In August 2025, a long-standing customer in Singapore sent us an inquiry for 347H stainless steel pipe. We rigorously verified the material quality according to the ASTM A312 standard and conducted spectral analysis and mechanical testing to ensure the 347H stainless steel high-temperature resistance and intergranular corrosion resistance met the customer’s requirements. Subsequently, our production department worked overtime to significantly increase production efficiency while ensuring quality. The finished pipes underwent a series of inspections and surface treatments and were accompanied by a complete MTC material certificate. Upon receipt, the customer expressed high praise for our product quality and delivery speed.
This not only solidified our long-standing partnership with our Singaporean customer but also further demonstrated our expertise and reliable service in the supply of high-performance stainless steel pipe.
Inspection Video
347H Stainless Steel Pipe MTC
ASTM A312 Stainless Steel Pipe Specification
| Processing Method | Seamless and Welded |
| Size Range | 1/8” – 30” / DN6 – 750 |
| Thickness Schedule | SCH 10S- SCH 160, XXS |
| Length | 6m or 12 m or Random |
| Standard | ASME B36.19 |
| Surface Treatment | Polish , Mirror , Epoxy Powder FBE, 2PE, 3PE Coating |
| Material Grade | ASTM A312 TP304/304L/304H, 316/316L, 310S, 317, 347, 904L, S32205, S31803, 32750, 32760, S32550 |
Equivalent materials
| China | American | Japanese | German |
| 06Cr18Ni11Nb | Grade 347 | SUS 347 | X6CrNiNb18-10, 1.4550 |
| 07Cr18Ni11Nb | Grade 347H | / | X7CrNiNb18-10, 1.4912 |
347/347H Chemical Composition
| Material | C | Mn | Si | Cr | Ni | P | S | Nb |
| 347 | ≤0.08 | ≤2.00 | ≤0.75 | 17.0~19.0 | 9.0~13.0 | ≤0.045 | ≤0.03 | 10C~1.00 |
| 347H | 0.04~0.10 | ≤2.00 | ≤0.75 | 17.0~19.0 | 9.0~13.0 | ≤0.045 | ≤0.03 | 8C~1.00 |
347/347H Physical Properties
| Yield Strength, 0.2% Offset MPa | Ultimate Tensile Strength, MPa | Elongation in 2 in. or 51 mm | Hardness, Max., Brinell |
| 205 | 515 | 35 | 217 |
Stainless Steel Pipe Dimension
| Stainless Steel Pipe (ASME B 36.19M) | ||||||||||
| Nominal Size | OD | Sch5s | Sch10s | Sch40s | Sch80s | |||||
| DN | NPS | 0 | T | kg/m | T | kg/m | T | kg/m | T | kg/m |
| 6 | 1/8 | 10.3 | 1.24 | 0.28 | 1.73 | 0.37 | 2.41 | 0.47 | ||
| 8 | 1/4 | 13.7 | 1.65 | 0.49 | 2.24 | 0.63 | 3.02 | 0.8 | ||
| 10 | 3/8 | 17.1 | 1.65 | 0.63 | 2.31 | 0.84 | 3.2 | 1.1 | ||
| 15 | 1/2 | 21.3 | 1.65 | 0.82 | 2.11 | 1 | 2.77 | 1.27 | 3.73 | 1.62 |
| 20 | 3/4 | 26.7 | 1.65 | 1.04 | 2.11 | 1.28 | 2.87 | 1.69 | 3.91 | 2.2 |
| 25 | 1 | 33.4 | 1.65 | 1.33 | 2.77 | 2.09 | 3.38 | 2.5 | 4.55 | 3.24 |
| 32 | 1 1/4 | 42.2 | 1.65 | 1.68 | 2.77 | 2.7 | 3.56 | 3.39 | 4.85 | 4.47 |
| 40 | 1 1/2 | 48.3 | 1.65 | 1.95 | 2.77 | 3.11 | 3.68 | 4.05 | 5.08 | 5.41 |
| 50 | 2 | 60.3 | 1.65 | 2.44 | 2.77 | 3.93 | 3.91 | 5.44 | 5.54 | 7.48 |
| 65 | 2 1/2 | 73.0 | 2.11 | 3.77 | 3.05 | 5.26 | 5.16 | 8.63 | 7.01 | 11.41 |
| 80 | 3 | 88.9 | 2.11 | 4.6 | 3.05 | 6.45 | 5.49 | 11.29 | 7.62 | 15.27 |
| 90 | 31/2 | 101.6 | 2.11 | 5.29 | 3.05 | 7.4 | 5.74 | 13.57 | 8.08 | 18.63 |
| 100 | 4 | 114.3 | 2.11 | 5.96 | 3.05 | 8.36 | 6.02 | 16.07 | 8.56 | 22.32 |
| 125 | 5 | 141.3 | 2.77 | 9.67 | 3.4 | 11.57 | 6.55 | 21.77 | 9.53 | 30.97 |
| 150 | 6 | 168.3 | 2.77 | 11.55 | 3.4 | 13.48 | 7.11 | 28.26 | 10.97 | 42.56 |
| 200 | 8 | 219.1 | 2.77 | 15.09 | 3.76 | 19.96 | 8.18 | 42.55 | 12.7 | 64.64 |
| 250 | 10 | 273.1 | 3.4 | 23.08 | 4.19 | 27.78 | 9.27 | 60.31 | 12.7 | 96.01 |
| 300 | 12 | 323.9 | 3.96 | 31.89 | 4.57 | 36 | 9.53 | 73.88 | 12.7 | 132.08 |
| 350 | 14 | 355.6 | 3.96 | 35.06 | 4.78 | 41.3 | ||||
| 400 | 16 | 406.4 | 4.19 | 42.41 | 4.78 | 47.29 | ||||
| 450 | 18 | 457.2 | 4.19 | 47.77 | 4.78 | 53.26 | ||||
Manufacturing Process
ASTM A312 covers two primary manufacturing processes:
Seamless steel : Made from billets through piercing and cold drawing/cold rolling, the pipe body has no welds and is suitable for applications requiring high pressure, high temperature, or high strength.
Welded : Made from coiled steel plate or strip and then welded, it is relatively low-cost and suitable for applications with less stringent pressure requirements.
Applications
Chemical Industry: Heat exchangers, chemical storage tanks, and piping systems
Oil and Gas: Pipelines transporting chloride-containing or corrosive media
Marine Engineering: Desalination plants, offshore platforms
Food and Pharmaceuticals: Pharmaceutical equipment, food processing piping
Energy: High-temperature boiler tubes, heat exchangers