High Quality Stainless Steel 347/347H Pipes & Tubes
Seamless • Welded • Durable & Precise
Get a QuoteWhat is 347 & 347H Stainless Steel?
347 stainless steel is a niobium-stabilized austenitic stainless steel designed for improved intergranular corrosion resistance following exposure to temperatures in the chromium carbide precipitation range. 347H is the high-carbon variation of 347 stainless steel, offering enhanced high-temperature strength. These grades are particularly suitable for applications involving welding or operating at high temperatures where sensitization is a concern.
347 Stainless Steel
Chromium (Cr)
Nickel (Ni)
Carbon (C) Max
Manganese (Mn) Max
Silicon (Si) Max
Phosphorus (P) Max
Sulfur (S) Max
Niobium (Nb)
Iron (Fe)
347H Stainless Steel
Chromium (Cr)
Nickel (Ni)
Carbon (C)
Manganese (Mn) Max
Silicon (Si) Max
Phosphorus (P) Max
Sulfur (S) Max
Niobium (Nb)
Iron (Fe)
Types of Stainless Steel 347 & 347H Pipes & Tubes
As premier manufacturers in the industry, we specialize in producing both stainless steel 347/347H seamless pipes & tubes and stainless steel 347/347H welded pipes & tubes, offering comprehensive solutions for high-temperature and corrosive applications.
Manufactured from solid billets through an extrusion process, these pipes deliver superior strength and exceptional pressure resistance at elevated temperatures. Seamless construction eliminates weld seams, making them the preferred choice for critical high-temperature applications including boilers, superheaters, heat exchangers, and aircraft components where welding integrity is paramount and resistance to intergranular corrosion is essential.
These pipes provide an economical alternative with availability across a broader spectrum of sizes and dimensions. Welded pipes excel in high-temperature structural applications, furnace parts, refinery equipment, and general corrosive service conditions where reliable welded joints and stabilization against carbide precipitation are essential. Their cost-effectiveness makes them ideal for projects with budget constraints without compromising high-temperature performance.
Specification of Stainless Steel 347/347H Seamless & Welded Pipes And Tubes
| Specification | Details |
|---|---|
| Stainless Steel Pipe Specification | ASTM A312, A358 / ASME SA312, SA358 |
| SS Tube Specification | ASTM A213, A269, A249, A511, A554 / ASME SA213, SA269, SA249, SA511, SA554 |
| Pipe Size | 1/8” NB to 24” NB, 1/4” OD to 24” OD sizes |
| Tube Size | 1/2″ OD to 8″ OD |
| Thickness Range | 0.3mm – 50 mm, SCH 5, SCH10, SCH 40, SCH 80, SCH 80S, SCH 160, SCH XXS, SCH XS |
| Type | Seamless / ERW / Welded / Fabricated Pipes |
| Form | Round, Square, Rectangular, Oval, Hydraulic Etc |
| Length | Single Random, Double Random & Required Length |
| End | Plain End, Beveled End, Threaded |
| End Protection | Plastic Caps |
| Outside Finish | 2B, No.4, No.1, No.8 Mirror Finish for Stainless Steel Pipes, Finish as per customer Requirements |
| Delivery Condition | Annealed and Pickled, Polished, Bright Annealed, Cold Drawn |
| Inspection, Test Reports | Mill Test Certificates, EN 10204 3.1, Chemical Reports, Mechanical Reports, PMI Test Reports, Visual Inspection Reports, Third Party Inspection Reports, NABL Approved Lab Reports, Destructive Test Report, Non Destructive Test Reports |
| Packing | Packed in Wooden Boxes, Plastic Bags, Steel Strips Bundled, or as per Customers Requests |
| Specials | Sizes and Specifications other than above can be manufactured on request |
STAINLESS STEEL PIPE & TUBES SCHEDULE DIMENSIONS WALL THICKNESS, WT./MTR. (KG)
Click to expand ▼
Stainless Steel 347/347H Pipe Dimensions & Weight Chart
| OD (mm) | WT (mm) | NPS (dn) | Schedule | Weight (kg/m) |
|---|---|---|---|---|
| 13.72 | 1.65 | 1/4″ | 10S | 0.50 |
| 13.72 | 2.24 | 1/4″ | 40S | 0.64 |
| 13.72 | 3.02 | 1/4″ | 80S | 0.81 |
| 17.15 | 1.65 | 3/8″ | 10S | 0.64 |
| 17.15 | 2.31 | 3/8″ | 40S | 0.86 |
| 17.15 | 3.20 | 3/8″ | 80S | 1.12 |
| 21.34 | 2.11 | 1/2″ | 10S | 1.02 |
| 21.34 | 2.77 | 1/2″ | 40S | 1.29 |
| 21.34 | 3.73 | 1/2″ | 80S | 1.65 |
| 26.67 | 2.11 | 3/4″ | 10S | 1.30 |
| 26.67 | 2.87 | 3/4″ | 40S | 1.71 |
| 26.67 | 3.91 | 3/4″ | 80S | 2.23 |
| 33.40 | 2.77 | 1″ | 10S | 2.13 |
| 33.40 | 3.38 | 1″ | 40S | 2.54 |
| 33.40 | 4.55 | 1″ | 80S | 3.29 |
| 48.26 | 2.77 | 1.1/2″ | 10S | 3.16 |
| 48.26 | 3.68 | 1.1/2″ | 40S | 4.11 |
| 48.26 | 5.08 | 1.1/2″ | 80S | 5.49 |
| 60.33 | 2.77 | 2″ | 10S | 3.99 |
| 60.33 | 3.91 | 2″ | 40S | 5.52 |
| 60.33 | 5.54 | 2″ | 80S | 7.60 |
| 88.90 | 3.05 | 3″ | 10S | 6.56 |
| 88.90 | 5.49 | 3″ | 40S | 11.47 |
| 88.90 | 7.62 | 3″ | 80S | 15.51 |
Stainless Steel 347/347H Tube Size Chart
| Wall Thickness (in) | Available Sizes (in) |
|---|---|
| 0.028″ | 1/16″; 1/8″; 3/16″; 1/4″; 5/16″; 3/8″ |
| 0.035″ | 1/8″; 3/16″; 1/4″; 5/16″; 3/8″; 1/2″; 5/8″; 3/4″; 1″; 1-1/4″; 1-1/2″; 2″ |
| 0.049″ | 1/8″; 3/16″; 1/4″; 5/16″; 3/8″; 1/2″; 5/8″; 3/4″; 1″; 1-1/4″; 1-1/2″; 2″ |
| 0.065″ | 3/16″; 1/4″; 5/16″; 3/8″; 1/2″; 5/8″; 3/4″; 1″; 1-1/4″; 1-1/2″; 2″ |
| 0.083″ | 1/4″; 5/16″; 3/8″; 1/2″; 5/8″; 3/4″; 1″; 1-1/4″; 1-1/2″; 2″; 2-1/2″; 3″ |
| 0.095″ | 1/4″; 3/8″; 1/2″; 5/8″; 3/4″; 1″; 1-1/4″; 1-1/2″; 2″; 2-1/2″; 3″ |
| 0.120″ | 1/2″; 5/8″; 3/4″; 1″; 1-1/4″; 1-1/2″; 2″; 2-1/2″; 3″ |
Pressure Ratings for SS 347/347H Tubing (PSIG)
| OD (in) | WT 0.028″ | WT 0.035″ | WT 0.049″ | WT 0.065″ | WT 0.083″ | WT 0.095″ | WT 0.109″ | WT 0.120″ |
|---|---|---|---|---|---|---|---|---|
| 1/8″ | 7,900 | 10,100 | N/A | N/A | N/A | N/A | N/A | N/A |
| 1/4″ | 3,700 | 5,800 | 7,900 | 9,500 | N/A | N/A | N/A | N/A |
| 5/16″ | N/A | 3,700 | 5,400 | 7,300 | N/A | N/A | N/A | N/A |
| 3/8″ | N/A | 3,100 | 4,400 | 6,100 | N/A | N/A | N/A | N/A |
| 1/2″ | N/A | 2,300 | 3,200 | 4,400 | N/A | N/A | N/A | N/A |
| 3/4″ | N/A | N/A | 2,100 | 2,900 | 3,900 | 4,500 | N/A | N/A |
| 1″ | N/A | N/A | N/A | 2,200 | 2,900 | 3,400 | 3,900 | 4,300 |
Chemical Composition of Stainless Steel 347/347H Pipes and Tubes
| Element | 347 Stainless Steel (%) | 347H Stainless Steel (%) |
|---|---|---|
| Carbon (C) | 0.08 max | 0.04 – 0.10 |
| Manganese (Mn) | 2.00 max | 2.00 max |
| Phosphorus (P) | 0.045 max | 0.045 max |
| Sulfur (S) | 0.030 max | 0.030 max |
| Silicon (Si) | 0.75 max | 0.75 max |
| Chromium (Cr) | 17.00 – 19.00 | 17.00 – 19.00 |
| Nickel (Ni) | 9.00 – 13.00 | 9.00 – 13.00 |
| Niobium (Nb) | 10xC min | 8xC min |
| Nitrogen (N) | 0.10 max | 0.10 max |
| Iron (Fe) | Balance | Balance |
Mechanical Properties of Stainless Steel 347/347H Pipes and Tubes
| Grade | Tensile Strength (MPa) min | Yield Strength (0.2% Offset) (MPa) min | Elongation (% in 2″) min | Hardness |
|---|---|---|---|---|
| 347 | 515 | 205 | 40 | Rockwell B (95) max Brinell (201) max |
| 347H | 515 | 205 | 40 | Rockwell B (95) max Brinell (201) max |
Physical Properties of Stainless Steel 347/347H Pipes and Tubes
| Grade | Density (kg/m³) | Elastic Modulus (GPa) | Mean Coefficient of Thermal Expansion (μm/m°C) | Thermal Conductivity (W/m.K) | Specific Heat 0-100°C (J/kg.K) | Electrical Resistivity (nΩ.m) |
|---|---|---|---|---|---|---|
| 347/347H | 7980 | 200 | 16.2 (0-100°C) 17.8 (0-538°C) 18.9 (0-1000°C) |
14.9 (at 100°C) 18.6 (at 500°C) |
500 | 720 |
Equivalent Grades for Stainless Steel 347/347H Pipes and Tubes
| STANDARD | WERKSTOFF NR. | UNS | JIS | AFNOR | BS | GOST | EN |
|---|---|---|---|---|---|---|---|
| SS347 | 1.4550 | S34700 | SUS347 | Z6CNNb18-10 | 347S31 | 08Ch18N12B | X6CrNiNb18-10 |
| SS347H | 1.4961 | S34709 | SUS347H | Z8CNNb18-12 | 347S51 | 08Ch18N12B | X7CrNiNb18-10 |
💡 Practical Difference in Use
Use 347 when: superior intergranular corrosion resistance is required after welding or high-temperature exposure, particularly for continuous service up to 800°C. → Example: welded chemical process equipment, aircraft exhaust systems, heat exchangers.
Use 347H when: enhanced high-temperature strength and creep resistance are needed above 500°C, especially for prolonged service. → Example: superheater tubes, boiler components, high-temperature pressure vessels, refinery heaters.
Uses of 347/347H Stainless Steel Pipes
The uses are defined by its excellent high-temperature strength, oxidation resistance, and superior resistance to intergranular corrosion. Pipes are used in high-temperature and corrosive environments where welding is required.
- High-Temperature Process Piping: This is its primary function. It’s used for moving hot gases, steam, and process fluids in elevated temperature applications, particularly where welding cannot be avoided.
- Heat Exchanger and Boiler Tubes: 347/347H pipes are extensively used in heat exchangers, superheaters, and boiler systems where thermal stability and weld integrity are critical.
- Welded Fabrications in High-Temperature Service: Superior for applications requiring extensive welding where niobium stabilization provides better resistance to intergranular corrosion than titanium-stabilized grades.
When to Choose 347H vs. 347?
This is a critical question for high-temperature applications. 347 is suitable for most high-temperature welded services, while 347H offers enhanced strength at elevated temperatures.
Choose 347 when:
- Applications require superior stabilization against chromium carbide precipitation during welding.
- Service temperatures typically range from 400°C to 800°C with frequent thermal cycling.
- Excellent intergranular corrosion resistance with niobium stabilization is required.
Upgrade to 347H when:
- Superior high-temperature strength and creep resistance are required above 500°C.
- Applications involve prolonged exposure to temperatures between 500°C and 870°C.
- Higher carbon content for improved high-temperature mechanical properties in heavy section components is needed.
Industries That Use 347/347H Stainless Steel Pipes
Virtually every industry that requires high-temperature and corrosion-resistant piping with superior welded joint integrity uses 347/347H. Here are the most prominent ones:
This industry values 347 for its excellent high-temperature performance and superior welded joint integrity.
Uses
Aircraft exhaust systems, engine components, afterburner parts, and high-temperature hydraulic lines requiring welding.
Why 347/347H?
Superior oxidation resistance and strength retention at high temperatures. Niobium stabilization provides better resistance to intergranular corrosion in welded sections compared to titanium-stabilized grades.
This industry demands materials that can withstand extreme temperatures and pressures with reliable welded joints.
Uses
Superheater tubes, boiler components, heat exchanger tubes, and high-temperature steam lines in thermal and nuclear power plants.
Why 347H?
Enhanced creep strength and oxidation resistance at temperatures up to 870°C make it ideal for power plant applications requiring welded construction.
For handling corrosive chemicals at elevated temperatures in welded process equipment.
Uses
Catalyst tubes in reformers, furnace tubes, heat exchanger tubing, and high-temperature process piping requiring extensive welding.
Why 347/347H?
Superior resistance to intergranular corrosion in welded conditions and good general corrosion resistance at high temperatures.
Critical for high-temperature processing units in oil refineries where welded construction is unavoidable.
Uses
Transfer lines in fluid catalytic cracking units, heater tubes, and high-temperature piping systems requiring field welding.
Why 347/347H?
Excellent resistance to sensitization in welded joints and good mechanical properties at refinery operating temperatures up to 870°C.
Essential for furnace components and high-temperature processing equipment requiring welded fabrication.
Uses
Radiant tubes, muffles, retorts, annealing covers, and furnace structural components with welded joints.
Why 347H?
Superior high-temperature strength and resistance to thermal cycling make it suitable for continuous furnace operation with welded construction.
Used in nuclear power plant components requiring superior welded joint integrity.
Uses
Primary coolant piping, steam generator tubing, and high-temperature components in nuclear reactors.
Why 347?
Excellent resistance to intergranular corrosion in welded conditions and good radiation resistance for nuclear applications.
Used in high-temperature sterilization and process systems requiring clean welded joints.
Uses
Sterilizer piping, autoclave systems, and high-temperature process lines requiring welded construction and cleanability.
Why 347?
Good corrosion resistance to sterilizing agents and superior resistance to intergranular corrosion in welded sections.
Used in high-temperature recovery boilers and chemical recovery systems.
Uses
Smelt spouts, recovery boiler tubing, and high-temperature chemical processing equipment.
Why 347H?
Excellent resistance to sulfidation and superior high-temperature strength in aggressive chemical environments.
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