Stainless Steel 347
Plate, Pipe, Tube & Bar | ASTM A240 / A312 / A479
Niobium-stabilized stainless steel for high-temperature, high-pressure applications. Available globally from China, Europe, and UAE.
Updated: July 2025
347 Plate | Size: 1500 × 3000 mm | Thickness: 3 – 25 mm
3.85
5.10
4.30
347 Seamless Pipe | OD: Custom | Wall: Variable
6.70
8.10
7.50
347 Round Bar | Dia: 10–150 mm
4.90
6.30
5.50
Product Form Minimum Order
** Trial orders available for EPC and industrial users – subject to lead time & surcharge.
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- Plate, pipe, and round bar in stock – mill-certified, high-temp resistant
Forms: Plate / Seamless Pipe / Welded Pipe / Round Bar / Tube
Standards: ASTM A240, A312, A479
UNS: S34700
W.Nr.: 1.4550
Property
value
FAQs
It’s ideal for high-temperature applications like heat exchangers, refinery piping, and exhaust systems where resistance to intergranular corrosion is essential.
Unlike 304/316, 347 is stabilized with niobium to prevent carbide precipitation during welding or thermal cycling — making it superior in high-temperature welded structures.
Yes. Thanks to niobium stabilization, 347 can be welded with minimal risk of intergranular corrosion. No post-weld heat treatment is usually needed.
Yes, when supplied in accordance with ASTM and ASME specs, 347 is approved for pressure vessels operating at elevated temperatures.
347H has higher carbon content, improving its strength at elevated temperatures. Use 347H in sustained high-temp pressure systems; 347 for general HT service.
Non-Destructive Testing (NDT):
Destructive Testing (DT):
Certifications:
• EN 10204 3.1 MTC
• TPI Accepted: SGS, BV, TUV
• ASME Boiler Code available on request
** Full traceability & documentation for EPC / refinery / pressure service
Smart Message
Stainless Steel 347 – Stable Performance at High Temperatures
Niobium-stabilized stainless for excellent intergranular corrosion resistance and high-temperature strength. Preferred in refinery and thermal systems.
• For elevated temperature & pressure vessels
• Niobium-stabilized for carbide control during welding
• For high-temp pipelines and refinery systems
• Requires hydrotest & NDT
• Used in heat exchangers, bolting, and structural parts
• Supplied annealed – hot or cold finished