ASTM A268 TP444 Stainless Steel Heat Exchanger Tubes
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If you are looking for stainless steel heat exchanger tubing that combines excellent resistance to chloride corrosion, high thermal conductivity, and a long service life, ASTM A268 TP444 stainless steel tubing is undoubtedly an ideal choice. As a ferritic stainless steel, it is widely used in applications such as power plants, chemical processing, water treatment, automotive exhaust systems, and industrial heat exchangers.
What is ASTM A268 TP444 Stainless Steel Heat Exchanger Tube?
TP444 stainless steel (UNS S44400) is a molybdenum-bearing ferritic stainless steel with a chromium content of approximately 18%–20% and a molybdenum content of approximately 1.75%–2.50%. Its corrosion resistance rivals that of certain 300-series stainless steels, while offering superior resistance to chloride stress corrosion cracking.
With 18 years of experience exporting stainless steel heat exchanger tubes, GNEE supplies products compliant with ASTM, ASME, EN, and JIS standards. Supporting trade terms such as FOB, CIF, and DDP, we provide stable and reliable stainless steel tubing solutions to global manufacturers of boilers, energy systems, chemical processing equipment, and heat exchangers.
GNEE offers a comprehensive range of products, including ASTM A268 TP444 seamless tubes, welded tubes, U-bend tubes, straight tubes, coiled tubing, and custom-engineered heat exchanger tubes fabricated precisely to customer drawings. TP444 is an ultra-low carbon, high-chromium ferritic stainless steel. Through solution annealing, residual processing stresses are fully relieved, ensuring a smooth, uniform surface finish free of scale, cracks, or visible scratches. This premium quality meets heat exchanger manufacturers' stringent demands for optimal heat transfer efficiency and exceptional cleanliness.
In terms of dimensional precision and tolerance control, GNEE's ASTM A268 TP444 Stainless Steel Heat Exchanger Tubes generally cover an outer diameter (OD) range of 6 mm to 168.3 mm and a wall thickness (WT) range of 0.5 mm to 12 mm. We strictly control OD and WT tolerances based on individual equipment designs. Available delivery conditions include Bright Annealed (BA) and Annealed & Pickled (AP) finishes.
Regarding corrosion resistance, TP444 stainless steel tubing delivers significantly superior performance against pitting and crevice corrosion in chloride environments compared to standard ferritic grades like TP409 and TP439. With a PREN (Pitting Resistance Equivalent Number) of approximately 23–26, which is on par with certain TP316L materials, TP444 is highly suitable for seawater heat exchangers, condensing systems, chemical processing, food handling, and a wide array of industrial heat transfer applications.
ASTM A268 TP444 Stainless Steel Equivalent Grades
| Standard | Grade |
|---|---|
| ASTM | TP444 |
| UNS | S44400 |
| EN | 1.4521 |
| JIS | SUS444 |
| GB/T | 022Cr19Mo2 |
Chemical Composition of ASTM A268 TP444 Stainless Steel pipe
| Element | C | Mn | P | S | Si | Cr | Ni | Mo | N | Ti + Cb (Nb) |
|---|---|---|---|---|---|---|---|---|---|---|
| Composition (wt. %) | 0.025 max | 1.00 max | 0.040 max | 0.030 max | 1.00 max | 17.5 – 19.5 | 1.00 max | 1.75 – 2.50 | 0.035 max | 0.20 + 4(C + N) min; 0.80 max |
ASTM A268 TP444 pipe Mechanical Properties
| Property | Value (Metric) | Value (Imperial) |
| Tensile Strength, min. | 415 MPa | 60 ksi |
| Yield Strength (0.2% Offset), min. | 275 MPa | 40 ksi |
| Elongation in 2 in. (50mm), min. | 20% | 20% |
| Hardness (Rockwell B), max. | 90 HRB | 90 HRB |
| Hardness (Brinell), max. | 190 HBW | 190 HBW |
ASTM A268 pipe Dimensional Tolerances
Standard tolerances for Outside Diameter (OD) and Wall Thickness (WT).
| Outside Diameter (OD) Range | OD Tolerance | Wall Thickness (WT) Tolerance |
| < 1/2" (12.7 mm) | ± 0.005" (0.13 mm) | ± 15% |
| 1/2" to 1-1/2" (12.7-38.1 mm) | ± 0.005" (0.13 mm) | ± 10% |
| > 1-1/2" to 3-1/2" (38.1-88.9 mm) | ± 0.010" (0.25 mm) | ± 10% |
| Standard Length Tolerance | + 1/8" (3 mm), -0 |
ASTM A268 TP444 Stainless Steel round Tubes Applications
Heat Exchangers: Shell and tube exchangers in water heating systems.
Power Generation:Condenser tubes
Solar Collectors: Absorber tubes and hot water tanks.
Automotive: Exhaust systems and catalytic converter components.
Water Treatment: Desalination and potable water piping.
If you need help, please tell me:
What outer diameter and wall thickness do you need?
Are you looking for seamless or welded tubes?
What is the application or industry?
HS Codes for ASTM A268 TP444 Tubes
| Product Category | HS Code (General) |
| ASTM A268 TP444 Seamless Tubes | 7304.41 |
| ASTM A268 TP444 Welded Tubes | 7306.40 |
| ASTM A268 TP444 U-Bent Tubes | 7304.41 / 7306.40 |
ASTM A268 TP444 Tube Price List
| Product Form | Specification (OD x WT) | Estimated Price (USD/MT) | Processing Notes |
| Welded Tube (Standard) |
OD: 19.05 - 38.1 mm WT: 1.0 - 2.5 mm |
$3,200 – $3,800 | Bright Annealed, Eddy Current Tested. |
| Seamless Tube |
OD: 12.7 - 50.8 mm WT: 1.5 - 4.0 mm |
$4,500 – $5,500 | Cold Drawn, Heat Treated, Pickled. |
| U-Bent Tubes | Per Client Drawing | $3,800 – $4,800 | Includes bending and stress-relief annealing on the bend. |
If you have project requirements for TP444 stainless steel heat exchanger tubes, we welcome your orders. GNEE maintains a large inventory of popular products for you to choose from. Please contact our factory today; we offer competitive prices and excellent service.
Technical Requirements & Testing
| Test Category | Description |
| Heat Treatment | Annealing at 1450°F (790°C) minimum, followed by rapid cooling. |
| Flaring Test | No cracks or flaws when flared according to ASTM A1016. |
| Flange Test | Mandatory for certain diameters to ensure ductility. |
| Hardness Test | Performed on a specimen from each lot. |
| Hydrostatic / Eddy Current | 100% Non-Destructive Testing (NDT) required for pressure integrity. |
| Intergranular Corrosion | Must pass ASTM A763 Practice W or Z. |
GNEE provides an EN 10204 3.1 Material Test Certificate (MTC) for every batch of ASTM A268 TP444 heat exchanger tubes, ensuring traceability of chemical composition, heat numbers, mechanical properties, and compliance with standard requirements; this helps purchasers verify material authenticity and mitigate the risk of equipment failure caused by non-conforming materials.
High-quality sea freight packaging
| Packaging Type | Description |
|---|---|
| Wooden Crate (Standard) | Export-grade fumigated wooden crates or plywood boxes are used to arrange and secure tubes neatly. Internal supports prevent movement and damage during transportation. |
| Hexagonal Bundling | Tubes are bundled into a hexagonal shape using steel straps or nylon bands, then covered with woven fabric, plastic film, or waterproof material. |
| U-Bent Tube Packaging | Specially designed wooden frames or wooden boxes are used to fix and protect the U-bent section of heat exchanger tubes. |
FAQ
Q: What are the main advantages of TP444 over 316L in heat exchanger applications?
A: The most significant advantage is its resistance to stress corrosion cracking (SCC).
TP444 typically has a PREN (Pitting Resistance Equivalent Number) of 24–25 and is virtually immune to stress corrosion cracking in chloride-rich environments. In contrast, 316L typically has a PREN of 23–24 and is highly susceptible to stress corrosion cracking in the presence of chlorides at temperatures above 60°C.
Q: Is TP444 stainless steel magnetic?
A: Yes. TP444 is a ferritic stainless steel with a body-centered cubic (BCC) crystal structure. Unlike 304 or 316, TP444 is strongly magnetic.
Q: What is the maximum service temperature for TP444?
A: For pressure-bearing components such as heat exchanger tubes, the recommended continuous service temperature is generally limited to 315°C (600°F).
Q: Why is TP444 commonly used in solar water heaters and hot water storage tanks?
A: Because these systems often operate at high temperatures (60°C–90°C) using "aggressive" municipal water (containing chlorides). Under such conditions, tubing made of 304 or 316 often fails within 1–2 years due to pitting or stress corrosion cracking (SCC). TP444 offers a solution with superior long-term corrosion resistance and more stable pricing (as it contains no nickel).
