Rupal Metals is a well-respected name in the stainless steel industry, proudly based in Delhi, India. We specialize in manufacturing and supplying a diverse range of top-notch products, including the Stainless Steel 347 Hollow Bar. These bars are renowned for their impressive resistance to intergranular corrosion and their ability to withstand high temperatures, making them perfect for tough industrial applications. With state-of-the-art production facilities and a strong commitment to quality, Rupal Metals provides precision-engineered solutions that adhere to international standards. Our Stainless Steel 347 Hollow Bars are widely utilized in sectors like petrochemical, aerospace, power generation, and fabrication, showcasing our dedication to performance, durability, and customer satisfaction.
Stainless Steel 347 Hollow Bar is a niobium-stabilized austenitic stainless steel alloy that boasts remarkable high-temperature strength and corrosion resistance. Typically, it contains 17–20% chromium and 9–13% nickel, with niobium (columbium) added to prevent carbide precipitation. Additionally, it has trace amounts of manganese, silicon, and a maximum of 0.08% carbon. This alloy offers a tensile strength of around 515 MPa and a yield strength of about 205 MPa, along with good elongation properties. It maintains its mechanical integrity even at elevated temperatures, making it suitable for applications that involve thermal cycling, welding, and pressure containment.
| Standard | ASTM A276 / A479, ASME SA276 / A479 |
| Round Bar Size | 3mm~ 800mm |
| Square Bar Size | 4mm* 4mm ~100mm* 100mm |
| Flat Bar Size | 2mm ~ 100mm |
| Hex Bar Size | 2mm ~ 100mm |
| Angle Size | 3mm* 20mm* 20mm~ 12mm* 100mm* 100mm |
| Thickness | 50 mm to 6000 mm Long |
| Length | 1 To 6 Meters, Custom Cut Length |
| Form | Round, Square, Hex(A/F), Rectangle, Billet, Ingot, Forging Etc |
| Grade | C | Mn | Si | P | S | Cr | Co + Ta | Ni | Fe |
| SS 347 | 0.08 max | 2 max | 0.75 max | 0.045 max | 0.03 max | 17 – 20 | 10xC min 1.00 max | 9 – 13 | 62.74 |
| Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| 8.0 g/cm3 | 1454 °C (2650 °F) | Psi – 75000 , MPa – 515 | Psi – 30000 , MPa – 205 | 40 % |
| STANDARD | WERKSTOFF NR. | UNS | JIS | BS | GOST | AFNOR | EN |
| SS 347 | 1.4550 | S34700 | SUS 347 | – | 08Ch18N12B | – | X6CrNiNb18-10 |
| Stainless Steel 347 Hollow Bar Size | Chucked true to OD | Chucked true to ID | |||||||
| OD, mm | ID, mm | Max. OD, mm | Min. ID, mm | Max. OD, in. | Min. ID, in. | Max. OD, mm | Min. ID, mm | Max. OD, in. | Min. ID, in. |
| 32 | 20 | 31 | 21.9 | 1.220 | 0.862 | 30 | 21 | 1.185 | 0.827 |
| 32 | 16 | 31 | 18 | 1.220 | 0.709 | 30 | 17 | 1.181 | 0.669 |
| 36 | 25 | 35 | 26.9 | 1.378 | 1.059 | 34.1 | 26 | 1.343 | 1.024 |
| 36 | 20 | 35 | 22 | 1.378 | 0.866 | 34 | 21 | 1.339 | 0.827 |
| 36 | 16 | 35 | 18.1 | 1.378 | 0.713 | 33.9 | 17 | 1.335 | 0.669 |
| 40 | 28 | 39 | 29.9 | 1.535 | 1.177 | 38.1 | 29 | 1.500 | 1.142 |
| 40 | 25 | 39 | 27 | 1.535 | 1.063 | 38 | 26 | 1.496 | 1.024 |
| 40 | 20 | 39 | 22.1 | 1.535 | 0.870 | 37.9 | 21 | 1.492 | 0.827 |
| 45 | 32 | 44 | 33.9 | 1.732 | 1.335 | 43.1 | 33 | 1.697 | 1.299 |
| 45 | 28 | 44 | 30 | 1.732 | 1.181 | 43 | 29 | 1.693 | 1.142 |
| 45 | 20 | 44 | 22.2 | 1.732 | 0.874 | 42.8 | 21 | 1.685 | 0.827 |
| 50 | 36 | 49 | 38 | 1.929 | 1.496 | 48 | 37 | 1.890 | 1.457 |
| 50 | 32 | 49 | 34.1 | 1.929 | 1.343 | 47.9 | 33 | 1.886 | 1.299 |
| 50 | 25 | 49 | 27.2 | 1.929 | 1.071 | 47.8 | 26 | 1.882 | 1.024 |
| 56 | 40 | 55 | 42 | 2.165 | 1.654 | 54 | 41 | 2.126 | 1.614 |
| 56 | 36 | 55 | 38.1 | 2.165 | 1.500 | 53.9 | 37 | 2.122 | 1.457 |
| 56 | 28 | 55 | 30.3 | 2.165 | 1.193 | 53.7 | 29 | 2.114 | 1.142 |
| 63 | 50 | 62 | 51.9 | 2.441 | 2.043 | 61.1 | 51 | 2.406 | 2.008 |
| 63 | 45 | 62 | 47 | 2.441 | 1.850 | 61 | 46 | 2.402 | 1.811 |
| 63 | 40 | 62 | 42.2 | 2.441 | 1.661 | 60.8 | 41 | 2.394 | 1.614 |
| 63 | 36 | 62 | 38.3 | 2.441 | 1.508 | 60.7 | 37 | 2.390 | 1.457 |
| 63 | 32 | 62 | 34.4 | 2.441 | 1.354 | 60.6 | 33 | 2.386 | 1.299 |
| 71 | 56 | 69.9 | 58 | 2.752 | 2.283 | 68.9 | 57 | 2.713 | 2.244 |
| 71 | 45 | 69.9 | 47.3 | 2.752 | 1.862 | 68.6 | 46 | 2.701 | 1.811 |
| 71 | 40 | 69.9 | 42.4 | 2.752 | 1.669 | 68.5 | 41 | 2.697 | 1.614 |
| 71 | 36 | 69.9 | 38.5 | 2.752 | 1.516 | 68.4 | 37 | 2.693 | 1.457 |
| 75 | 60 | 73.8 | 62 | 2.906 | 2.441 | 72.8 | 61 | 2.866 | 2.402 |
| 75 | 50 | 73.8 | 52.2 | 2.906 | 2.055 | 72.6 | 51 | 2.858 | 2.008 |
| 75 | 40 | 73.8 | 42.5 | 2.906 | 1.673 | 72.3 | 41 | 2.846 | 1.614 |
| 80 | 63 | 78.8 | 65 | 3.102 | 2.559 | 77.8 | 64 | 3.063 | 2.520 |
| 80 | 50 | 78.8 | 52.4 | 3.102 | 2.053 | 77.4 | 51 | 3.047 | 2.008 |
| 80 | 45 | 78.8 | 47.5 | 3.102 | 1.870 | 77.3 | 46 | 3.043 | 1.811 |
| 80 | 40 | 78.8 | 42.6 | 3.102 | 1.677 | 77.2 | 41 | 3.039 | 1.614 |
| 85 | 67 | 83.7 | 69.1 | 3.295 | 2.720 | 82.6 | 68 | 3.252 | 2.677 |
| 85 | 55 | 83.7 | 57.4 | 3.295 | 2.260 | 82.3 | 56.0 | 3.240 | 2.205 |
| 85 | 45 | 83.7 | 47.6 | 3.295 | 1.874 | 82.1 | 46.0 | 3.232 | 1.811 |
| 90 | 71 | 88.6 | 73.1 | 3.488 | 2.878 | 87.6 | 72.1 | 3.449 | 2.839 |
| 90 | 63 | 88.6 | 65.3 | 3.488 | 2.571 | 87.3 | 64.0 | 3.437 | 2.520 |
| 90 | 56 | 88.6 | 58.5 | 3.488 | 2.303 | 87.1 | 57.0 | 3.429 | 2.244 |
| 90 | 50 | 88.6 | 52.6 | 3.488 | 2.071 | 87.0 | 51.0 | 3.425 | 2.008 |
| 95 | 75 | 93.5 | 77.3 | 3.681 | 3.041 | 92.4 | 76.2 | 3.641 | 2.997 |
| 95 | 67 | 93.5 | 69.3 | 3.681 | 2.728 | 92.2 | 68.0 | 3.630 | 2.677 |
| 95 | 50 | 93.5 | 52.7 | 3.681 | 2.075 | 91.8 | 51.0 | 3.614 | 2.008 |
| 100 | 80 | 98.5 | 82.3 | 3.878 | 3.240 | 97.4 | 81.2 | 3.835 | 3.197 |
| 100 | 71 | 98.5 | 73.4 | 3.878 | 2.890 | 97.2 | 72.1 | 3.827 | 2.839 |
| 100 | 63 | 98.5 | 65.5 | 3.878 | 2.579 | 97.0 | 64.0 | 3.819 | 2.520 |
| 100 | 56 | 98.5 | 58.7 | 3.878 | 2.311 | 96.8 | 57.0 | 3.811 | 2.244 |
| 106 | 80 | 104.4 | 82.5 | 4.110 | 3.248 | 103.1 | 81.2 | 4.059 | 3.197 |
| 106 | 71 | 104.4 | 73.5 | 4.110 | 2.894 | 103.0 | 72.1 | 4.055 | 2.839 |
| 106 | 63 | 104.4 | 65.7 | 4.110 | 2.587 | 102.7 | 64.0 | 4.043 | 2.520 |
| 106 | 56 | 104.4 | 58.9 | 4.110 | 2.319 | 102.5 | 57.0 | 4.035 | 2.244 |
| 112 | 90 | 110.3 | 92.5 | 4.343 | 3.642 | 109.2 | 91.4 | 4.299 | 3.598 |
| 112 | 80 | 110.3 | 82.6 | 4.343 | 3.252 | 108.9 | 81.2 | 4.287 | 3.197 |
| 112 | 71 | 110.3 | 73.7 | 4.343 | 2.902 | 108.7 | 72.1 | 4.280 | 2.839 |
| 112 | 63 | 110.3 | 65.8 | 4.343 | 2.591 | 108.5 | 64.0 | 4.272 | 2.520 |
| 118 | 90 | 116.2 | 92.7 | 4.575 | 3.650 | 114.9 | 91.4 | 4.524 | 3.598 |
| 118 | 80 | 116.2 | 82.8 | 4.575 | 3.260 | 114.6 | 81.2 | 4.512 | 3.197 |
| 118 | 71 | 116.2 | 73.8 | 4.575 | 2.906 | 114.5 | 72.1 | 4.508 | 2.839 |
| 118 | 63 | 116.2 | 66.0 | 4.575 | 2.598 | 114.2 | 64.0 | 4.496 | 2.520 |
| 125 | 100 | 123.1 | 102.7 | 4.846 | 4.043 | 121.9 | 101.5 | 4.799 | 3.996 |
| 125 | 90 | 123.1 | 92.8 | 4.846 | 3.654 | 121.7 | 91.4 | 4.791 | 3.598 |
| 125 | 80 | 123.1 | 82.9 | 4.846 | 3.264 | 121.4 | 81.2 | 4.780 | 3.197 |
| 125 | 71 | 123.1 | 74.0 | 4.846 | 2.913 | 121.3 | 72.1 | 4.772 | 2.839 |
| 132 | 106 | 130.0 | 108.8 | 5.118 | 4.283 | 128.8 | 107.6 | 5.071 | 4.236 |
| 132 | 90 | 130.0 | 93.0 | 5.118 | 3.661 | 128.4 | 91.4 | 5.055 | 3.598 |
| 132 | 80 | 130.0 | 83.1 | 5.118 | 3.272 | 128.1 | 81.2 | 5.043 | 3.197 |
| 132 | 71 | 130.0 | 74.2 | 5.118 | 2.921 | 121.2 | 72.1 | 5.035 | 2.839 |
| 140 | 112 | 137.9 | 115 | 5.429 | 4.528 | 136.6 | 113.7 | 5.378 | 4.476 |
| 140 | 100 | 137.9 | 103.1 | 5.429 | 4.059 | 136.3 | 101.5 | 5.366 | 3.996 |
| 140 | 90 | 137.9 | 93.2 | 5.429 | 3.669 | 136.1 | 91.4 | 5.358 | 3.598 |
| 140 | 80 | 137.9 | 83.3 | 5.429 | 3.280 | 135.8 | 81.2 | 5.346 | 3.197 |
| 150 | 125 | 147.7 | 128.1 | 5.815 | 5.043 | 146.5 | 126.9 | 5.768 | 4.996 |
| 150 | 106 | 147.7 | 109.3 | 5.815 | 4.303 | 146 | 107.6 | 5.748 | 4.236 |
| 150 | 95 | 147.7 | 98.4 | 5.815 | 3.874 | 145.7 | 96.4 | 5.736 | 3.795 |
| 150 | 80 | 147.7 | 83.6 | 5.815 | 3.291 | 145.3 | 81.2 | 5.720 | 3.197 |
| 160 | 132 | 157.6 | 135.3 | 6.205 | 5.327 | 156.3 | 134 | 6.154 | 5.276 |
| 160 | 122 | 157.6 | 125.4 | 6.205 | 4.937 | 156 | 123.8 | 6.142 | 4.874 |
| 160 | 112 | 157.6 | 115.5 | 6.205 | 4.547 | 155.8 | 113.7 | 6.134 | 4.476 |
| 160 | 90 | 157.6 | 94.0 | 6.205 | 3.701 | 155.2 | 91.4 | 6.110 | 3.598 |
| 170 | 140 | 167.4 | 143.5 | 6.591 | 5.650 | 166 | 142.1 | 6.535 | 5.594 |
| 170 | 130 | 167.4 | 133.6 | 6.591 | 5.260 | 165.8 | 132 | 6.528 | 5.197 |
| 170 | 128 | 167.4 | 131.6 | 6.591 | 5.181 | 165.7 | 130 | 6.524 | 5.118 |
The primary advantages of using SS 347 hollow bars in high-temperature applications include excellent resistance to intergranular corrosion, enhanced heat resistance, and stability in extreme conditions. These properties make it ideal for use in heat exchangers, reactors, and furnace components.
The addition of columbium (niobium) in SS 347 improves its resistance to intergranular corrosion, particularly after welding. It stabilizes the steel's microstructure, preventing carbide precipitation at grain boundaries, and enhances overall corrosion resistance in aggressive, high-temperature environments.
SS 347 hollow bars are commonly used in the chemical processing, aerospace, power generation, and petrochemical industries. Typical applications include heat exchangers, reactor vessels, piping systems, and furnace components, where resistance to high temperatures and corrosion is essential.
Stainless Steel 347 Hollow Bar finds its place in various applications that demand high-temperature resistance and excellent weldability. It’s perfect for heat exchangers, boiler tubes, pressure vessels, furnace components, and exhaust systems. Thanks to niobium stabilization, it effectively prevents intergranular corrosion after welding, making it a top choice for welded constructions in chemical and power plants. Its hollow design not only provides strength but also reduces weight, making it ideal for structural supports and process piping.






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