ASTM A249/A249M
Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes
ASTM A249/A249M specifies standard specification for nominal-wall-thickness welded tubes and heavily cold worked welded tubes made from the austenitic steels with various grades intended for such use as a boiler, superheater, heat exchanger, or condenser tubes.
ASTM A249/A249M requires a manufacturing process and a quality system that not only provide an excellent weld, but also condition the weld through proper cold working (forging) and heat treating (annealing) processes so that it closely approximates the structure and properties of the base metal. Only then will the tube have the proper corrosion resistance, stability at temperature, and mechanical properties needed for the most demanding applications.
Only fusion welding processes should be used to produce high-quality stainless, duplex, and nickel-alloy pressure tubing that will be used in demanding or critical applications.
Heat and product analysis shall conform to the requirements as to chemical composition for carbon, manganese, phosphorous, sulfur, silicon, chromium, nickel, molybdenum, nitrogen, copper, and others. All materials shall be furnished in the heat-treated condition in accordance with the required solution temperature and quenching method. When the final heat treatment is in a continuous furnace, the number of tubes of the same size and from the same heat in a lot shall be determined from the prescribed size of the tubes. Optional supplementary requirements are provided and, when one or more of these are desired, each shall be so stated in the order.
ASTM A249 Stainless Steel Tube Sizes
The tubing sizes and thicknesses usually furnished to this specification are 1/8 in. [3.2 mm] in inside diameter to 12 in. [304.8 mm] in outside diameter and 0.015 to 0.320 in. [0.4 to 8.1 mm], inclusive, in wall thickness. Tubing having other dimensions may be furnished, provided such tubes comply with all other requirements of ASTM A249/A249M
Mechanical property requirements do not apply to tubing smaller than 1/8 in. [3.2 mm] in inside diameter or 0.015 in. [0.4 mm] in thickness.
ASTM A249 Standard Stainless Tube Tolerances
Dimensional tolerances other than wall thickness tolerances shall be in accordance with Specification A1016/A1016M. Wall thickness tolerances shall be +/-10 % of nominal wall for all tubing sizes.
| Specified Outside Diameter, in. [mm] | OD, Over, in. [mm] | OD, Under, in. [mm] | Wall Thickness | Length, in. [mm] |
|---|---|---|---|---|
| Under 1 [25] | 0.004 [0.1] | 0.004 [0.11] | +/-10.0% | +1/8″ (3.18) – 0 |
| 1 to 11⁄2 [25 to 40], incl | 0.006 [0.15] | 0.006 [0.15] | +/-10.0% | +1/8″ (3.18) – 0 |
| Over 11⁄2 to 2 [40 to 50], excl | 0.008 [0.2] | 0.008 [0.2] | +/-10.0% | +1/8″ (3.18) – 0 |
| 2 to 21⁄2 [50 to 65], excl | 0.010 [0.25] | 0.010 [0.25] | +/-10.0% | +3/16″ [5] – 0 |
| 21⁄2 to 3 [65 to 75], excl | 0.012 [0.3] | 0.012 [0.3] | +/-10.0% | +3/16″ [5] – 0 |
| 3 to 4 [75 to 100], incl | 0.015 [0.38] | 0.015 [0.38] | +/-10.0% | +3/16″ [5] – 0 |
| Over 4 to 71⁄2 [100 to 200], incl | 0.015 [0.38] | 0.025 [0.64] | +/-10.0% | +3/16″ [5] – 0 |
| Over 71⁄2 to 9 [200 to 225], incl | 0.015 [0.38] | 0.045 [1.14] | +/-10.0% | +3/16″ [5] – 0 |
ASTM A 249 Stainless Steel Chemical Composition
ASTM A249/A249M covers nominal-wall-thickness welded tubes and heavily cold worked welded tubes made from the austenitic steels listed in Table below, with various grades intended for such use as boiler, superheater, heat exchanger, or condenser tubes.
| Grade | C | Mn | P | S | Si | Cr | Ni | Mo | Ti | Nb | N B |
| TP304 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-11.0 | … | … | … . | … |
| TP304H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-11.0 | … | … | … | … |
| TP304L | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 18.0-20.0 | 8.0-13.0 | … | … | … | … |
| TP310S | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 24.0-26.0 | 19.0-22.0 | 0.75 | |||
| TP316 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 11.0-14.0 | 2.00-3.00 | … | … | … |
| TP316L | 0.035 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 | … | … | … |
| TP316H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 16.0-18.0 | 11.0-14.0 | 2.00-3.00 | … | … | … |
| TP316Ti | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 16.0-18.0 | 10.0-14.0 | 2.00-3.00 | 5x(C+N)-0.70 | … | 0.10 |
| TP321 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-12.0 | … | 5C-0.70 | … | 0.10 |
| TP321H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-12.0 | … | 4C-0.60 | … | … |
| TP347 | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-13.0 | … | 10xC-1.00 | ||
| TP347H | 0.04-0.10 | 2.00 | 0.045 | 0.030 | 1.00 | 17.0-19.0 | 9.0-13.0 | … | … | 8xC-1.00 | … |
Grades TP304H, TP309H, TP309HCb, TP310H, TP310HCb, TP316H, TP321H, TP347H, and TP348H are modifications of Grades TP304, TP309S, TP309Cb, TP310S, TP310Cb, TP316, TP321, TP347, and TP348, and are intended for high-temperature service such as for superheaters and reheaters.
- ASTM A249 TP304
- ASTM A249 TP304l
- ASTM A249 TP316
- ASTM A249 TP316L
- ASTM A249 TP316Ti
- ASTM A249 TP321
ASTM A 249 Stainless Steel Mechanical Properties
The material shall conform to the prescribed tensile and hardness properties such as tensile strength, yield strength, elongation, and Rockwell hardness number. The steel shall undergo mechanical tests such as tension test, flattening test, flange test, reverse-bend test, hardness test, and hydrostatic or nondestructive electric test. The grain size of different grades of steel shall be determined in accordance with the test methods.
| Grade | UNS | Yield strength | Tensile Strength | Elongation in 2 in. or 50 mm | Hardness, Max | Hardness, Max |
| Designation | min ksi [MPa] | Min ksi [MPa] | min, %A, B | Rockwell | Brinell/Vickers | |
| TP304 | S30400 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP304L | S30403 | 25 [170] | 70 [485] | 35 | 90HB | 192HBW/200Hv |
| TP304H | S30409 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP304N | S30415 | 35 [240] | 80 [550] | 35 | 90HB | 192HBW/200Hv |
| TP310S | S31008 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP310H | S31009 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP316 | S31600 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP316L | S31603 | 25 [170] | 70 [485] | 35 | 90HB | 192HBW/200Hv |
| TP316H | S31609 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP316Ti | S31635 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP317 | S31700 | 30 [205] | 75 [515] | 34 | 90HB | 192HBW/200Hv |
| TP317L | S31703 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP321 | S32100 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP321H | S32109 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP347 | S34700 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
| TP347H | S34709 | 30 [205] | 75 [515] | 35 | 90HB | 192HBW/200Hv |
Surface Condition
The tubes, after final heat treatment, shall be chemically descaled or pickled free of scale. When bright annealing is used, pickling or chemical descaling is not necessary.
ASTM A249 Stainless Steel Tube Sizes and Weight
| Outside Diamete | Birmingham Wire Gauge (BWG) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 20 | 18 | 16 | 15 | 14 | 13 | 12 | 11 | 10 | |||
| In | mm | ||||||||||
| (0.889 mm) | (1.245 mm) | (1.651 mm) | (1.829 mm) | (2.108 mm) | (2.413 mm) | (2.769 mm) | (3.048 mm) | (3.403 mm) | |||
| Weight, kg/m (average wall ) | |||||||||||
| 1/4 | 0.250 | 6.350 | 0.12 | 0.16 | 0.19 | – | – | – | – | – | – |
| 5/16 | 0.313 | 7.950 | 0.15 | 0.21 | 0.25 | 0.28 | – | – | – | – | – |
| 3/8 | 0.375 | 9.525 | 0.19 | 0.25 | 0.31 | 0.34 | 0.39 | – | – | – | – |
| 1/2 | 0.500 | 12.700 | 0.25 | 0.34 | 0.45 | 0.49 | 0.55 | 0.61 | 0.68 | 0.72 | – |
| 5/8 | 0.625 | 15.875 | 0.33 | 0.45 | 0.58 | 0.64 | 0.71 | 0.80 | 0.89 | 0.97 | – |
| 3/4 | 0.750 | 19.050 | 0.40 | 0.55 | 0.72 | 0.77 | 0.88 | 0.98 | 1.12 | 1.20 | 1.31 |
| 7/8 | 0.875 | 22.225 | 0.46 | 0.64 | 0.83 | 0.92 | 1.04 | 1.18 | 1.32 | 1.44 | 1.58 |
| 1 | 1.000 | 25.400 | 0.54 | 0.74 | 0.97 | 1.06 | 1.21 | 1.37 | 1.55 | 1.68 | 1.92 |
| 1 1/8 | 1.125 | 28.575 | 0.61 | 0.83 | 1.10 | 1.21 | 1.37 | 1.56 | 1.76 | 1.92 | 2.11 |
| 1 1/4 | 1.250 | 31.750 | 0.68 | 0.94 | 1.23 | 1.35 | 1.53 | 1.76 | 1.96 | 2.16 | 2.40 |
| 1 3/8 | 1.375 | 34.925 | 0.74 | 1.03 | 1.35 | 1.49 | 1.70 | 1.93 | 2.19 | 2.40 | 2.65 |
| 1 1/2 | 1.500 | 38.100 | 0.82 | 1.13 | 1.49 | 1.64 | 1.87 | 2.17 | 2.40 | 2.63 | 2.92 |
| 1 3/4 | 1.750 | 44.450 | 0.97 | 1.32 | 1.74 | 1.92 | 2.20 | 2.50 | 2.84 | 3.10 | 3.44 |
| 2 | 2.000 | 50.800 | – | 1.52 | 1.99 | 2.20 | 2.53 | 2.89 | 3.27 | 3.59 | 3.97 |
| 2 1/4 | 2.250 | 57.150 | – | 1.73 | 2.26 | 2.48 | 2.87 | 3.26 | 3.70 | 4.06 | 4.51 |
| 2 3/8 | 2.375 | 60.325 | – | 1.81 | 2.38 | 2.63 | 3.02 | 3.44 | 3.93 | 4.30 | 4.78 |
| 2 1/2 | 2.500 | 63.500 | – | 1.91 | 2.52 | 2.78 | 3.18 | 3.66 | 4.14 | 4.54 | 5.04 |
| 2 7/8 | 2.875 | 73.025 | – | 2.20 | 2.90 | 3.20 | 3.68 | 4.20 | 4.79 | 5.25 | 5.83 |
| 3 | 3.000 | 76.200 | – | 2.31 | 3.04 | 3.35 | 3.85 | 4.39 | 5.00 | 5.49 | 6.10 |
| 3 1/2 | 3.500 | 88.900 | – | 2.69 | 3.56 | 3.93 | 4.51 | 5.15 | 5.86 | 6.44 | 7.17 |
| 4 | 4.000 | 101.60 | – | – | 4.11 | 4.54 | 5.21 | 5.95 | 6.80 | 7.47 | 8.30 |