ASTM A791 Ferritic Stainless Steel Tube
ASTM A791 409 Stainless Steel Tubing, ASTM A791 Polished Stainless Steel Tubes
ASTM A791 specification covers welded, unannealed, ferritic stainless steel tubing intended for high-temperature and corrosive serice where post-weld heat treatment is not necessary for corrosion resistance. ASTM A791 type 444 tubing grades are com-monly known as the "straight-chromium" types and are characterized by being ferromagnetic. Welded Unannealed Ferritic Stainless Steel Tubing high-chromium, ferritic alloys are sensitive to notch-brittleness on slow cooling to ordinary temperatures. ASTM A791 welded tubing features should be recognized in the use of thest materials. ASTM A791 409 Tubes requiring additional testing or examination is referred to the Supple-mentary Requirements or Ordering Information Section, or both. Users requiring a tubular product with post-weld heat treatment are referred to Specification A 268 /A 268M. We have most reputed name as a ASTM A791 Stainless Steel Welded Tube supplier.
ASTM A791 Welded Tubing Specifications
| Specifications | ASTM A791/ ASME SA791 | |
| s Grades | ASTM A791 TP409, ASTM A791 TP439, ASTM A791 TP444 | |
| O.D. | 6mm-660mm | |
| Wall Thickness | 0.25mm | |
| AST Schedule | SCH. 5, 10, 20, 30, 40, 60, 80, 100, 120, 140, 160, XXS. | |
| Type | Welded | |
| Finish | 2B MIll Finish , No.4 finish, BA Finish, 400 Grit Finish, 550 Grit Finish, 600 Grit Finish | |
| Length | Single Random, Double Random & Cut Length | |
| Types | Round, Square, Rectangle | |
| ASTM A791 Products | ASTM A791 409 Stainless Steel Round Tubes, SS 409 rectangle tubes, SS444 No.4 Finish Tube, SS439 Polished Tubes, ASTM A791 409 Tubing, ASTM A791 409 Welded Tubing, ASTM A791 Welded Polished Tubes, ASTM A791 409 Stainless Steel Square Tube |
ASTM A791 Equivalent
| GRADE | UNS NO | DIN/WERKSTOFF |
|---|---|---|
| ASTM A791 409 | S40900 | 1.4301 |
| ASTM A791 439 | S43900 | 1.4510 |
| ASTM A791 444 | S44400 | 1.4521 |
Chemical Composition Of ASTM A791
| Grade | Mfg. Process | Chemical composition(%) | ||||||||
| C | Si | Mn | P | S | Ni | Cr | Mo | Others | ||
| TP409 | E, W | 0.08Max | 1.00Max | 1.0Max | 0.045Max | 0.045Max | 0.50Max | 10.50~11.75 | – | Ti 6C~0.75 |
| TP439 | E, W | 0.07Max | 1.00Max | 1.00Max | 0.040Max | 0.030Max | 0.50Max | 17.00~19.00 | N 0.04Max Al 0.15Max | Ti 0.20+ 4(C+N)~1.10 |
| TPXM-27 | E, W | 0.01Max | 0.40Max | 0.40Max | 0.02Max | 0.02Max | 0.50Max | 25.0~27.0 | 0.75~1.50 | Cu 0.2Max N 0.015Max |
| TPXM-33 | E, W | 0.06Max | 0.75Max | 0.75Max | 0.040Max | 0.020Max | 0.50Max | 25.0~27.0 | Mo 0.75~1.50 Ti 7(C+N) 0.20Min 1.00Max | Cu 0.20Max N 0.040Max |
| 25-4-4 | E, W | 0.025Max | 0.75Max | 0.75Max | 0.040Max | 0.030Max | 3.5~4.5 | 24.5~26.0 | 3.5~4.2 | N 0.035Max Ti+Cb 0.2+4(C+N)~0.080 |
| 26-3-3 | E, W | 0.030Max | 1.00Max | 1.00Max | 0.040Max | 0.030Max | 1.0~3.50 | 25.0~28.0 | 3.0~3.50 | N 0.040Max Ti+Cb=6(C+N) 0.20Min 1.00Max |
| 29-4 | E, W | 0.010Max | 0.20Max | 0.30Max | 0.025Max | 0.15Max | 28.0~30.0 | 3.5~4.2 | – | Cu 0.15Max N 0.020Max |
| 29-4-2 | E, W | 0.010Max | 0.20Max | 0.30Max | 0.025Max | 0.20Max | 2.0~2.5 | 28.0~30.0 | 3.5~4.2 | Cu 0.15Max N 0.020Max |
| 18-2 | E, W | 0.030Max | 1.00Max | 1.00Max | 0.040Max | 1.00Max | 1.00Max | 28.0~30.0 | 3.60~4.20 | N 0.045Max (Ti+Cb)=6(C+N) 0.20Min 1.00Max |
| 29-4C | E, W | 1.00Max | 1.00Max | 1.00Max | 0.040Max | 1.00Max | 1.00Max | 17.5~2.50 | 1.75~2.50 | N 0.035Max (Ti+Cb)=6(C+N) 0.20Min 1.00Max |
ASTM A791 Mechanical Properties
| Grade | Tensile Test MPa or N/mm2 | Remaks (Similar to JIS) | Possibility Temperature | |
| Min Yield point | Tensile Strength | |||
| TP409 | 205 | 380 | for High Temperature Service | – |
| TP439 | 205 | 415 | – | |
| TPXM-27 | 275 | 450 | – | |
| TPXM-33 | 310 | 415 | – | |
| 25-4-4 | 515 | 620 | – | |
| 26-3-3 | 450 | 585 | – | |
| 29-4 | 415 | 550 | – | |
| 29-4-2 | 415 | 550 | – | |
| 18-2 | 240 | 415 | – | |
| 29-4C | 415 | 515 | – | |
Tensile Requirement of ASTM A791 Welded Tubing
| Grade | UNS Designation |
Tensile Strength, min, ksi [MPa] |
Yield Strength, min, ksi [MPa] |
ElongationA in 2 in. or 50mm min, % |
| TP 409 | S40900 | 55[380] | 30[205] | 20 |
| TP 439 | S40335 | 60[415] | 30[205] | 20 |
| TP XM-27 | S44627 | 65[450] | 40[275] | 18 |
| TP XM-33 | S44626 | 68[410] | 45[310] | 20 |
| 25-4-4 | S44635 | 90[620] | 75[515] | 12 |
| 26-3-3 | S44660 | 85[585] | 65[450] | 20 |
| 29-4 | S44700 | 80[550] | 60[415] | 20 |
| 29-4-2 | S44800 | 80[550] | 60[415] | 20 |
| 18-2 | S44400 | 60[415] | 35[240] | 20 |
| 29-4C | S44735 | 75[515] | 60[415] | 12 |
ASTM A791 Welded Tubing Hardness Requirements
| Grade | Brinell Hardness, max | Rockwell Hardness, B Scale, max |
| TP 409 | 207 | 95 |
| TP 439 | 207 | 95 |
| TP XM-27 | 241 | 100 |
| TP XM-33 | 241 | 100 |
| 25-4-4 | … | 30 |
| 26-3-3 | 265 | 25A |
| 29-4 | 241 | 100 |
| 29-4-2 | 241 | 100 |
| 18-2 | 217 | 95 |
| 29-4C | … | 25A |
Permissible Variations in ASTM A791 Welded Tubing Dimensions
| Group | Size, Outside Dianmeter, in. [mm] |
Permissible Variations in Outside Diameter, in.[mm] |
Permissible Variations in Wall Thickness, % |
Permissible Variations in Cut Lneght, in.[mm]A |
Thin Walled TubesC | |
| 1 | Up to 1/2[12.7], excl | ±0.0055 [0.13] | ±15 | 1/8 [3] | 0 | … |
| 2 | 1/2 to 1 1/2[12.7 to 38.1], excl | ±0.0005 [0.13] | ±10 | 1/8 [3] | 0 | less than 0.065 in. [1.6mm] nominal |
| 3 | 1 1/2 to 3 1/2[38.1 to 88.9], excl | ±0.0010 [0.25] | ±10 | 3/16 [5] | 0 | less than 0.095in. [2.4mm] nominal |
| 4 | 3 1/2 to 5 1/2[88.9 to 139.7], excl | ±0.0015 [0.38] | ±10? | 3/16 [5] | 0 | less than 0.150 in. [3.8mm] nominal |
| 5 | 5 1/2 to 8[139.7 to 203.2], incl | ±0.0030 [0.76] | ±10 | 3/16 [5] | 0 | less than 0.150 in. [3.8mm] nominal |
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