seamless pipe is drawn from a single billet of steel material where the welded pipes are welded from sheets, strips or coils of the same grade of material. The seamless pipes have no welded seam. So they have less absolute roughness on the surface. In other words, the smls pipe has less surface deformities. The seamless pipes range in outer diameter from 4mm to 219mm for different grades of materials. The welded pipes can range from 5mm to 1219.2mm in outer diameters because they are welded from strips, sheets or coils. The welded and seamless steel pipe can be used interchangeably. In a few applications, the dimensional accuracy is important.

The applications such as equipment, tools or instruments need to have the pipes with high accuracy. At these instances, the seamless pipes are chosen. There are a few applications that need very large diameters. Oil and gas transmission pipes, large water supply lines and other fluid transfer lines have erw pipe types because the outer diameter is higher. There are different material grades such as austenitic stainless steels, duplex steels and high alloy steels. There are carbon steel types as well. The Welded Pipe and the seamless pipe types are seen in all material grades. The applications, the material grade and the environmental conditions influence the type of pipe as welded or seamless.

Seamless Pipe Sizes

Nominal Pipe Size Outside Diameter Schedule 5 S Schedule 10 S Schedule 20 S Schedule 40 S Schedule 80 S Schedule 160 S XXS
mm inch mm WT mm WEIGHT (KGM) WT mm WEIGHT (KGM) WT mm WEIGHT (KGM) WT mm WEIGHT (KGM) WT mm WEIGHT (KGM) WT mm WEIGHT (KGM) WT mm WEIGHT (KGM)
3 1/8 10.3 1.2 0.20 1.24 0.28 1.5 0.33 1.73 0.37 2.41 0.47 - - - -
6 1/4 13.7 1.2 0.37 1.65 0.49 2.00 0.58 2.24 0.630 3.02 0.80 - - - -
10 3/8 17.1 1.2 0.47 1.65 0.63 2.00 0.74 2.31 0.840 3.20 1.10 - - - -
15 1/2 21.3 1.65 0.80 2.11 1.00 2.30 1.07 2.77 1.27 3.73 1.62 4.75 1.94 7.47 2.55
20 3/4 26.7 1.65 1.03 2.11 1.28 2.55 1.52 2.87 1.69 3.91 2.20 5.56 2.90 7.82 3.64
25 1 33.4 1.65 1.30 2.77 2.09 2.55 1.94 3.38 2.50 4.55 3.24 6.35 4.24 9.09 5.45
32 1.1/4 42.2 1.65 1.65 2.77 2.70 3.00 2.90 3.56 3.39 4.85 4.47 6.35 5.61 9.70 7.77
40 1.1/2 48.3 1.65 1.91 2.77 3.11 3.00 3.55 3.68 4.05 5.08 5.41 7.14 7.25 11.1 10.18
50 2 60.3 1.65 2.40 2.77 3.93 3.00 4.24 3.91 5.44 5.54 7.48 8.74 11.11 11.07 13.44
65 2.1/2 73.0 2.11 3.69 3.05 5.26 4.00 6.81 5.16 8.63 7.01 11.41 9.53 14.91 14.02 20.39
80 3 88.9 2.11 4.51 3.05 6.45 4.00 8.37 5.49 11.29 7.62 15.27 11.1 21.30 15.24 27.68
100 4 114.3 2.11 5.84 3.05 8.36 4.50 12.18 6.02 16.07 8.56 22.32 13.49 33.54 17.12 41.03
125 5 141.3 2.77 9.47 3.40 11.57 5.00 16.80 6.55 21.8 9.53 30.97 15.88 49.11 19.05 57.43
150 6 168.3 2.77 11.32 3.40 13.84 6.35 25.36 7.11 28.26 10.97 42.56 18.25 67.53 21.95 79.22
200 8 219.1 2.77 14.79 3.76 19.96 6.35 33.31 8.18 42.55 12.7 64.64 23.01 111.27 22.23 107.92
250 10 273.1 3.40 22.63 4.19 27.78 6.35 41.77 9.27 60.31 12.7 96.01 28.58 172.33 25.40 155.15
300 12 323.8 3.96 31.25 4.57 36.00 6.35 49.7 9.53 73.88 12.7 132.05 33.32 238.76 25.40 186.97
350 14 355.6 3.96 34.36 4.78 41.3 7.92 67.80 11.13 94.59
ASTM A 312 TP 304
ASTM A 312 TP 316L
ASTM A 312 TP 317L
400 16 406.4 4.19 41.56 4.78 47.29 7.92 77.83 12.7 123.30
450 18 457.2 4.19 46.81 4.78 53.26 7.92 87.71 14.27 155.80
500 20 508.0 4.78 59.25 5.54 68.61 9.53 117.14 15.09 183.42
600 24 610.0s 5.54s 82.47 6.35 94.45 9.53 141.12 17.48 255.41

Seamless Pipe Material Grades

Material Pipes Fttg Flg Valves Bolts and Nuts
Carbon Steel A106 Gr A A234 Gr WPA A105 A216 Gr WCB A193 Gr B7
A194 Gr 2H
A106 Gr B A234 Gr WPB A105 A216 Gr WCB
A106 Gr C A234 Gr WPC A105 A216 Gr WCB
 
Carbon Steel
Alloy
High-Temp
A335 Gr P1 A234 Gr WP1 A182 Gr F1 A217 Gr WC1 A193 Gr B7
A194 Gr 2H
A335 Gr P11 A234 Gr WP11 A182 Gr F11 A217 Gr WC6
A335 Gr P12 A234 Gr WP12 A182 Gr F12 A217 Gr WC6
A335 Gr P22 A234 Gr WP22 A182 Gr F22 A217 Gr WC9
A335 Gr P5 A234 Gr WP5 A182 Gr F5 A217 Gr C5
A335 Gr P9 A234 Gr WP9 A182 Gr F9 A217 Gr C12
 
Carbon Steel
Alloy
Low-Temp
A333 Gr 6 A420 Gr WPL6 A350 Gr LF2 A352 Gr LCB A320 Gr L7
A194 Gr 7
A333 Gr 3 A420 Gr WPL3 A350 Gr LF3 A352 Gr LC3
 
Austenitic
Stainless
Steel
A312 Gr TP304 A403 Gr WP304 A182 Gr F304 A182 Gr F304 A193 Gr B8
A194 Gr 8
A312 Gr TP316 A403 Gr WP316 A182 Gr F316 A182 Gr F316
A312 Gr TP321 A403 Gr WP321 A182 Gr F321 A182 Gr F321
A312 Gr TP347 A403 Gr WP347 A182 Gr F347 A182 Gr F347
Material Pipes Fttg Flg Valves Bolts and Nuts

Welded Pipe Size Chart

NPS
(DN)
ID OD
IN
(MM)
WT
IN
(MM)
WEIGHT
LB/FT
(KG/M)
1/8
(6)
5S 0.405
(10.3)
Note 1 ...
1/8
(6)
10S 0.405
(10.3)
0.049
(1.24)
Note 1
0.19
(0.28)
1/8
(6)
40S 0.405
(10.3)
0.068
(1.73)
0.24
(0.37)
1/8
(6)
80S 0.405
(10.3)
0.095
(2.41)
0.31
(0.47)
1/4
(8)
5S 0.54
(13.7)
Note 1 ...
1/4
(8)
10S 0.54
(13.7)
0.065
(1.65)
Note 1
0.33
(0.49)
1/4
(8)
40S 0.54
(13.7)
0.088
(2.24)
0.43
(0.63)
1/4
(8)
80S 0.54
(13.7)
0.119
(3.02)
0.54
(0.8)
3/8
(10)
5S 0.675
(17.1)
Note 1 ...
3/8
(10)
10S 0.675
(17.1)
0.065
(1.65)
Note 1
0.42
(0.63)
3/8
(10)
40S 0.675
(17.1)
0.091
(2.31)
0.57
(0.84)
3/8
(10)
80S 0.675
(17.1)
0.126
(3.2)
0.74
(1.1)
1/2
(15)
5S 0.84
(21.3)
0.065
(1.65)
Note 1
0.54
(0.8)
1/2
(15)
10S 0.84
(21.3)
0.083
(2.11)
Note 1
0.67
(1.0)
1/2
(15)
40S 0.84
(21.3)
0.109
(2.77)
0.85
(1.27)
1/2
(15)
80S 0.84
(21.3)
0.147
(3.73)
1.09
(1.62)
3/4
(20)
5S 1.05
(26.7)
0.065
(1.65)
Note 1
0.68
(1.02)
3/4
(20)
10S 1.05
(26.7)
0.083
(2.11)
Note 1
0.86
(1.28)
3/4
(20)
40S 1.05
(26.7)
0.113
(2.87)
1.13
(1.69)
3/4
(20)
80S 1.05
(26.7)
0.154
(3.91)
1.48
(2.2)
1
(25)
5S 1.315
(33.4)
0.065
(1.65)
Note 1
0.87
(1.29)
1
(25)
10S 1.315
(33.4)
0.109
(2.77)
Note 1
1.41
(2.09)
1
(25)
40S 1.315
(33.4)
0.133
(3.38)
1.68
(2.5)
1
(25)
80S 1.315
(33.4)
0.179
(4.55)
2.17
(3.24)

(32)
5S 1.66
(42.2)
0.065
(1.65)
Note 1
1.11
(1.65)

(32)
10S 1.66
(42.2)
0.109
(2.77)
Note 1
1.81
(2.69)

(32)
40S 1.66
(42.2)
0.14
(3.56)
2.27
(3.39)

(32)
80S 1.66
(42.2)
0.191
(4.85)
3.0
(4.47)

(40)
5S 1.9
(48.3)
0.065
(1.65)
Note 1
1.28
(1.9)

(40)
10S 1.9
(48.3)
0.109
(2.77)
Note 1
2.09
(3.11)

(40)
40S 1.9
(48.3)
0.145
(3.68)
2.72
(4.05)

(40)
80S 1.9
(48.3)
0.2
(5.08)
3.63
(5.41)
2
(50)
5S 2.375
(60.3)
0.065
(1.65)
Note 1
1.61
(2.39)
2
(50)
10S 2.375
(60.3)
0.109
(2.77)
Note 1
2.64
(3.93)
2
(50)
40S 2.375
(60.3)
0.154
(3.91)
3.66
(5.44)
2
(50)
80S 2.375
(60.3)
0.218
(5.54)
5.03
(7.48)

(65)
5S 2.875
(73)
0.083
(2.11)
Note 1
2.48
(3.69)

(65)
10S 2.875
(73)
0.12
(3.05)
Note 1
3.53
(5.26)

(65)
40S 2.875
(73)
0.203
(5.16)
5.8
(8.63)

(65)
80S 2.875
(73)
0.276
(7.01)
7.67
(11.41)
3
(80)
5S 3.5
(88.9)
0.083
(2.11)
Note 1
3.03
(4.52)
3
(80)
10S 3.5
(88.9)
0.12
(3.05)
Note 1
4.34
(6.46)
3
(80)
40S 3.5
(88.9)
0.216
(5.49)
7.58
(11.29)
3
(80)
80S 3.5
(88.9)
0.3
(7.62)
10.26
(15.27)

(90)
5S 4.0
(101.6)
0.083
(2.11)
Note 1
3.48
(5.18)

(90)
10S 4.0
(101.6)
0.12
(3.05)
Note 1
4.98
(7.41)

(90)
40S 4.0
(101.6)
0.226
(5.74)
9.12
(13.57)

(90)
80S 4.0
(101.6)
0.318
(8.08)
12.52
(18.64)
4
(100)
5S 4.5
(114.3)
0.083
(2.11)
Note 1
3.92
(5.84)
4
(100)
10S 4.5
(114.3)
0.12
(3.05)
Note 1
5.62
(8.37)
4
(100)
40S 4.5
(114.3)
0.237
(6.02)
10.8
(16.08)
4
(100)
80S 4.5
(114.3)
0.337
(8.56)
15.0
(22.32)
5
(125)
5S 5.563
(141.3)
0.109
(2.77)
Note 1
6.36
(9.46)
5
(125)
10S 5.563
(141.3)
0.134
(3.4)
Note 1
7.78
(11.56)
5
(125)
40S 5.563
(141.3)
0.258
(6.55)
14.63
(21.77)
5
(125)
80S 5.563
(141.3)
0.375
(9.53)
20.8
(30.97)
6
(150)
5S 6.625
(168.3)
0.109
(2.77)
Note 1
7.59
(11.31)
6
(150)
10S 6.625
(168.3)
0.134
(3.4)
Note 1
9.3
(13.83)
6
(150)
40S 6.625
(168.3)
0.28
(7.11)
18.99
(28.26)
6
(150)
80S 6.625
(168.3)
0.432
(10.97)
28.6
(42.56)
8
(200)
5S 8.625
(219.1)
0.109
(2.77)
Note 1
9.92
(14.78)
8
(200)
10S 8.625
(219.1)
0.148
(3.76)
Note 1
13.41
(19.97)
8
(200)
40S 8.625
(219.1)
0.322
(8.18)
28.58
(42.55)
8
(200)
80S 8.625
(219.1)
0.5
(12.7)
43.43
(64.64)
10
(250)
5S 10.75
(273)
0.134
(3.4)
Note 1
15.21
(22.61)
10
(250)
10S 10.75
(273)
0.165
(4.19)
Note 1
18.67
(27.78)
10
(250)
40S 10.75
(273)
0.365
(9.27)
40.52
(60.29)
10
(250)
80S 10.75
(273)
0.5
(12.7)
Note 2
54.79
(81.53)
12
(300)
5S 12.75
(323.8)
0.156
(3.96)
Note 1
21.0
(31.24)
12
(300)
10S 12.75
(323.8)
0.18
(4.57)
Note 1
24.19
(35.98)
12
(300)
40S 12.75
(323.8)
0.375
(9.53)
Note 2
49.61
(73.86)
12
(300)
80S 12.75
(323.8)
0.5
(12.7)
Note 2
65.48
(97.44)
14
(350)
5S 14.0
(355.6)
0.156
(3.96)
Note 1
23.09
(34.34)
14
(350)
10S 14.0
(355.6)
0.188
(4.78)
Notes
(1),(2)
27.76
(41.36)
14
(350)
40S 14.0
(355.6)
0.375
(9.53)
Note 2
54.62
(81.33)
14
(350)
80S 14.0
(355.6)
0.5
(12.7)
Note 2
72.16
(107.4)
16
(400)
5S 16.0
(406.4)
0.165
(4.19)
Note 1
27.93
(41.56)
16
(400)
10S 16.0
(406.4)
0.188
(4.78)
Notes
(1),(2)
31.78
(47.34)
16
(400)
40S 16.0
(406.4)
0.375
(9.53)
Note 2
62.64
(93.27)
16
(400)
80S 16.0
(406.4)
0.5
(12.7)
Note 2
82.85
(123.31)
18
(450)
5S 18.0
(457)
0.165
(4.19)
Note 1
31.46
(46.79)
18
(450)
10S 18.0
(457)
0.188
(4.78)
Notes
(1),(2)
35.8
(53.31)
18
(450)
40S 18.0
(457)
0.375
(9.53)
Note 2
70.65
(...)
18
(450)
80S 18.0
(457)
0.5
(12.7)
Note 2
93.54
(...)
20
(500)
5S 20.0
(508)
0.188
(4.78)
Note 1
39.82
(59.32)
20
(500)
10S 20.0
(508)
0.218
(5.54)
Notes
(1),(2)
46.1
(68.65)
20
(500)
40S 20.0
(508)
0.375
(9.53)
Note 2
78.67
(117.15)
20
(500)
80S 20.0
(508)
0.5
(12.7)
Note 2
104.23
(155.13)
22
(550)
5S 22.0
(559)
0.188
(4.78)
Note 1
43.84
(65.33)
22
(550)
10S 22.0
(559)
0.218
(5.54)
Notes
(1),(2)
50.76
(75.62)
22
(550)
40S 22.0
(559)
... ...
22
(550)
80S 22.0
(559)
... ...
24
(600)
5S 24.0
(610)
0.218
(5.54)
Note 1
55.42
(82.58)
24
(600)
10S 24.0
(610)
0.25
(6.35)
Note 1
63.47
(94.53)
24
(600)
40S 24.0
(610)
0.375
(9.53)
Note 2
94.71
(141.12)
24
(600)
80S 24.0
(610)
0.5
(12.7)
Note 2
125.61
(187.07)
30
(750)
5S 30.0
(762)
0.25
(6.35)
Note 1
79.51
(118.34)
30
(750)
10S 30.0
(762)
0.312
(7.92)
Note 1
99.02
(147.29)
30
(750)
40S 30.0
(762)
... ...
30
(750)
80S 30.0
(762)
... ...

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