ASTM A268 Tp410 Tp430 Tp439 Bright Annealed Heat Exchanger Tube

Why is it that in certain heat exchanger projects involving high temperatures or mildly corrosive environments-even when using stainless steel tubes that technically meet industry standards,issues such as difficult tube expansion, weld stress cracking, or unstable heat exchange efficiency frequently arise? The root cause often lies in whether the control of dimensional tolerances, wall thickness uniformity, and surface finish truly meets the rigorous demands of such operating conditions.

 

Our ASTM A268 TP410, TP430, and TP439 Bright Annealed (BA) heat exchanger tubes are specifically engineered for high-demand heat exchange systems, offering exceptional manufacturing quality and performance advantages. Regarding dimensional precision, all tubing strictly adheres to ASTM A268 standards; the outer diameter tolerance is controlled within ±0.3%, and wall thickness uniformity is excellent-with deviations typically ≤10%-thereby ensuring reliable sealing during tube sheet assembly and expansion processes, and effectively mitigating the risk of micro-cracks or leaks caused by uneven wall thickness or diameter deviations.

 

In terms of surface finish, we employ a Bright Annealing (BA) process to ensure a high degree of smoothness on both the inner and outer surfaces of the tubes, with a surface roughness (Ra) typically ≤0.8 μm. This not only reduces fluid resistance and enhances heat exchange efficiency but also effectively minimizes the propensity for scaling and corrosion, thereby providing a robust guarantee for long-term operational reliability.

 

ASTM A268 TP410, TP430, TP439 Bright Annealed Heat Exchanger Tube Specifications

Outside Diameter	6-203mm
Wall Thickness	0.5-25mm
Length	Up to 25m
Standard	ASTM A268, ASME SA268
Grade	TP410/TP405/TP420/TP430/TP430Ti/TP403/TP409/TP444/TP439/TP446,etc.
Delivery Condition	Pickled, Polished, Bright Annealed
Technique	Seamless/Welded
Application	Heat Exchanger, Heater, Condenser, Machining, Bearing Machining, API Service…
Marking	LOGO, Standard, Grade, Size, Heat Number.
Package	Woven bag, wooden case, or as per customer's requirement.
Quality Requirement	Mill Test Certificate (EN 10204/3.1); Third Part Inspection is acceptable.

 

Chemical Composition (wt. %) per ASTM A268

Element	TP410 (UNS S41000)	TP430 (UNS S43000)	TP439 (UNS S43035)
Carbon (C)	0.15% Max	0.12% Max	0.030% Max
Chromium (Cr)	11.5 – 13.5%	16.0 – 18.0%	17.0 – 19.0%
Manganese (Mn)	1.00% Max	1.00% Max	1.00% Max
Silicon (Si)	1.00% Max	1.00% Max	1.00% Max
Nickel (Ni)	0.75% Max	0.75% Max	0.50% Max
Titanium (Ti)	-	-	1.10% Max*
Phosphorus (P)	0.040% Max	0.040% Max	0.040% Max
Sulfur (S)	0.030% Max	0.030% Max	0.030% Max

 

Mechanical Properties:

Property	TP410	TP430	TP439
Tensile Strength (MPa)	≥ 415 (60 ksi)	≥ 415 (60 ksi)	≥ 415 (60 ksi)
Yield Strength (MPa)	≥ 205 (30 ksi)	≥ 205 (30 ksi)	≥ 205 (30 ksi)
Elongation (in 50mm)	≥ 20%	≥ 22%	≥ 22%
Hardness (Rockwell B)	≤ 90 HRB	≤ 89 HRB	≤ 89 HRB

 

What are the main differences between TP410, TP430, and TP439?

TP410 is a heat-treatable martensitic stainless steel offering moderate corrosion resistance, whereas TP430 is a 17% Cr-bearing ferritic stainless steel that exhibits superior corrosion resistance. TP439 is a titanium-stabilized ferritic stainless steel (low-carbon, high-chromium) with even more exceptional corrosion resistance, designed specifically to prevent carbide precipitation.

 

Non-Destructive Testing

Eddy Current Testing: Provides 100% coverage to detect minute defects within the tube wall.
Hydrostatic Testing: Maintains a standard pressure for a specified duration to ensure the absence of any leaks.
Additionally, we offer Air Under Water Testing, specifically designed for environments involving highly permeable gases.

Packaging and Marking:

The products shall be packaged in bundles or plywood crates, wrapped in plastic, and provided with appropriate protective measures to ensure seaworthy transport, or packaged in accordance with specific requirements.
Markings shall indicate whether the tubing is hot-worked or cold-worked, and shall include-but not be limited to-the following information: standard, grade, dimensions, heat number, and batch number.