Why do stainless steel seamless tubes still face issues such as surface contamination, dimensional instability, or reduced service life in precision equipment, food-grade, or high-purity systems? The key lies in whether the tube's surface quality, dimensional accuracy, and material purity truly meet the stringent requirements of these high-standard applications.
GNEE supplies high-quality ASTM A269 TP304 Bright Annealed Stainless Steel Seamless Tubes, specifically designed for clean and high-precision environments. Through strict smelting control and spectrometric analysis, we ensure a stable chemical composition of Cr 18–20%, Ni 8–10.5%, and C ≤0.08%. All tubes undergo Bright Annealing (BA) under a protective atmosphere, resulting in clean, smooth, and oxide-free inner and outer surfaces. The surface roughness (Ra) is typically controlled within ≤0.6–0.8 μm, effectively reducing media adhesion and bacterial growth, making it ideal for food processing, pharmaceutical, and precision fluid systems.
In terms of dimensional tolerances, we strictly comply with ASTM A269 standards while applying tighter internal controls. Outer diameter tolerance is maintained within ±0.2%–0.3%, and wall thickness uniformity is kept within ±10%, ensuring excellent compatibility in automated systems and precision assemblies. This significantly reduces installation difficulties and minimizes sealing risks caused by dimensional deviations.
Specifications: ASTM A/ASME SA269
Tubes Sizes (Seamless): 1/2" NB - 16" NB
Pipes and Tubes Sizes (ERW): 1/2" NB - 24" NB
Pipes and Tubes Sizes (EFW): 6" NB - 100" NB
Pipes and Tubes Wall Thickness available: Schedule 5S - Schedule XXS (heavier on request)
Pipe and Tubes Other Materials Testing: NACE MR0175, H2 SERVICE, OXYGEN SERVICE, CRYO SERVICE, etc.
Dimensions: All Pipe is manufactured and inspected/tested to the relevant standards including ASTM, ASME and API etc.
ASTM A269 Standard Tubing Chemical Composition
| SS GRADE | ASTM A269/SA 269 CHEMICAL COMPOSITION % MAXIMUM | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| C | MN | P | S | SI | CR | NI | MO | N B | NB | TI | |
| TP304 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-11.0 | --- | --- | --- | --- |
ASME SA269 Tubes Mechanical Properties
| SS GRADE | HEAT TREATMENT | TEMPERURE F (C) MINIMUM | HARDNESS | |
|---|---|---|---|---|
| BRINELL | ROCKWELL | |||
| TP304 | Solution | 1900 (1040) | 192HBW/ 200HV | 90HRB |
SA269 tubing Tolerance
| OD, INCH | OD TOLERANCE INCH(MM) | WT TOLERANCE % | LENGTH TOLERNACE INCH(MM) | |
|---|---|---|---|---|
| + | - | |||
| ≤1 /2 | ± 0.005 ( 0.13 ) | ±15 | 1 /8 ( 3.2 ) | 0 |
| > 1 /2~1 1 /2 | ±0.005(0.13) | ±10 | 1 /8(3.2) | 0 |
| > 1 1 /2~< 3 1 /2 | ± 0.010(0.25) | ±10 | 3 /16(4.8) | 0 |
| > 3 1 /2~< 5 1 /2 | ± 0.015(0.38) | ±10 | 3 /16(4.8) | 0 |
| > 5 1 /2~< 8 | ± 0.030(0.76) | ±10 | 3 /16(4.8) | 0 |
| 8~< 12 | ± 0.040(1.01) | ±10 | 3 /16(4.8) | 0 |
| 12~< 14 | ± 0.050(1.26) | ±10 | 3 /16(4.8) | 0 |
Can A269 TP304 BA tubes be welded?
TP304 has excellent weldability using TIG (GTAW) or Orbital welding. However, welding will heat-tint the bright surface near the joint. If the application requires a 100% mirror finish, post-weld polishing or passivating may be necessary.
ASTM A269 TP304 Bright Annealed pipe Application
Chemical and petrochemical
Power generation
Renewable energy
Pulp and Paper
Process piping
Pharmaceutical
Food and beverage
Oil and gas
GNEE typically mandates 100% Non-Destructive Testing (NDT).
Non-Destructive Testing (NDT): Eddy Current Testing is commonly employed-serving as an alternative to hydrostatic testing-to ensure that the interior of seamless tubes is free from minute cracks or pinholes.
Hardness Testing: Standard A269 stipulates that hardness levels must not be excessively high (typically requiring Rockwell B ≤ 90); otherwise, the tubes are prone to cracking during on-site bending operations.
Certification Requirements: Compliance with the EN 10204 3.1 certification standard is mandatory (and in some instances, the more rigorous 3.2 third-party inspection is also required).
Packaging and Protection
Given the highly delicate surface finish of BA tubes, the quality of the packaging directly determines the condition of the goods upon arrival.
Individual Packaging: Each tube must be enclosed in a separate plastic sleeve.
End Protection: Robust plastic end caps must be fitted to prevent deformation of the tube ends and internal contamination.
Outer Packaging: Fumigation-free plywood crates must be used.
