indicative Pricing

Pricing for SS 321 pipe and tube varies by wall thickness, finish, order volume, and current raw-material rates — the titanium addition typically puts 321 at a modest premium over standard 304. As a general market range:

Product Category	Approximate Range
Standard seamless/welded pipe	US $700 – 3,900 / Ton
Thick-wall / capillary / specialty pipe	US $1,000 – 4,000 / Ton or Kg
Mirror-polished / decorative pipe	US $1,000 – 5,000 / Ton
Corrugated / flexible pipe	US $1 – 3.5 / Meter
Piece-rate fittings and small components	US $1 – 80 / Piece

For an accurate, order-specific quotation based on size, schedule, finish, and quantity, please contact our sales team directly.

Packaging & Marking

Standard packaging uses wooden pallets or crates with waterproof paper and plastic wrapping, or seaworthy export packing for larger-diameter pipe, adjusted to match each client's requirements.

Every length of Nishra Overseas 321 pipe is marked along its full length with:

• Nominal pipe size (NB)
• Schedule / wall thickness
• Governing specification and grade
• Method of manufacture (seamless or welded)
• Heat number
• Manufacturer's name or symbol

Test Certification

• Manufacturer's Test Certificate
• IBR Test Certificate (Form III-D)
• Laboratory Test Certificate from a government-approved lab
• Third-party inspection certification, with excise gate pass where applicable for Modvat benefit

Applications

SS 321 pipe from Nishra Overseas is used across:

• Boilers and high-temperature process piping
• Jet engine components and aerospace-adjacent equipment
• Exhaust systems and exhaust tubing
• Applications requiring resistance to post-weld carburization or pitting
• Food processing equipment
• Heat exchangers
• Kitchen benches, sinks, troughs, and appliances
• General construction
• Threaded fasteners
• Chemical containers and transport vessels
• Automotive trim
• Architectural applications
• Railway cars
• Woven and welded screens for mining, quarrying, and water filtration

Stock Range by Product

Nishra Overseas stocks the following 321 product families:

• Shapes: Square pipe · Round pipe · Rectangular pipe
• Finishes: Colour-coated pipe · Ornamental tube · Electropolished pipe
• Specialty Profiles: Slot round pipe · Triangular tube · Hexagonal tube
• Fabricated Forms: Handrail tube · U-shaped tube · Thin-wall seamless tube
• Precision Products: Inner/outer polished pipe · Capillary tube · Seamless tube
• Standards-Referenced Products: AISI 321 seamless pipe · AISI 321 welded pipe · SUS 321 seamless pipe · AISI 321 ERW pipe · UNS S32100 pipe · DIN 1.4541 pipe

Manufacturing & Processing Capabilities

• Structural Cutting — Pipe, tube, tubing, and square/rectangular/round sections cut from 1/16" up to 28" diameter.
• Tubular Cutting — Ornamental tube, tubing, and hollow bar, in the same 1/16"–28" diameter range.
• Production Cutting — Precision cutting for diameters up to 4", carried out on Amada production equipment for tight-tolerance work.
• Structural Polishing — OD and ID polishing available across the full tubular product range.

Stock Availability

Product Form	OD Range	Wall Thickness Range
General pipe stock	6 mm – 630 mm	0.5 mm – 30 mm
Round pipe (large size)	12.7 mm – 300 mm	0.5 mm – 30 mm
Rectangular pipe	10×20 mm – 100×200 mm	0.5 mm – 30 mm
Standard tube	6 mm – 630 mm	0.5 mm – 30 mm
Polished tube	12.7 mm – 250 mm	0.5 mm – 30 mm
Precision tube	16 mm – 85 mm	0.5 mm – 3.0 mm
Capillary tube	13 mm – 85 mm	0.5 mm – 2.0 mm
Instrumentation tube	20 mm – 200 mm	0.5 mm – 2.0 mm
Fine-bore tube	22×0.7 mm – 108×2.0 mm	0.5 mm – 2.0 mm
Hydraulic tube	12.5 mm – 203.2 mm	1.0 mm – 5 mm
Thin-wall tube	0.28 mm – 10 mm	0.08 mm – 1.2 mm
Cold-drawn tube	6 mm – 430 mm	0.8 mm – 30 mm

Schedule Availability by Nominal Bore

NB Size	Sch 5	Sch 10	Sch 40	Sch 80	Sch 160
1/8"–3/8"	✓	✓	✓	✓	—
1/2"–4"	✓	✓	✓	✓	✓
5"	✓	✓	✓	✓	—
6"	✓	✓	✓	✓	✓

Dimensions & Pressure Ratings

SS 321 Pressure Rating by Schedule and Temperature (psi)

Pipe Size	Schedule	100°F	200°F	300°F	400°F	500°F	600°F	650°F	700°F	750°F
1"	40	3048	2629	2362	2171	2019	1924	1867	1824	1810
1"	80	4213	3634	3265	3002	2791	2659	2580	2528	2501
1"	160	6140	5296	4759	4375	4068	3876	3761	3684	3646
1.5"	40	2257	1947	1750	1608	1496	1425	1383	1354	1340
1.5"	80	3182	2744	2466	2267	2108	2009	1949	1909	1889
1.5"	160	4619	3984	3580	3291	3060	2916	2829	2772	2743
2"	40	1902	1640	1474	1355	1260	1201	1165	1141	1129
2"	80	2747	2369	2129	1957	1820	1734	1682	1648	1631
2"	160	4499	3880	3486	3205	2980	2840	2755	2699	2671
3"	40	1806	1558	1400	1287	1196	1140	1106	1084	1072
3"	80	2553	2202	1979	1819	1691	1612	1564	1532	1516
3"	160	3840	3312	2976	2736	2544	2424	2352	2304	2280
4"	40	1531	1321	1187	1091	1014	967	938	919	909
4"	80	2213	1909	1715	1577	1466	1397	1355	1328	1314
4"	160	3601	3106	2791	2566	2386	2273	2206	2161	2138
5"	40	1342	1158	1040	956	889	847	822	805	797
5"	80	1981	1709	1535	1411	1312	1250	1213	1189	1176
5"	160	3414	2945	2646	2433	2262	2155	2091	2049	2027
6"	40	1219	1052	945	869	808	770	747	732	724
6"	80	1913	1650	1483	1363	1267	1208	1172	1148	1136
6"	160	3289	2836	2549	2343	2179	2076	2014	1973	1953
8"	40	1073	926	832	765	711	678	657	644	637
8"	80	1692	1459	1311	1205	1121	1068	1036	1015	1005
8"	160	3175	2738	2460	2262	2103	2004	1944	1905	1885
10"	40	974	840	755	694	645	615	596	584	578
10"	80	1609	1388	1247	1147	1066	1016	986	966	956
10"	160	3147	2714	2439	2242	2085	1986	1927	1880	1868

Note: values above are indicative allowable pressures per common reference tables and should be verified against project-specific engineering data before use in design calculations — particularly at the upper end of 321's temperature range, where sensitization and stabilization behavior become more relevant to check with your engineer.

Stainless Steel 321 Pipe Manufacturer, Supplier & Exporter in India

Nishra Overseas is a manufacturer, stockist, supplier, and exporter of SS 321 seamless and welded pipes, tubes, and fittings, supplying boiler fabricators, exhaust and aerospace-adjacent manufacturers, and trading partners across India and abroad. Whatever stage of the supply chain you're sourcing from, Nishra Overseas covers it end to end.

Stainless Steel 321 Pipe Manufacturer in India

As a Stainless Steel 321 Pipe manufacturer in India, Nishra Overseas produces seamless and welded 321 pipe to ASTM A312 / ASME SA312 and related standards, with non-standard diameters, wall thicknesses, lengths, and end finishes made to drawing or specification on request. Every batch is traceable to a heat number, with mill test certificates, EN 10204 3.1 documentation, and third-party inspection available wherever the order calls for it.

Stainless Steel 321 Pipe Supplier in India

As a Stainless Steel 321 Pipe supplier in India, Nishra Overseas holds ready inventory across common and non-standard sizes out of our warehouse, so smaller or urgent orders can be fulfilled without waiting on a fresh production run. Our technical team helps match pipe schedule, wall thickness, and finish to your specific high-temperature and post-weld corrosion requirements before you place an order.

Stainless Steel 321 Pipe Exporter in India

As a Stainless Steel 321 Pipe exporter in India, Nishra Overseas packs every export consignment to seaworthy standard, with documentation prepared in advance for customs clearance in the destination market. We regularly ship 321 pipe and tube to buyers across the Middle East, Southeast Asia, Africa, and Europe, alongside our domestic supply base.

Industries served: Boiler manufacturing, exhaust and automotive systems, aerospace-adjacent fabrication, food processing, and general high-temperature process industries.

Get a quote: Share your required size, schedule, length, and quantity, and the Nishra Overseas team — your Stainless Steel 321 Pipe manufacturer, supplier, and exporter in India — will respond with current pricing, lead time, and available certification for your order.