Click to enlarge
Product Overview
ASTM A249 Welded Stainless Steel Tubes
ASTM A249/SA249 welded austenitic stainless steel tubes for boiler, superheater, heat exchanger and condenser service, in solution annealed heat-treated condition.
Product Introduction
Standard Scope: Welded austenitic stainless steel tubes for boiler, superheater, heat exchanger, condenser service. All tubes shall be supplied in solution annealed heat-treated condition. Not for general structural decoration.
1. Common Material Grades
| ASTM Grade | UNS No. | EN Number | Key Characteristic | Density (g/cm³) | Typical Application |
|---|---|---|---|---|---|
| TP304 | S30400 | 1.4301 | General purpose austenitic | 7.93 | Heat exchanger, condenser |
| TP304L | S30403 | 1.4307 | Low carbon, resist intergranular corrosion | 7.93 | Post-weld corrosion environment |
| TP304H | S30409 | 1.4948 | High carbon, high-temperature creep resistance | 7.93 | Superheater, high-temp boiler |
| TP316 | S31600 | 1.4401 | Molybdenum added, better corrosion resistance | 7.98 | Chemical heat exchanger |
| TP316L | S31603 | 1.4404 | Low carbon molybdenum grade | 7.98 | Chloride-containing medium |
| TP316H | S31609 | 1.4436 | High carbon for elevated temperature | 7.98 | High-temp chemical equipment |
| TP321 | S32100 | 1.4541 | Ti stabilized, prevent weld precipitation | 7.93 | Moderate high-temperature service |
| TP321H | S32109 | 1.4878 | High carbon stabilized grade | 7.93 | Superheater tubes |
| TP347 | S34700 | 1.4550 | Nb stabilized for welding | 7.93 | Welded high-temp components |
| TP347H | S34709 | 1.4961 | High carbon Nb stabilized | 7.93 | Power plant boiler tubes |
| TP310S | S31008 | 1.4845 | High Cr/Ni, oxidation resistant | 7.98 | High-temperature furnace equipment |
Mechanical Properties (Solution Annealed Condition, A249 Requirement)
| Grade Group | Tensile Strength Min. (MPa) | Yield Strength Min. (MPa) | Elongation 50 mm Min. (%) | Max Hardness |
|---|---|---|---|---|
| TP304 / TP316 / TP321 / TP347 | 515 | 205 | 35 | 192 HBW / 90 HRB |
| TP304L / TP316L | 485 | 170 | 35 | 192 HBW / 90 HRB |
| H-series grades (304H, 316H, 321H, 347H) | 515 | 205 | 35 | 192 HBW |
2. Dimension General Range for A249 Round Tubes
| Item | Specification |
|---|---|
| Outer Diameter (OD) | 3.2 mm ~ 304.8 mm (max 12 inch) |
| Wall Thickness (WT) | 0.4 mm ~ 8.1 mm |
| Standard Length | 6000 mm fixed length; random length 4000-7000 mm; custom cut-to-length available |
| Tube End | Plain end, deburred |
| Surface Finish | Pickled & annealed, Bright Annealed (BA) |
| Weld condition | Weld bead internally removed; full solution annealing after welding |
Dimensional Tolerances (A249 / A450M)
| Parameter | Permissible Tolerance |
|---|---|
| Outer Diameter | OD ≤25.4 mm: ±0.10 mm; 25.4-38.1 mm: ±0.15 mm; 38.1-50.8 mm: ±0.20 mm; >50.8 mm: ±0.5% OD |
| Wall Thickness | ±10% of nominal wall thickness |
| Straightness | Max 1 mm per meter |
| Length (≤6 m) | +6 mm / 0 mm |
3. Popular Commercial Size Reference Table (A249 Round Tube)
Theoretical weight formula for 304 grade: W(kg/m) = 0.02491 × (OD - WT) × WT
| Outer Diameter OD (mm) | Common Wall Thickness (mm) | Theoretical Weight TP304 (kg/m) |
|---|---|---|
| 12.7 | 1.0 / 1.2 / 1.5 | 0.28 / 0.33 / 0.40 |
| 19.05 | 1.2 / 1.5 / 1.65 | 0.52 / 0.64 / 0.70 |
| 25.4 | 1.2 / 1.5 / 2.0 | 0.71 / 0.87 / 1.14 |
| 31.75 | 1.5 / 2.0 / 2.11 | 1.11 / 1.45 / 1.52 |
| 38.1 | 1.5 / 2.0 / 2.77 | 1.34 / 1.76 / 2.38 |
| 42.4 | 2.0 / 2.5 / 2.77 | 1.97 / 2.43 / 2.67 |
| 50.8 | 2.0 / 2.5 / 3.05 | 2.38 / 2.94 / 3.54 |
| 63.5 | 2.5 / 3.0 / 3.5 | 3.70 / 4.38 / 5.04 |
| 76.2 | 2.5 / 3.0 / 3.40 | 4.47 / 5.30 / 5.97 |
| 88.9 | 3.0 / 3.5 / 4.0 | 6.22 / 7.21 / 8.17 |