Stainless Steel 321 Pipe Manufacturer in India
Stainless Steel 321 Pipe Manufacturer in India
Sachiya Steel International is an ISO 9001:2015 and TÜV-certified Stainless Steel 321 Pipe Manufacturer in India, established in 2005. We make seamless and welded 321 pipe (UNS S32100, EN 1.4541) and 321H for lines that run hot, cycle between heat and cold, or are welded in service. Titanium in the steel locks up carbon, so the pipe resists intergranular corrosion where ordinary 304 would fail. Every order comes with an EN 10204 3.1 mill test certificate.
We supply 321 pipe to ASTM A312, A358 and A376 in sizes from ⅛ inch to 24 inches, solution annealed and pickled before dispatch. Refineries, power plants, petrochemical units and exhaust system builders use it where temperatures sit between 450°C and 900°C, and we ship to buyers in 85+ countries. Each batch is traceable to its heat number. Send us your size, schedule and operating conditions, and we will quote to your drawing.
What Is Stainless Steel 321 Pipe?
Stainless Steel 321 Pipe is made from a titanium-stabilised stainless steel grade designed to handle high temperatures while maintaining good corrosion resistance. It contains chromium and nickel, while titanium helps protect the material against harmful carbide formation during welding and heating. This makes SS 321 pipes suitable for exhaust systems, heat exchangers, boilers, chemical processing equipment, and other applications exposed to elevated temperatures. They offer good strength, durability, and resistance to intergranular corrosion under suitable operating conditions.
Stainless Steel 321 Pipes
High-quality Stainless Steel 321 pipes manufactured for demanding applications across chemical, petrochemical, power generation, aerospace, marine and engineering industries. Available in multiple sizes, schedules and manufacturing specifications.
Why Choose Stainless Steel 321 Pipe?
The main reason is stability in the heat. Ordinary stainless steel loses corrosion resistance if it sits between roughly 450°C and 850°C, because chromium carbides form along the grain boundaries. 321 avoids this because titanium carbides form first. The steel stays resistant to intergranular corrosion after welding and after long hot service.
The second reason is performance at temperature. 321 resists scaling in air up to about 900°C and keeps good strength where 304L starts to soften. It also copes well with repeated heating and cooling, which breaks down many other grades.
The third reason is value. 321 gives you reliable high-temperature performance without the cost of nickel alloys, and it welds and forms in the same way as other austenitic grades. For hot lines, exhausts and refinery pipework, that makes it a practical, widely accepted choice.
Types of Stainless Steel 321 Pipe
As a Stainless Steel 321 Pipe Manufacturer, we offer different pipe types to suit high-temperature operations, pressure requirements, and industrial processing needs. Each type serves a specific purpose based on its manufacturing method, wall thickness, and working conditions.
- Seamless SS 321 Pipe: Made without a welded joint and suitable for high-temperature and pressure applications when designed to the required specifications.
- Welded SS 321 Pipe: Manufactured by forming and welding stainless steel strips for industrial piping and general service.
- EFW SS 321 Pipe: Produced using electric fusion welding and suitable for applications requiring larger pipe sizes.
- Heavy Wall SS 321 Pipe: Features thicker walls for demanding operating conditions and specific pressure requirements.
- SS 321H Pipe: A higher-carbon variant designed to provide improved creep strength during prolonged exposure to elevated temperatures.
- Cut-to-Length and Bent SS 321 Pipe: Prepared to specified lengths or bent according to project drawings for easier installation.
The right pipe type depends on operating temperature, pressure, dimensions, and applicable industry standards. Selecting the correct specification helps ensure safe and reliable performance.
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→Get Certified Stainless Steel 321 Pipes at Competitive Factory Prices
Stainless Steel 321 Pipe Specifications
| Parameter | Details |
|---|---|
| Material | Stainless Steel 321 / UNS S32100 / 1.4541, and 321H / S32109 |
| Titanium limit | 5 × (C + N) minimum, 0.70% maximum (321); 4 × (C + N) minimum (321H) |
| Product forms | Seamless, ERW, EFW, TIG welded |
| Pipe size | ⅛" NPS to 24" NPS |
| Wall thickness | 1.65 mm to 25 mm |
| Schedules | 5S, 10S, 40S, 80S, 160, XXS and custom |
| Delivery condition | Solution annealed and pickled |
| Length | Single random, double random, cut length up to 12 m |
| Ends | Plain, beveled, threaded |
| Tests | Chemical analysis, tensile, flattening, hydrotest or eddy current, PMI |
| Extra tests on request | IGC, ultrasonic, radiography |
| Documents | EN 10204 3.1 mill certificate, inspection reports |
Stainless Steel 321 Pipe Standards
| Standard | What it covers |
|---|---|
| ASTM A312 / ASME SA312 | Seamless and welded austenitic pipe, TP321 and TP321H |
| ASTM A358 / ASME SA358 | EFW pipe for high-temperature service |
| ASTM A376 / ASME SA376 | Seamless pipe for high-temperature central-station service |
| ASTM A213 / ASME SA213 | Seamless boiler, superheater and heat exchanger tubes |
| ASTM A249 / ASME SA249 | Welded boiler and heat exchanger tubes |
| ASME B36.19M | Dimensions of stainless steel pipe |
| EN 10216-5 / EN 10217-7 | European seamless and welded stainless tubes |
| JIS G3459 | Japanese stainless steel pipes |
Material and Grades of Stainless Steel 321 Pipe
321 (S32100): The standard titanium-stabilised grade, with carbon up to 0.08%. It suits hot and welded service from about 450°C to 900°C.
321H (S32109): Higher carbon, between 0.04% and 0.10%, for better strength and creep resistance in long hot service. It is often specified for pressure piping above 500°C.
321/321H dual certified: One pipe that meets both chemistries, which lets a single stock serve both specifications.
All 321 pipe is supplied solution annealed and pickled. If your design needs a stabilising heat treatment, which is common in some refinery services, tell us at enquiry and we will confirm what can be supplied.
Stainless Steel 321 vs 304L vs 347 Pipe: Which One Do You Need?
| Point | 321 | 304L | 347 |
|---|---|---|---|
| Stabiliser | Titanium | None (low carbon) | Niobium |
| Carbon limit | 0.08% max | 0.03% max | 0.08% max |
| Strength at 450–850°C | Good | Lower | Good |
| Resists intergranular corrosion after heat | Yes | Only at lower temperatures | Yes |
| High polish | Not ideal, titanium can streak | Good | Good |
| Cost | Moderate | Lowest | Higher |
Choose 321 for hot, welded lines in the 450–900°C range. Choose 304L when the pipe is welded but runs cool. Choose 347 when the pipe needs a clean polished surface or sees heavy radiation or very high service temperatures.
Stainless Steel 321 Pipe Chemical Composition
| Element | TP321 (%) | TP321H (%) | EN 1.4541 (%) |
|---|---|---|---|
| Carbon (C) | 0.08 max | 0.04 – 0.10 | 0.08 max |
| Manganese (Mn) | 2.00 max | 2.00 max | 2.00 max |
| Silicon (Si) | 1.00 max | 1.00 max | 1.00 max |
| Phosphorus (P) | 0.045 max | 0.045 max | 0.045 max |
| Sulphur (S) | 0.030 max | 0.030 max | 0.015 max |
| Chromium (Cr) | 17.0 – 19.0 | 17.0 – 19.0 | 17.0 – 19.0 |
| Nickel (Ni) | 9.0 – 12.0 | 9.0 – 12.0 | 9.0 – 12.0 |
| Titanium (Ti) | 5×(C+N) min, 0.70 max | 4×(C+N) min, 0.70 max | 5×C min, 0.70 max |
| Nitrogen (N) | 0.10 max | 0.10 max | — |
| Iron (Fe) | Balance | Balance | Balance |
Stainless Steel 321 Pipe Mechanical Properties
| Property | Value |
|---|---|
| Tensile strength | 515 MPa min |
| Yield strength (0.2%) | 205 MPa min |
| Elongation | 35% min |
| Hardness | 90 HRB max (192 HBW) |
| Density | About 7.9 g/cm³ |
| Melting range | About 1400 – 1425°C |
| Elastic modulus | About 193 GPa |
| Thermal expansion (0–100°C) | About 16 – 17 µm/m·°C |
| Magnetic response | Non-magnetic when annealed |
High-Temperature Performance of Stainless Steel 321 Pipe
| Service condition | What to expect |
|---|---|
| Below 425°C | Any austenitic grade works. 304L is often the cheaper pick. |
| 425°C to 850°C | The range 321 is made for. Titanium prevents carbide formation, so welds and heat-affected zones stay corrosion resistant. |
| Up to about 900°C in air | Good scaling resistance, including under repeated heating and cooling. |
| Above about 900°C | Look at 309, 310S or nickel alloys for better scaling and strength. |
| Refinery shutdowns | Stabilised grades like 321 resist polythionic acid attack, which attacks unstabilised steels after long heat exposure. |
| 650°C to 900°C for very long periods | Sigma phase can form and reduce toughness once the pipe cools. Check design needs. |
Stainless Steel 321 Pipe Size and Weight Chart
Theoretical weight is (OD − Wall) × Wall × 0.02491, giving kg per metre with dimensions in mm. Real weight varies slightly within mill tolerance.
OD and wall are in mm. Multiply the result by the pipe length to obtain the total weight.
| NPS | OD (mm) | Sch 5S wall (mm) | Sch 5S kg/m | Sch 80S wall (mm) | Sch 80S kg/m |
|---|---|---|---|---|---|
| ¾" | 26.7 | 1.65 | 1.03 | 3.91 | 2.22 |
| 1¼" | 42.2 | 1.65 | 1.67 | 4.85 | 4.51 |
| 2" | 60.3 | 1.65 | 2.41 | 5.54 | 7.56 |
| 3" | 88.9 | 2.11 | 4.56 | 7.62 | 15.43 |
| 4" | 114.3 | 2.11 | 5.90 | 8.56 | 22.55 |
| 6" | 168.3 | 2.77 | 11.42 | 10.97 | 42.99 |
| 8" | 219.1 | 2.77 | 14.93 | 12.70 | 65.30 |
| 10" | 273.1 | 3.40 | 22.84 | 12.70 | 82.38 |
| 12" | 323.9 | 3.96 | 31.56 | 12.70 | 98.45 |
Stainless Steel 321 Pipe Sizes, Dimensions and Schedules
A pipe is named by its nominal size, but its wall depends on the schedule. Hot lines are often specified in heavier schedules, because heat and pressure together stress the wall. The table shows how wall changes with schedule at two common sizes. DN is the metric size for each NPS.
| Schedule | Wall at 1½" / DN 40 (mm) | Wall at 8" / DN 200 (mm) | Typical use |
|---|---|---|---|
| 5S | 1.65 | 2.77 | Light-duty, low-pressure ducts |
| 10S | 2.77 | 3.76 | Exhaust and flue lines |
| 40S | 3.68 | 8.18 | Standard hot process piping |
| 80S | 5.08 | 12.70 | Steam and higher-pressure lines |
| 160 | 7.14 | 23.01 | Very high pressure |
Typical outside diameter tolerance for ASTM A312 pipe is below.
| Pipe size (NPS) | OD tolerance (mm) |
|---|---|
| ⅛" to 1½" | +0.4 / −0.8 |
| Over 1½" to 4" | +0.8 / −0.8 |
| Over 4" to 8" | +1.6 / −0.8 |
| Over 8" to 18" | +2.4 / −0.8 |
Wall thickness tolerance is −12.5% on A312 pipe. We also cut, bend and prepare ends to your drawing.
Testing and Inspection of Stainless Steel 321 Pipe
| Test | Purpose |
|---|---|
| Chemical analysis | Confirms titanium sits at or above 5×(C+N), and below 0.70%, with chromium and nickel in range |
| Tensile and hardness | Checks strength, elongation and hardness |
| Flattening | Shows the pipe deforms without cracking |
| Hydrostatic or eddy current | Finds leaks and hidden defects |
| PMI | Confirms the alloy and titanium presence before dispatch |
| IGC to ASTM A262 | Checks resistance to intergranular attack, on request |
| Ultrasonic or radiography | Extra checks for EFW and heavy-wall pipe, on request |
| Dimensional and visual | Checks OD, wall, length, straightness and surface |
Common Materials Supplied with Stainless Steel 321 Pipe
High-temperature piping projects often require different stainless steel grades and heat-resistant alloys to suit varying operating conditions. As stainless steel 321 pipe suppliers, we offer a range of related materials for applications in refineries, power plants, furnaces, and chemical processing facilities.
SS 321H: Suitable for applications that need improved creep strength during long periods of high-temperature operation.
SS 347 and 347H: Used in refinery equipment, power plants, and hot process piping.
SS 304H and 316H: Selected for applications requiring strength at elevated temperatures.
SS 316Ti: Offers molybdenum-based corrosion resistance and titanium stabilisation for suitable industrial environments.
SS 309S and 310S: Designed for high-temperature service in furnaces, heat treatment equipment, and industrial heating systems.
Alloy 800H/HT: Nickel-iron-chromium alloys used in demanding high-temperature environments, including applications involving carburising gases.
The right material depends on operating temperature, corrosion exposure, pressure, and project specifications. Matching the material to its working conditions helps support reliable performance and longer service life.
Applications of Stainless Steel 321 Pipe
- Oil Refining: Heater, reformer and hydrocracker piping that sees heat and sulphur compounds.
- Petrochemical: Cracker furnace lines and high-temperature process piping.
- Power Generation: Superheater sections, steam lines and flue gas ducts.
- Chemical Processing: Hot transfer lines and reactor connections.
- Exhaust and Emission Systems: Manifolds, headers and exhaust lines for engines and turbines.
- Heat Treatment and Furnaces: Radiant tubes, muffles and furnace piping.
- Expansion Joints and Bellows: Hot flexible connections that cycle with temperature.
- Aerospace and Automotive: Exhaust ducting and hot-section tubing.
Why Choose Us as Your Stainless Steel 321 Pipe Manufacturer in India?
You should choose us because we are a certified manufacturer that makes 321 pipe itself. We hold ISO 9001:2015 and TÜV certifications, and we have been in stainless steel manufacturing since 2005. Because we make the pipe, you deal directly with the manufacturer, which keeps pricing clear and delivery dates honest. As a Stainless Steel 321 Pipe Manufacturer and Supplier in India, we look after everything from grade selection to dispatch.
You should also choose us because we control what makes 321 work. Every heat is checked so titanium is at least five times carbon plus nitrogen, and not above 0.70%. For 321H, carbon is checked inside the 0.04–0.10% band. PMI confirms the alloy before the pipe leaves our plant, and the results go on the certificate so your inspector can verify them.
Our range is wide enough to cover a full project. We make seamless, ERW, TIG welded and EFW 321 and 321H pipe from ⅛ inch to 24 inches, in ASTM A312, A358 and A376, in standard and heavy schedules. Custom sizes, cut lengths and bends are made to your drawing, and we supply the 347, 316H, 310S and nickel alloy pipe that goes alongside it, under one set of documents.
Finally, you can choose us because we are used to demanding buyers. Every order includes an EN 10204 3.1 certificate, and PMI, IGC testing and third-party inspection are available on request. We export to 85+ countries, so audits, witnessed inspections and export paperwork are part of our everyday work.
Countries We Export Stainless Steel 321 Pipe To
As a Stainless Steel 321 Pipe Manufacturer and Supplier in India, we export to 85+ countries, serving oil and gas, refining, power generation, petrochemical and chemical industries.
Middle East: UAE, Saudi Arabia, Qatar, Oman, Kuwait and Bahrain.
Europe: Germany, Italy, United Kingdom, Netherlands, France, Spain, Belgium and Poland.
Asia-Pacific: Singapore, Malaysia, Indonesia, Thailand, Vietnam, South Korea, Japan and Australia.
Americas: USA, Canada, Mexico, Brazil and Chile.
Africa: South Africa, Nigeria, Egypt and Kenya.
South Asia: Nepal, Bangladesh and Sri Lanka.
EN 10204 3.1 mill test certificates come with every order. EN 10204 3.2 certification and third-party inspection can be arranged on request. We pack each shipment to suit its route and destination, and we prepare the shipping and export documents your project requires, so international orders move cleanly from our plant to your site.
FAQs
Common questions about SS 321 pipe, titanium stabilisation, high-temperature service and supply.
Why does 321 contain titanium?
Titanium combines with carbon before chromium can. That keeps chromium in the steel, so the pipe resists intergranular corrosion after welding or long heat exposure.
When should I use 321 instead of 304L?
Use 321 when the pipe runs hot, between about 450°C and 900°C, or is exposed to repeated heating. Use 304L when the pipe is welded but runs cool.
How is 321 different from 347?
321 uses titanium as the stabiliser, while 347 uses niobium. 347 is better for high polish and heavy radiation, and 321 is usually the lower-cost choice for hot lines.
Can 321 pipe be polished?
It can be polished, but titanium particles can leave faint streaks on a mirror finish. For a high polish, 347 or 304L is usually a better choice.
What is the maximum temperature for 321 pipe?
321 resists scaling in air up to about 900°C. For long service near the top of that range, design strength limits and the applicable code also apply.
How does 321H differ from 321?
321H has higher carbon, between 0.04% and 0.10%, which gives better creep strength in long hot service. 321 has up to 0.08% carbon.
Which standard should I specify for 321 pipe?
Use ASTM A312 for general pipe. Use A376 for high-temperature central-station pipe, A358 for EFW pipe and A213 for exchanger tubes.
How do I calculate the weight of 321 pipe?
Use (OD − Wall) × Wall × 0.02491, with both values in mm, to get kg per metre. Multiply by length for total weight.
Which documents come with an order?
EN 10204 3.1 mill test certificates are included. Inspection reports, PMI reports and third-party certificates are available on request.