Stainless Steel 347/347H Square Bars are high-temperature resistant austenitic stainless steel products designed for demanding industrial, mechanical, and structural engineering applications. American Metallix Steel Co. manufactures precision-engineered SS 347 and 347H square bars to meet the performance expectations of power plants, refineries, petrochemical facilities, and heavy fabrication industries.These square bars are particularly valued in environments where components are exposed to elevated temperatures and cyclic heating. Their niobium stabilization enhances resistance to intergranular corrosion, making them suitable for welded structures and pressure equipment. Stainless Steel 347/347H Square Bars deliver reliable strength, dimensional accuracy, and durability in both high-pressure and high-heat operating conditions.
Stainless Steel 347 is a niobium-stabilized austenitic chromium-nickel stainless steel. The addition of niobium prevents chromium carbide precipitation during welding and prolonged exposure to elevated temperatures. Grade 347H is the high-carbon version, developed specifically for improved creep resistance and higher strength at elevated temperatures. The chemical composition typically includes chromium for corrosion resistance, nickel for toughness and ductility, and niobium for stabilization. The austenitic microstructure provides excellent toughness even at low temperatures, while maintaining strength at high temperatures. Stainless Steel 347/347H Square Bars exhibit good tensile and yield strength, making them suitable for load-bearing and structural applications in harsh industrial environments. These square bars perform reliably in oxidation conditions up to elevated temperatures commonly found in boilers, heat exchangers, and furnace components. Their resistance to intergranular corrosion after welding makes them ideal for fabricated assemblies, pipelines, and structural supports exposed to thermal stress.
One of the key advantages of Stainless Steel 347/347H Square Bars is their excellent resistance to intergranular corrosion. The niobium stabilization ensures structural integrity even after welding, which is critical in pressure vessels, piping systems, and structural frameworks used in chemical processing plants. High-temperature strength is another major benefit. Grade 347H offers enhanced creep resistance, allowing it to maintain mechanical properties under continuous high-temperature exposure. This makes it suitable for power generation equipment, exhaust systems, and heat treatment components. Durability and long service life contribute to overall cost efficiency. Stainless Steel 347/347H Square Bars reduce maintenance frequency and downtime in industrial plants. They are also machinable and formable, allowing engineers to fabricate complex components while maintaining tight dimensional tolerances. Their corrosion resistance in acidic and oxidizing environments ensures dependable performance in aggressive processing conditions.
In high-temperature process industries, Stainless Steel 347/347H Square Bars Manufacturers supply materials used in boiler tubes, superheater supports, and furnace parts that require stability under thermal cycling. The high creep strength of 347H grade ensures safety and reliability in continuous heat exposure environments. Within the petrochemical and refinery sectors, Stainless Steel 347/347H Square Bars Suppliers provide square bar stock for fabrication of reactor components, heat exchangers, and pressure retaining parts. The resistance to intergranular corrosion ensures welded assemblies remain durable during prolonged service.
For heavy fabrication and structural engineering projects, Stainless Steel 347/347H Square Bars Stockists maintain ready inventory for manufacturing frames, support structures, and industrial platforms. These square bars offer consistent geometry and mechanical strength for structural stability in demanding environments. In global infrastructure and power generation markets, Stainless Steel 347/347H Square Bars Exporters deliver certified materials for use in thermal power plants, offshore structures, and chemical processing facilities. Strict adherence to international standards ensures safe transport and dependable performance across diverse applications.
Stainless Steel 347/347H Square Bars are commonly manufactured in accordance with ASTM A276 and ASTM A479 specifications, covering stainless steel bars and shapes for general engineering and pressure vessel applications. For high-temperature and boiler service, ASME SA276 and ASME SA479 are applicable standards. These specifications define chemical composition limits, mechanical properties, heat treatment requirements, and dimensional tolerances. Compliance with these ASTM and ASME standards ensures that Stainless Steel 347/347H Square Bars are suitable for use in pressure equipment, heat exchangers, piping systems, and structural components operating in elevated temperature environments.
Steel products including square bars, round bars, pipes, tubes, plates, sheets, and coils are classified based on chemical composition, mechanical properties, and intended application under globally recognized standards such as ASTM, ASME, EN, DIN, JIS, and ISO. ASTM and ASME standards are widely used for industrial fabrication and pressure equipment in North America and other global markets. EN and DIN standards regulate European material specifications, while JIS governs Japanese industrial grades. ISO standards provide international alignment for quality systems and testing procedures. Stainless Steel 347 and 347H grades are identified according to their alloy content and high-temperature performance characteristics, enabling engineers and procurement specialists to select appropriate materials for structural engineering, chemical processing, and power plant applications.
American Metallix Steel Co. is one of the leading manufacturer and supplier of 347 Stainless Steel ASTM A276 Round Bar, SS 347 ASME SA 276 Polished Bar, 347/347H SS Black Bar, 347/347H Stainless Steel Rods, ASTM A276 SUS 347 Round Bar, ASME SA 276 347H Bar, Round Bar, Hex Bar at the best price in India.
Request Latest Price & Stock AvailabilityStainless Steel Square Bars are available in multiple grades, sizes, finishes and production methods to meet industrial, structural, marine and engineering requirements.
| Specification | Details |
|---|---|
| Specifications | ASTM / ASME SA A582, A276, A564, ASTM A484, ASTM A484M |
| Range | 3.17 MM TO 350 MM |
| Diameter | 25 mm to 152 mm |
| Tolerance | h8, h9 (DIN 671), h10, h11, ASTM A484, DIN 1013 |
| Finish | Bright, Polish & Black |
| Form | Square Bars |
| Condition | Cold Drawn & Polished, Cold Drawn, Centreless Ground & Polished |
| Other Services |
|
Our Stainless Steel Square Bar conforms to Standard ISO 15156 / NACE MR0175.
The chemical composition of Stainless Steel 347/347H Square Bars provides excellent corrosion resistance, high-temperature strength, and oxidation resistance for demanding industrial applications.
| Grade | C | Mn | Si | P | S | Cr | Cb + Ta | Ni | Fe |
|---|---|---|---|---|---|---|---|---|---|
| SS 347 | 0.08 max | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 17.00 – 20.00 | 10 × C min, 1.00 max | 9.00 – 13.00 | Balance (62.74) |
| SS 347H | 0.04 – 0.10 | 2.00 max | 0.75 max | 0.045 max | 0.030 max | 17.00 – 20.00 | 8 × C min, 1.00 max | 9.00 – 13.00 | Balance (62.74) |
The above chemical composition represents the standard requirements for Stainless Steel 347 and 347H Square Bars in accordance with ASTM and ASME specifications. All values are expressed as weight percentages unless otherwise specified.
The mechanical properties of Stainless Steel 347/347H Square Bars provide excellent strength, ductility and heat resistance, making them suitable for high-temperature and pressure applications.
| Density | Melting Point | Tensile Strength | Yield Strength (0.2% Offset) | Elongation |
|---|---|---|---|---|
| 8.0 g/cm³ | 1454°C (2650°F) | Psi – 75,000 MPa – 515 |
Psi – 30,000 MPa – 205 |
40% |
The above values represent the standard mechanical properties of Stainless Steel 347 and 347H Square Bars. Values may vary slightly depending on manufacturing process, heat treatment and applicable ASTM/ASME specifications.
