Industries that operate boilers, heat exchangers, pressure vessels, and high-temperature piping systems rely on Stainless Steel 347/347H Round Bars for consistent strength and structural integrity. Their ability to maintain mechanical properties under continuous heat exposure makes them a preferred choice in fabrication and heavy engineering sectors worldwide.
Stainless Steel 347 is a columbium-stabilized austenitic stainless steel, while 347H is the high carbon version designed for improved creep resistance at elevated temperatures. The addition of niobium, also known as columbium, stabilizes the alloy by preventing chromium carbide precipitation during welding and high-temperature service. This stabilization enhances resistance to intergranular corrosion, particularly in welded components. The chemical composition of Stainless Steel 347/347H Round Bars typically includes chromium and nickel, similar to 304 grade stainless steel, with added niobium for stabilization. The 347H variant contains higher carbon content to provide better high-temperature strength and creep resistance. These bars exhibit excellent oxidation resistance and mechanical strength at temperatures up to 800 degrees Celsius and beyond in certain conditions. Metallurgically, the fully austenitic structure ensures good toughness, ductility, and non-magnetic characteristics in annealed condition. Stainless Steel 347/347H Round Bars also offer good formability and weldability, making them suitable for fabrication into complex components used in pressure equipment and thermal processing units.
One of the primary advantages of Stainless Steel 347/347H Round Bars is their outstanding resistance to intergranular corrosion. The niobium stabilization minimizes sensitization during welding and high-temperature exposure, making them reliable for critical welded assemblies in chemical processing and power plants. These stainless steel round bars provide excellent high-temperature strength and creep resistance, especially in the 347H grade. This makes them suitable for components exposed to prolonged thermal stress such as furnace parts, boiler tubes, and superheater supports. Their resistance to oxidation ensures long-term durability in elevated temperature environments.
In addition to thermal stability, Stainless Steel 347/347H Round Bars deliver good mechanical strength and structural reliability. They can be machined and fabricated efficiently, supporting cost-effective manufacturing processes. Their long service life reduces maintenance frequency, offering economic benefits in large-scale industrial operations.
In power generation facilities, Stainless Steel 347/347H Round Bars Manufacturers supply high-temperature resistant bars used in boiler components, superheaters, and steam piping systems. The material’s ability to withstand thermal cycling and sustained heat exposure ensures operational efficiency and plant safety. Within petrochemical and refinery sectors, Stainless Steel 347/347H Round Bars Suppliers provide bars for fabrication of heat exchangers, reactor components, and process piping that handle aggressive chemicals and high-pressure fluids. The stabilized composition helps prevent corrosion-related failures in critical process equipment.
For heavy engineering and structural fabrication projects, Stainless Steel 347/347H Round Bars Stockists maintain ready inventory of various diameters and lengths to support immediate project requirements. These bars are widely used in structural supports, high-temperature fasteners, and industrial frameworks exposed to heat and corrosive conditions. In international infrastructure and thermal processing projects, Stainless Steel 347/347H Round Bars Exporters deliver certified materials for use in offshore platforms, cement plants, and chemical processing facilities. Compliance with global standards ensures quality assurance, traceability, and reliable performance across diverse industries.
Stainless Steel 347/347H Round Bars are manufactured in accordance with ASTM A276 and ASTM A479 specifications, which define requirements for stainless steel bars and shapes used in general engineering and pressure vessel applications. For high-temperature and boiler services, ASME SA276 and ASME SA479 are the corresponding standards. These standards specify chemical composition limits, mechanical properties, heat treatment processes, and dimensional tolerances to ensure suitability for pressure equipment, piping systems, and structural components. Compliance with ASTM and ASME requirements guarantees that SS 347 and 347H round bars meet stringent performance criteria for power plants, refineries, and chemical processing units.
Steel products such as round bars, pipes, tubes, plates, sheets, and coils are classified under globally recognized standards including ASTM, ASME, EN, DIN, JIS, and ISO. ASTM and ASME standards are commonly used in North America and the Middle East for pressure vessels, piping, and industrial fabrication. EN and DIN standards govern European material specifications, while JIS standards apply to Japanese industrial products. ISO standards provide international consistency in quality management and testing procedures. Stainless Steel 347 and 347H grades are identified based on alloy composition, stabilization elements, and mechanical performance, enabling engineers and procurement teams worldwide to select the correct material for structural engineering, high-temperature service, and chemical processing applications.
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Request Latest Price & Stock AvailabilityStainless Steel 347 and 347H Round Bars contain controlled amounts of carbon, chromium, manganese, nickel, phosphorus, sulfur, silicon, columbium and tantalum for reliable performance in demanding industrial applications.
| Grade | C | Cr | Mn | Ni | P | S | Si | Cb/Ta |
|---|---|---|---|---|---|---|---|---|
| SS 347 | 0.08 max |
Min: 17.0 Max: 20.0 |
2.0 max |
Min: 9.0 Max: 13.0 |
0.04 max | 0.30 max | 0.75 max |
Min: 10 × C Max: 1.0 |
| SS 347H |
Min: 0.04 Max: 0.10 |
Min: 17.0 Max: 20.0 |
2.0 max |
Min: 9.0 Max: 13.0 |
0.03 max | 0.30 max | 0.75 max |
Min: 10 × C Max: 1.0 |
C: Carbon, Cr: Chromium, Mn: Manganese, Ni: Nickel, P: Phosphorus, S: Sulfur, Si: Silicon, Cb: Columbium and Ta: Tantalum. All listed values represent percentage by weight unless otherwise specified.
The mechanical properties of Stainless Steel 347/347H Round Bars include tensile strength, yield strength, elongation and hardness values for demanding industrial applications.
| Grade |
Tensile Strength ksi (MPa) Min |
Yield Strength 0.2% Offset ksi (MPa) Min |
Elongation (% in 50 mm) Min |
Hardness (Brinell) Max |
Hardness (Rockwell B) Max |
|---|---|---|---|---|---|
| 347/347H |
75 ksi (515 MPa) |
30 ksi (205 MPa) |
40% | 201 | 95 |
These values describe the minimum tensile strength, minimum yield strength, minimum elongation and maximum hardness of Stainless Steel 347/347H Round Bars. Actual values may vary according to dimensions, condition and applicable manufacturing standards.
