ASTM A213 and ASME SA213 standards cover the SS 347H seamless tubes for high-temperature applications.
ASTM A213 Stainless Steel 347H Seamless Tube Manufacturer
We, Zhejiang Xintongda Special Steel (XTD), are a leading stainless steel 347H seamless tube manufacturer and a global supplier. This Stainless steel 347H tube is a columbium (niobium)-stabilised austenitic stainless steel with higher carbon content (0.04–0.10%). It also consists of chromium (17.0–19.0%), nickel (9.0–13.0%) and manganese (around 2.0%). We manufacture this tube in adherence to the ASTM A213 standard. The higher carbon content of this tube enhances creep strength above 1000°F (538°C). This makes it superior in high-temperature, creep-resistant applications to standard grades like SS 304 or 316. This UNS S34709 tube has exceptional oxidation resistance and thermal stability. This makes it preferred for high-temperature stainless steel environments, such as power generation, aerospace, and petrochemical refineries. Our tubes undergo strict quality checks before delivery. We have an ISO-certified quality management system and can customise this tube for a wide range of applications. We have an annual supply capacity of 25000 tons and supply this tube in about a week for stock orders.
As a trusted 347H Stainless steel tube supplier we ensure our tubes meet these specifications:
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Standard ASTM A213 
OD Range 6.35-257 mm -
Thickness 0.89-12.7 mm -
Length ≤ 22 m
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Technical Data
Technical Data
Manufacturing Process of SS 347H Seamless Tube
The manufacturing process of 347H seamless stainless steel tube starts by heating high-quality steel billets and then piercing them to create hollow shells. Then, cold drawing or cold rolling is done to get the precise size and smooth finish required for industrial use. To learn more about our seamless tube manufacturing process, explore this page.
What are the Key Features of 347H Stainless Steel Seamless Tube?
SS 347H tube has 5 primary features. These are oxidation & sulfidation resistance, high-temperature performance, enhanced creep resistance, high-carbon ("H" Grade) and intergranular corrosion resistance. Each feature is explained below in detail:
- Oxidation & Sulfidation Resistance: This tube has chromium (17.00–19.00%) and nickel (9.00–13.00%) in it, which forms a protective layer on the surface. This shield stops the tube from reacting with sulfur or oxygen in high-heat environments.
- High-Temperature Performance: Even when exposed to very high temperatures for long periods of time the 347H stainless steel tube maintains its mechanical strength. This stability ensures that the tube doesn't deform or fail during intense thermal cycles.
- Enhanced Creep Resistance: Adding niobium (Nb≥8*C%) to the tube makes it stronger and less likely to deform over time when under constant high stress. It is designed to stay strong and preserve its shape at temperatures where other steels soften.
- High-Carbon ("H" Grade): The 'H' in this tube's name indicates higher carbon content compared to the standard TP347 grade. This specific chemistry gives the extra strength needed for high-pressure service at high temperatures.
- Intergranular Corrosion Resistance: Columbium stabilisation prevents chromium carbide precipitation during the welding process. This ensures the metal remains resistant to corrosion along its grain boundaries in harsh chemical settings.
ASTM A213 TP347H Tube Equivalent Material
ASTM A213 TP347H tube is commonly known as UNS S34709. Some of its global equivalents include DIN 1.4961 and JIS SUS347H.
| GRADE | UNS | GB | JIS | ISO | DIN/EN | GOST | |
| ISC | NEW | ||||||
| 347H | S34709 | S34779 | 07Cr18Ni11Nb | SUS347H | X6CrNiNb18-10 | 1.4961 | 08X18H12Б |
100% Certified Testing & Documentation
- EN 10204 3.1 and EN 10204 3.2 Material Test Certificates (MTC)
- Raw Materials Certificate
- 100% PMI
- Heat Treatment Charts
- Third-Party Inspection Report
- Surface roughness and size measurement
- Manufacturer Test Certificate (Impact Testing, Flattening, Flare, Bend, Hardness, Intergranular, Pitting Corrosion, Grain size, ET, UT, HT)
- Laboratory Test Certificate from the Government-Approved Lab
Industries and Application of 347H Stainless Steel Tubes?
There are 8 industrial applications where ASME SA213 TP347H stainless steel tubes are commonly used.
Heat Exchanger Tubes
This tube facilitates efficient heat transfer between two fluids while resisting high internal pressures. Its thermal stability prevents cracking during the constant temperature shifts found in industrial exchangers.
Aircraft Exhaust Stacks and Collector Rings
The SS 347H tube handles extremely hot exhaust gases coming directly from aircraft engines. It is chosen as it can withstand high vibration and heat without scaling or oxidising.
Heavy Wall-Welded Equipment
This thick-walled tube is used to build large-scale machinery that operates under immense pressure. The 347H grade is ideal here as it often eliminates the need for post-weld annealing in many applications.
Boiler Tubes and Casings
This UNS S34709 seamless tube carries water or steam through the hottest sections of industrial boilers. It provides the necessary strength to prevent bursting while exposed to direct flames and high heat.
Radiant Superheaters
The tube is used in power plants to heat saturated steam to much higher temperatures. Its high creep strength ensures the coils do not sag or leak under extreme thermal stress.
Cabin Heaters
In the aviation and automotive sectors, this seamless 347H tubing safely transports hot air to warm passenger cabins. The material ensures no exhaust fumes leak into the air supply due to metal fatigue.
Oil and Gas Refinery Piping
Refineries use this tube to move corrosive hydrocarbons through high-temperature cracking units. The tube resists the sulfur compounds often found in crude oil during the refining process.
Chemical Production Equipment
The DIN 1.4961 tube is used in reactors and vessels that handle organic and inorganic chemical solutions. The 347H grade protects the equipment from corrosive damage during high-temperature chemical reactions.
Frequently Asked Questions
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Which ASTM standards cover SS 347H seamless Tubes?
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What is the maximum operating temperature for stainless steel 347H tubes?347H is designed for continuous service above 1000°F and is commonly used up to approximately 1500°F, depending on operating conditions.