.png)
Stainless Steel 347 / 347H Pipes & Tubes Stockist & Supplier in India
Operating high-temperature steam headers and refinery units without structural failure requires columbium-stabilized alloys designed for creep resistance. As a premier Stainless Steel 347 Pipes & Tubes Stockist in India, Steel Emporium provides precision-engineered Stainless Steel 347 Pipes and Stainless Steel 347 Tubes certified for severe thermal service.
As a leading Stainless Steel 347H Pipes & Tubes Stockist in India, we supply ready-to-ship Stainless Steel 347H Pipes & Tubes in seamless, ERW, and EFW formats. Backed by 25+ years of ISO 9001:2015 expertise, our stock meets ASTM A312, A213, and A358 standards with 100% MTC certification. For titanium-stabilized alternatives, explore our Stainless Steel 321 Pipes & Tubes range.
Jump To Section: Material Specs | Key Advantages | Size Chart | FAQs
ASTM A312 / A213 / A269 SS 347 / 347H Technical Specifications
Our processing facilities deliver precision cold drawing, bright annealing, custom length cutting, and surface polishing across all columbium-stabilized grade variants.
| Technical Parameter | Specification Scope & Manufacturing Capabilities |
|---|---|
| Governing Specifications | ASTM A312, ASTM A213, ASTM A269, ASTM A249, ASTM A358, ASME SA312, ASME SA213, DIN, EN, JIS |
| Grade Variants | Stainless Steel 347 (UNS S34700), Stainless Steel 347H (UNS S34709) |
| Manufacturing Types | Seamless, Welded, ERW, EFW, Cold Drawn (CDW), Hot Finished |
| Profile Configurations | Round, Square, Rectangular, Hydraulic, Custom Shapes |
| Outside Diameter (OD) Scope | Seamless: 6 mm to 114.3 mm OD | Welded / ERW: 10 mm to 114.3 mm OD (1/2" to 24" Nominal) |
| Schedule Wall Thickness Range | SCH 5S, SCH 10S, SCH 20, SCH 30, SCH 40S, STD, SCH 80S, SCH 120, SCH 160, XXS |
| Length & End Treatments | 1m to 12.5m, Custom Cut | Plain, Beveled, Threaded Ends |
| Surface Finish & Coatings | AP (Annealed & Pickled), BA (Bright Annealed), 180–400 Grit Polish, Electropolished |
Key Advantages of Stainless Steel 347 & 347H Pipes & Tubes
High-Temperature Corrosion Protection
Added columbium (niobium) prevents structural weakening and rust formation during intense heat exposure between 425°C and 850°C.
Stronger Under Long-Term Heat
SS 347H contains extra carbon, allowing it to withstand high pressure and extreme heat above 537°C far better than standard stainless grades.
Ready-to-Use After Welding
Strong corrosion resistance is maintained around weld joints without requiring additional heat treatment after welding.
Refinery Stress Resistance
Prevents cracking caused by corrosive sulfur compounds, ensuring safe equipment shutdowns and restarts in oil refineries.
Engineered for High-Heat Durability
SS 347H features a specifically controlled metal grain structure to ensure long-lasting durability in continuous high-temperature service.
Chemical, Mechanical & Equivalent Specifications
| Element / Parameter | SS 347 (UNS S34700) | SS 347H (UNS S34709) |
|---|---|---|
| Carbon (C) | 0.08% Max | 0.04% – 0.10% |
| Manganese (Mn) | 2.00% Max | 2.00% Max |
| Silicon (Si) | 1.00% Max | 1.00% Max |
| Phosphorus (P) | 0.045% Max | 0.045% Max |
| Sulfur (S) | 0.030% Max | 0.030% Max |
| Chromium (Cr) | 17.00% – 20.00% | 17.00% – 19.00% |
| Nickel (Ni) | 9.00% – 13.00% | 9.00% – 13.00% |
| Columbium / Niobium (Cb/Nb) | 10 x C Min to 1.10% Max | 8 x C Min to 1.10% Max |
| Iron (Fe) | 62.74% Min | 63.72% Min |
| Mechanical Property | SS 347 | SS 347H |
|---|---|---|
| Tensile Strength (MPa min / Psi min) | 515 MPa / 75,000 Psi | 515 MPa / 75,000 Psi |
| Yield Strength (0.2% Proof MPa min / Psi min) | 205 MPa / 30,000 Psi | 205 MPa / 30,000 Psi |
| Elongation (% in 50 mm min) | 35% | 40% |
| Hardness (Brinell Max) | 201 HB | 201 HB |
| Hardness (Rockwell B Max) | 92 HRB | 92 HRB |
| Standard / Grade | WERKSTOFF NR. | UNS Number | EN Standard | JIS (Japan) |
|---|---|---|---|---|
| SS 347 | 1.4550 | S34700 | X6CrNiNb18-10 | SUS 347 |
| SS 347H | 1.4961 | S34709 | X6CrNiNb18-12 | SUS 347H |
Stainless Steel 347 / 347H Series Size & Schedule Chart
| Nominal Size (NB) | SCH 5S / 10S Wall | SCH 40S Wall | SCH 80S / 160 Wall |
|---|---|---|---|
| 1/2" NB (21.34 mm OD) | 1.65 mm / 2.11 mm | 2.77 mm | 3.73 mm / 4.78 mm |
| 3/4" NB (26.67 mm OD) | 1.65 mm / 2.11 mm | 2.87 mm | 3.91 mm / 5.56 mm |
| 1" NB (33.40 mm OD) | 1.65 mm / 2.77 mm | 3.38 mm | 4.55 mm / 6.35 mm |
| 1-1/2" NB (48.26 mm OD) | 1.65 mm / 2.77 mm | 3.68 mm | 5.08 mm / 7.14 mm |
| 2" NB (60.32 mm OD) | 1.65 mm / 2.77 mm | 3.91 mm | 5.54 mm / 8.74 mm |
| 3" NB (88.90 mm OD) | 2.05 mm / 3.05 mm | 5.49 mm | 7.62 mm / 11.13 mm |
| 4" NB (114.30 mm OD) | 2.11 mm / 3.05 mm | 6.02 mm | 8.56 mm / 13.49 mm |
| 6" NB (168.28 mm OD) | 2.77 mm / 3.40 mm | 7.11 mm | 9.52 mm / 18.26 mm |
Industrial Applications of SS 347 & SS 347H
The 347 and 347H cluster offers high thermal rupture strength and oxidation protection across critical processing systems.
Power Generation & Utility Boilers (SS 347H)
ASTM A213 TP347H seamless superheater tubes, reheater coils, and high-pressure steam headers operating above 537°C.
Petrochemical & Refinery Heavy Circuits (SS 347 / SS 347H)
Fluid catalytic cracking (FCC) units, hydrocracker piping, and reactor transfer lines exposed to polythionic acid.
Chemical Processing Equipment (SS 347)
Heavy-wall pressure vessels, organic chemical distillation towers, and nitric acid recovery lines requiring columbium stabilization.
Aerospace & Rocket Propulsion (SS 347)
High-temperature engine manifold collector rings, rocket thrust chamber liners, and flexible exhaust joints.
Nuclear Power Facilities (SS 347 / SS 347H)
Core internal piping components and high-temperature heat exchangers demanding long-term microstructural stability.
Quality Assurance, MTC Certification & Testing Standards
Every shipment processed by Steel Emporium undergoes verification under our ISO 9001:2015 & PED 2014/68/EU Quality Policy to guarantee compliance.
| Certification / Standard | Compliance & Testing Scope |
|---|---|
| ISO 9001:2015 & Pressure Scope | Certified QMS with PED 2014/68/EU and AD 2000 Merkblatt approvals. |
| EN 10204 3.1 & 3.2 MTC | Official test reports covering heat numbers, chemical composition, and factory origin tracking. |
| PMI & Lab Verification | 100% XRF spectro testing and NABL-accredited laboratory inspections. |
| Mechanical & Weld NDT | Hydrostatic, eddy current, and flaring tests guarantee 100% seam integrity. |
| Third-Party Inspection (TPI) | Inspection-ready for SGS, TUV, Bureau Veritas, or Lloyds. |
| Registered Corporate Office | 102, Durga Devi Street, Mumbai - 400004, Maharashtra, India |
| Central Warehouse & Stockyard | Plot 943, Kalamboli Steel Market, Navi Mumbai - 410218, Maharashtra, India |
Frequently Asked Questions
Request a Technical Sourcing Quote
Ready to source high-performance 347 or 347H stainless steel piping for your project? Connect with our technical sales specialists today for competitive factory wholesale pricing, MTC documentation, and global export shipping schedules.