ASTM A791 Ferritic Stainless Steel Tube




ASTM A791 409 Stainless Steel Tubing, ASTM A791 Polished Stainless Steel Tubes

Welded Mechanical Tubing

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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