DIMENSIONS OF STEEL TUBES FOR BOILER / HEAT EXCHANGER

The key dimensions for standard steel tubes are: outside / inside diameter and wall thickness (which can be expressed either in BWG - Birmingham wire gauge - or SWG - Standard wire gauge). These sizes are shown in the tables below:

BWG GAUGE

(Tube OD / ID and wall thickness by BWG gauge)

Tube Wall Thickness Chart
Tube OD Gauge of tube
00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24  
Wall Thickness (Inches)
0.380 0.340 0.300 0.284 0.259 0.238 0.220 0.203 0.180 0.165 0.148 0.134 0.120 0.109 0.095 0.083 0.072 0.065 0.058 0.049 0.042 0.035 0.032 0.028 0.025 0.022  
1/4"                         0.010 0.032 0.060 0.084 0.106 0.120 0.134 0.152 0.166 0.180 0.186 0.194 0.200 0.206 Tube I.D.
3/8"                 0.015 0.045 0.079 0.107 0.135 0.157 0.185 0.209 0.231 0.245 0.259 0.277 0.291 0.305 0.311 0.319 0.325 0.331
1/2"           0.024 0.060 0.094 0.140 0.170 0.204 0.232 0.260 0.282 0.310 0.334 0.356 0.370 0.384 0.402 0.416 0.430 0.436 0.444 0.450 0.456
5/8"     0.025 0.057 0.107 0.149 0.185 0.219 0.265 0.295 0.329 0.357 0.385 0.407 0.435 0.459 0.481 0.495 0.509 0.527 0.541 0.555 0.561 0.569 0.575 0.581
3/4"   0.070 0.150 0.182 0.232 0.274 0.310 0.344 0.390 0.420 0.454 0.482 0.510 0.532 0.560 0.584 0.606 0.620 0.634 0.652 0.666 0.680 0.686 0.694 0.700 0.706
7/8" 0.115 0.195 0.275 0.307 0.357 0.399 0.435 0.469 0.515 0.545 0.579 0.607 0.635 0.657 0.685 0.709 0.731 0.745 0.759 0.777 0.791 0.805 0.811 0.819 0.825 0.831
1" 0.240 0.320 0.400 0.432 0.482 0.524 0.560 0.594 0.640 0.670 0.704 0.732 0.760 0.782 0.810 0.834 0.856 0.870 0.884 0.902 0.916 0.930 0.936 0.944 0.950 0.956
1 1/8" 0.365 0.445 0.525 0.557 0.607 0.649 0.685 0.719 0.765 0.795 0.829 0.857 0.885 0.907 0.935 0.959 0.981 0.995 1.009 1.027 1.041 1.055 1.061 1.069 1.075 1.081
1 1/4" 0.490 0.570 0.650 0.682 0.732 0.774 0.810 0.844 0.890 0.920 0.954 0.982 1.010 1.032 1.060 1.084 1.106 1.120 1.134 1.152 1.166 1.180 1.186 1.194 1.200 1.206
1 1/2" 0.740 0.820 0.900 0.932 0.982 1.024 1.060 1.094 1.140 1.170 1.204 1.232 1.260 1.282 1.310 1.334 1.356 1.370 1.384 1.402 1.416 1.430 1.436 1.444 1.450 1.456
1 3/4" 0.990 1.070 1.150 1.182 1.232 1.274 1.310 1.344 1.390 1.420 1.454 1.482 1.510 1.532 1.560 1.584 1.606 1.620 1.634 1.652 1.666 1.680 1.686 1.694 1.700 1.706
2" 1.240 1.320 1.400 1.432 1.482 1.524 1.560 1.594 1.640 1.670 1.704 1.732 1.760 1.782 1.810 1.834 1.856 1.870 1.884 1.902 1.916 1.930 1.936 1.944 1.950 1.956
2 1/4" 1.490 1.570 1.650 1.682 1.732 1.774 1.810 1.844 1.890 1.920 1.954 1.982 2.010 2.032 2.060 2.084 2.106 2.120 2.134 2.152 2.166 2.180 2.186 2.194 2.200 2.206
2 1/2" 1.740 1.820 1.900 1.932 1.982 2.024 2.060 2.094 2.140 2.170 2.204 2.232 2.260 2.282 2.310 2.334 2.356 2.370 2.384 2.402 2.416 2.430 2.436 2.444 2.450 2.456
2 3/4" 1.990 2.070 2.150 2.182 2.232 2.274 2.310 2.344 2.390 2.420 2.454 2.482 2.510 2.532 2.560 2.584 2.606 2.620 2.634 2.652 2.666 2.680 2.686 2.694 2.700 2.706
3" 2.240 2.320 2.400 2.432 2.482 2.524 2.560 2.594 2.640 2.670 2.704 2.732 2.760 2.782 2.810 2.834 2.856 2.870 2.884 2.902 2.916 2.930 2.936 2.944 2.950 2.956
3 1/4" 2.490 2.570 2.650 2.682 2.732 2.774 2.810 2.844 2.890 2.920 2.954 2.982 3.010 3.032 3.060 3.084 3.106 3.120 3.134 3.152 3.166 3.180 3.186 3.194 3.200 3.206
3 1/2" 2.740 2.820 2.900 2.932 2.982 3.024 3.060 3.094 3.140 3.170 3.204 3.232 3.260 3.282 3.310 3.334 3.356 3.370 3.384 3.402 3.416 3.430 3.436 3.444 3.450 3.456
3 3/4" 2.990 3.070 3.150 3.182 3.232 3.274 3.310 3.344 3.390 3.420 3.454 3.482 3.510 3.532 3.560 3.584 3.606 3.620 3.634 3.652 3.666 3.680 3.686 3.694 3.700 3.706
4" 3.240 3.320 3.400 3.432 3.482 3.524 3.560 3.594 3.640 3.670 3.704 3.732 3.760 3.782 3.810 3.834 3.856 3.870 3.884 3.902 3.916 3.930 3.936 3.944 3.950 3.956
4 1/4" 3.490 3.570 3.650 3.682 3.732 3.774 3.810 3.844 3.890 3.920 3.954 3.982 4.010 4.032 4.060 4.084 4.106 4.120 4.134 4.152 4.166 4.180 4.186 4.194 4.200 4.206
4 1/2" 3.740 3.820 3.900 3.932 3.982 4.024 4.060 4.094 4.140 4.170 4.204 4.232 4.260 4.282 4.310 4.334 4.356 4.370 4.384 4.402 4.416 4.430 4.436 4.444 4.450 4.456
4 3/4" 3.990 4.070 4.150 4.182 4.232 4.274 4.310 4.344 4.390 4.420 4.454 4.482 4.510 4.532 4.560 4.584 4.606 4.620 4.634 4.652 4.666 4.680 4.686 4.694 4.700 4.706
5" 4.240 4.320 4.400 4.432 4.482 4.524 4.560 4.594 4.640 4.670 4.704 4.732 4.760 4.782 4.810 4.834 4.856 4.870 4.884 4.902 4.916 4.930 4.936 4.944 4.950 4.956
5 1/4" 4.490 4.570 4.650 4.682 4.732 4.774 4.810 4.844 4.890 4.920 4.954 4.982 5.010 5.032 5.060 5.084 5.106 5.120 5.134 5.152 5.166 5.180 5.186 5.194 5.200 5.20

 

SWG GAUGE (Standard Wire Gauge)

(SWG to inches and millimiters conversion)

SWG 

inches 

mm

 

SWG 

inches 

mm

 

SWG 

inches 

mm

7/0

0.5

12.7

 

13

0.092

2.337

 

32

0.0108

0.274

6/0

0.464

11.786

 

14

0.08

2.032

 

33

0.01

0.254

5/0

0.432

10.973

 

15

0.072

1.829

 

34

0.0092

0.234

4/0

0.4

10.16

 

16

0.064

1.626

 

35

0.0084

0.213

3/0

0.372

9.449

 

17

0.056

1.422

 

36

0.0076

0.193

2/0

0.348

8.839

 

18

0.048

1.219

 

37

0.0068

0.173

1/0

0.324

8.236

 

19

0.04

1.016

 

38

0.006

0.152

1

0.3

7.62

 

20

0.036

0.914

 

39

0.0052

0.132

2

0.276

7.01

 

21

0.032

0.813

 

40

0.0048

0.122

3

0.252

6.401

 

22

0.028

0.711

 

41

0.0044

0.112

4

0.232

5.893

 

23

0.024

0.61

 

42

0.004

0.102

5

0.212

5.385

 

24

0.022

0.559

 

43

0.0036

0.091

6

0.192

4.877

 

25

0.02

0.508

 

44

0.0032

0.081

7

0.176

4.47

 

26

0.018

0.457

 

45

0.0028

0.071

8

0.16

4.064

 

27

0.0164

0.417

 

46

0.0024

0.061

9

0.144

3.658

 

28

0.0148

0.376

 

47

0.002

0.051

10

0.128

3.251

 

29

0.0136

0.345

 

48

0.0016

0.041

11

0.116

2.946

 

30

0.0124

0.315

 

49

0.0012

0.03

12

0.104

2.642

 

31

0.0116

0.295

 

50

0.001

0.025

 Tube BWG vs. SWG.pdf

 

 

 

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