DIN 1.4762 Stainless Steel Pipes for Heat Exchangers
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GNEE, as a professional exporter of stainless steel heat exchanger tubes, achieves an annual export volume of over 3,000 tons. We supply EN 10216-2 1.4762 stainless steel EFW pipes, whose weld seam treatment process effectively eliminates oxidation, stress cracking, and corrosion risks, making them suitable for high-temperature heat exchangers, boiler systems, and petrochemical equipment.
Our DIN 1.4762 stainless steel heat exchanger tubes are manufactured using a precision electric fusion welding (EFW) process, with strict control of heat input within 0.8–2.2 kJ/mm and interpass temperature below 150°C, effectively preventing σ-phase precipitation and ensuring high-temperature structural stability.
The weld reinforcement height is controlled between 0.2–0.5 mm, with weld width deviation within ±0.1 mm, and a full penetration rate as high as 99.8%. Post-weld treatment includes online solution annealing at 1120–1180°C followed by argon-protected cooling, acid pickling and passivation to restore the Cr₂O₃ passive layer, and internal weld polishing to achieve a surface roughness (Ra) of ≤0.8 μm.
Each weld undergoes 100% eddy current testing (ET) and hydrostatic testing at 20–28 MPa, ensuring zero leakage, with a defect rate of less than 0.01%.
ASTM A268 TP446 heat exchanger tube specification
| Product Name | DIN1.4762 Stainless Seamless Steel Tubes |
| Thickness |
0.5 mm - 68 mm SCH10, SCH20, SCH30, STD, SCH40, SCH60, SCH80, SCH100,SCH120, SCH160, XS, XXS |
| Outside Diameter | 4 mm -720 mm |
| Length | As requirement |
| Finish | Acid Pickling,Polished,Unpolished,Mirror,HL,180 Grit,400 Grit,600 Grit |
| Technical | Hot rolled , cold drawing , precision rolling |
| Certification | ISO 9001:2008,MTC,PMI,CO,SGS |
TP446 heat exchanger tube Composition
| Grade | C | Mn | Si | P | S | Cr | Ni | N | |
| 446 | min. | – | – | – | – | – | 23.0 | – | 0.10 |
| max. | 0.20 | 1.5 | 0.75 | 0.040 | 0.030 | 30.0 | 0.50 | 0.25 | |
ferritic stainless steel 446 tube Mechanical properties
| Grade | Tensile Strength (MPa) min | Yield Strength 0.2% Proof (MPa) min | Elongation (% in 50mm) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| 446 | 485 | 275 | 20 | 92 | 201 |
UNS S44600 Pipe Thermal Properties
| Properties | Value |
|---|---|
| Thermal Conductivity | 21.6 W/mK |
| Thermal Expansion Co-efficient | 10.4 µm/m°C |
1.4762 Stainless Steel Tubes Tolerances
| Stainless Steel 1.4762 Tube OD | Stainless Steel 1.4762 Tube Tolerance |
| 4mm to 35mm | +/- 0.08mm |
| 35mm to 38mm | +/- 0.15mm |
| 38mm to 60mm | +/- 0.20mm |
| 60mm and above | +/- 0.25mm |
Schedule Chart of DIN 1.4762 Welded Pipe
| Pipe Size | O.D. inches | Schedule | |||||||
|---|---|---|---|---|---|---|---|---|---|
| XXH | 160 | XH | 80 | STD | 40 | 10 | 5 | ||
| 1/4 | 0.540 | .5351 | .5351 | .4248 | .4248 | .3297 | .2570 | ||
| 1/8 | 0.405 | .3145 | .3145 | .2447 | .2447 | .1863 | .1383 | ||
| 3/8 | 0.675 | .7388 | .7388 | .5676 | .5676 | .4235 | .3276 | ||
| 3/4 | 1.050 | 2.441 | 1.937 | 1.474 | 1.474 | 1.131 | 1.131 | .8572 | .6838 |
| 1/2 | 0.840 | 1.714 | 1.304 | 1.088 | 1.088 | .8510 | .8510 | .6710 | .5380 |
| 1 | 1.315 | 5.214 | 2.844 | 2.172 | 2.172 | 1.679 | 1.679 | 1.404 | .8678 |
| 1-1/2 | 1.900 | 6.408 | 4.859 | 3.631 | 3.631 | 2.718 | 2.718 | 2.085 | 1.604 |
| 1-1/4 | 1.660 | 5.214 | 3.765 | 2.997 | 2.997 | 2.273 | 2.273 | 1.806 | 1.107 |
| 2 | 2.375 | 9.029 | 7.444 | 5.022 | 5.022 | 3.653 | 3.653 | 2.638 | 1.604 |
| 3 | 3.500 | 18.58 | 14.32 | 10.25 | 10.25 | 7.576 | 7.576 | 4.332 | 3.029 |
| 2-1/2 | 2.875 | 13.69 | 10.01 | 7.661 | 7.661 | 5.793 | 5.793 | 3.531 | 2.475 |
| 3-1/2 | 4.000 | 22.85 | 12.50 | 14.98 | 9.109 | 9.109 | 4.973 | 3.472 | |
Weight of Stainless Steel 446 Pipe
| Nominal size [inches] | Outside diameter [inches] | Outside diameter [mm] | Wall thickness [inches] | Wall thickness [mm] | Weight [lb/ft] | Weight [kg/m] |
| 8 | 8,625 | 219,1 | 0,594 | 15,09 | 50,95 | 75,92 |
| 10 | 10,750 | 273,0 | 0,719 | 18,26 | 77,03 | 114,75 |
| 12 | 12,750 | 323,8 | 0,844 | 21,44 | 107,32 | 159,91 |
| 14 | 14,000 | 355,6 | 0,938 | 23,83 | 130,85 | 194,96 |
| 16 | 16,000 | 406,4 | 1,031 | 26,19 | 164,82 | 245,56 |
| 18 | 18,000 | 457,0 | 1,156 | 29,36 | 207,96 | 309,62 |
| 20 | 20,000 | 508,0 | 1,281 | 32,54 | 256,10 | 381,53 |
| 22 | 22,000 | 559,0 | 1,375 | 34,93 | 302,88 | 451,42 |
| 24 | 24,000 | 610,0 | 1,531 | 38,89 | 367,39 | 547,71 |
HS Code for ASTM A268 TP446 Stainless Steel Heat Exchanger Tube
| Product Description | HS Code (6-digit) |
|---|---|
| Seamless stainless steel tubes (heat exchanger tubes) | 7304.41 |
| Other seamless stainless steel tubes | 7304.49 |
What is the maximum working temperature of TP446 tubes?
TP446 stainless steel tubing is specifically designed for high-temperature applications and is typically suitable for environments reaching up to 1,150°C (2,100°F). Thanks to its high chromium content-ranging from 26% to 30%-this material exhibits exceptional resistance to scaling. Although it maintains excellent oxidation resistance at temperatures up to 1,000°C (1,832°F), its high-temperature strength is relatively low.
buy TP446 heat exchanger tubes
1. Our stainless steel tubing undergoes bright annealing, internal weld bead removal, and precision polishing. The surface roughness of the tubing can be controlled to within 0.3μm.
2. All raw materials are sourced from renowned steel mills, including TISCO, Baosteel, and Zhangpu.
3. Our tubing has obtained certifications such as AD 2000-W0, PED 2014/68/EU, and ISO 9001:2015.
4. Throughout the entire manufacturing process, we ensure comprehensive material traceability.
We are equipped with non-destructive testing (NDT) capabilities, such as online eddy current testing, as well as hydrostatic or pneumatic leak testing.
Flaring & Flattening Tests: To ensure ductility for tube-to-tubesheet expansion.
Hardness Testing: Guaranteed max 95 HRB (207 HBW) per standard.
Non-Destructive Testing (NDT): 100% Eddy Current or Hydrostatic testing.
Intergranular Corrosion (IGC) Test: Available upon request to verify material purity.
Plastic Sleeving: Each TP446 tube is individually enclosed in a protective plastic sleeve or PE film.
End Caps: Both ends of the tubes are fitted with high-quality plastic or LDPE end caps.
Hexagonal Bundling: The tubes are typically arranged in hexagonal bundles to ensure maximum structural stability.
Reinforced Plywood Crates (Recommended): For international maritime shipping, we utilize plywood crates that comply with ISPM-15 standards (fumigation-free). These crates provide robust external protection, effectively safeguarding the contents against stacking pressure and lateral impact.
