ASTM A312 TP 347 is a specification covering stainless steel seamless, welded, and heavily cold‑worked pipes and tubes made from a niobium–stabilized austenitic stainless steel. This grade is defined under the industry standard ASTM A312 / ASME SA312, ensuring consistent quality and performance for high‑temperature and corrosive environments. TP 347 is particularly valued for its ability to resist intergranular corrosion and to maintain strength in extreme heat, making it a preferred choice in demanding engineering applications..
The alloy composition of ASTM A312 TP 347 includes 17–20% chromium and 9–13% nickel, with additions of niobium (columbium) which stabilize the steel’s microstructure. This stabilization reduces carbide precipitation during welding and high‑temperature service, offering improved resistance to sensitization compared with unstabilized alloys. Mechanical properties include a minimum tensile strength of 515 MPa and a yield strength of 205 MPa, with excellent elongation for toughness and ductility..
One of the core strengths of TP 347 pipes and tubes is their wide range of applications. They are widely used in oil and gas processing, chemical and petrochemical industries, power generation, heat exchangers, pharmaceutical equipment, marine environments and high‑temperature processing. Their heat and corrosion resistance also make them suitable for high‑pressure steam and furnace components, where standard grades might fail.
From a form and supply perspective, ASTM A312 TP 347 is available in seamless, ERW (Electric Resistance Welded), and welded constructions, in sizes ranging from small bore tubes to large industrial pipe sizes, with various wall thickness schedules (e.g., SCH 10S, SCH 40S, SCH 80S). Tubes can also be supplied in polished, annealed, and pickled finishes and custom cut lengths to suit precise engineering requirements.
| Standard | ASTM A312 / ASME SA312 |
|---|---|
| Grade | TP 347 (Niobium Stabilized Austenitic Stainless Steel) |
| Product Forms | Seamless (SMLS), ERW, Welded |
| Supply Condition | Annealed, Pickled & Polished (Optional) |
| Manufacturing Process | Hot Rolled / Cold Drawn |
| End Finish | Plain End, Beveled End, Threaded |
| Application | Oil & Gas, Petrochemical, Power Plants, Heat Exchangers, Marine, Pharmaceutical |
Worldwide stockists, suppliers, and distributors — such as Metal Tubular Products and other global steel service centers — maintain inventories of ASTM A312 TP 347 pipes and tubes to support just‑in‑time delivery and bespoke project demands. These are critical for global supply chains serving energy projects, refineries, petrochemical plants, and offshore infrastructure. Suppliers also often provide related components like TP 347 flanges, fittings, and welded assemblies to support integrated piping solutions
In summary, ASTM A312 TP 347 Pipes & Tubes are engineered for excellence in corrosive and high‑temperature service. Their robust chemical properties, versatile supply forms, and widespread availability from stockists and manufacturers worldwide make them a strategic material in heavy‑duty industrial applications.
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.08 max |
| Manganese (Mn) | 2.0 max |
| Phosphorus (P) | 0.045 max |
| Sulfur (S) | 0.03 max |
| Silicon (Si) | 1.0 max |
| Chromium (Cr) | 17–20 |
| Nickel (Ni) | 9–13 |
| Niobium (Nb) | ≥ 10 x C |
| Iron (Fe) | Balance |
| Property | Value |
|---|---|
| Yield Strength | 205 MPa (min) |
| Tensile Strength | 515 MPa (min) |
| Elongation | 40% (min) |
| Hardness | ≤ 95 HRB |
| Nominal Pipe Size (NPS) | Outside Diameter (mm) | Schedule 10S Wall (mm) | Schedule 40S Wall (mm) | Schedule 80S Wall (mm) |
|---|---|---|---|---|
| 1/2" | 21.3 | 2.11 | 2.77 | 3.91 |
| 1" | 33.4 | 2.31 | 3.38 | 4.55 |
| 2" | 60.3 | 2.77 | 3.91 | 6.02 |
| 4" | 114.3 | 3.38 | 6.02 | 8.56 |
| 6" | 168.3 | 3.91 | 7.11 | 11.13 |
| Standard | Equivalent Grade |
|---|---|
| UNS | S34700 |
| EN | X10CrNiNb18-9 / 1.4550 |
| JIS | STS 347 |
| DIN | 1.4550 |
ASTM A312 TP 347 Pipes & Tubes are primarily used in **chemical, petrochemical, power generation, and high-temperature applications**. They are ideal for transporting **corrosive fluids, steam, and gases**, and are widely applied in **refineries, heat exchangers, boilers, and industrial piping systems** due to their excellent corrosion resistance and high-temperature strength.
The designation “TP 347” indicates a **stabilized austenitic stainless steel grade** containing niobium (columbium) to improve **creep and intergranular corrosion resistance**. It is suitable for welding and high-temperature service.
Yes, ASTM A312 TP 347 Pipes & Tubes are available in **both seamless (SMLS) and welded forms**. They meet stringent chemical composition and mechanical property requirements, making them suitable for **critical applications**.
ASTM A312 TP 347 Pipes & Tubes are manufactured in various forms such as **Seamless (SMLS), ERW, LSAW, and SSAW**, allowing flexibility for different **pressure ratings, diameters, and project requirements**.
ASTM A312 TP 347 Pipes & Tubes are stocked and supplied worldwide by **Metal Tubular Products**, offering a **wide size range, fast delivery**, and full compliance with **international quality standards** for global industrial projects.
We export steel pipes and tubes to over 60 countries worldwide, serving clients across Asia, Europe, the Middle East, Africa, Oceania, and the Americas. Our strong global logistics network ensures reliable delivery, quality assurance, and compliance with international standards.
Export Destinations Include:
Afghanistan, Albania, Andorra, Angola, Austria, Australia, Bahrain, Bangladesh,
Bhutan, Brazil, Brunei, Belarus, Belgium, Bulgaria, Cambodia, China, Cyprus,
Croatia, Czech Republic, Canada, Denmark, Estonia, Egypt, Finland, France,
Germany, Greece, Georgia, Hungary, Iceland, Ireland, Italy, Indonesia, Iran,
Iraq, Israel, Japan, Jordan, Kazakhstan, Kuwait, Kyrgyzstan, Lebanon, Latvia,
Latin America, Liechtenstein, Lithuania, Luxembourg, Malta, Madagascar, Mexico,
Moldova, Monaco, Malaysia, Maldives, Mongolia, Myanmar (Burma), Nepal,
New Zealand, North Korea, Netherlands, Norway, Nigeria, Oman, Poland, Portugal,
Pakistan, Palestine, Philippines, Qatar, Russia, Romania, San Marino,
Serbia and Montenegro, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Saudi Arabia, Singapore, South Korea, South Africa, Sri Lanka, Sudan, Syria,
Taiwan, Tanzania, Tajikistan, Thailand, Turkey, Turkmenistan, Ukraine,
United Kingdom, United Arab Emirates (UAE), Uzbekistan, Venezuela, Vietnam,
Yemen, and more.
