Nominal Tube Dimensions Chart (BWG)

BWG measures steel tubing sizes, indicating both outside diameter and wall thickness. BWG stands for "Birmingham Wire Gauge" or "Stubs Iron Wire Gauge." Each BWG number corresponds to a specific thickness, convertible to inches or mm.

Outside Diameter
(OD):
BWG Tube Gauge
Thickness:
Tube O.D.
Tube Gauge
BWG 00 BWG 0 BWG 1 BWG 2 BWG 3 BWG 4 BWG 5 BWG 6 BWG 7 BWG 8 BWG 9 BWG 10 BWG 11 BWG 12 BWG 13 BWG 14 BWG 15 BWG 16 BWG 17 BWG 18 BWG 19 BWG 20 BWG 21 BWG 22 BWG 23 BWG 24
Wall Thickness (in)
.380 .340 .300 .284 .259 .238 .220 .203 .180 .165 .148 .134 .120 .109 .095 .083 .072 .065 .058 .049 .042 .035 .032 .028 .025 .022
Tube I.D.
1/4"  N/A  N/A  N/A  N/A  N/A  N/A  N/A  N/A  N/A  N/A  N/A  N/A .010 .032 .060 .084 .106 .120 .134 .152 .166 .180 .186 .194 .200 .206
3/8"  N/A  N/A  N/A  N/A  N/A  N/A  N/A  N/A .015 .045 .079 .107 .135 .157 .185 .209 .231 .245 .259 .277 .291 .305 .311 .319 .325 .331
1/2"  N/A  N/A  N/A  N/A  N/A .024 .060 .094 .140 .170 .204 .232 .260 .282 .310 .334 .356 .370 .384 .402 .416 .430 .436 .444 .450 .456
5/8"  N/A  N/A .025 .057 .107 .149 .185 .219 .265 .295 .329 .357 .385 .407 .435 .459 .481 .495 .509 .527 .541 .555 .561 .569 .575 .581
3/4"  N/A .070 .150 .182 .232 .274 .310 .344 .390 .420 .454 .482 .510 .532 .560 .584 .606 .620 .634 .652 .666 .680 .686 .694 .700 .706
7/8" .115 .195 .275 .307 .357 .399 .435 .469 .515 .545 .579 .607 .635 .657 .685 .709 .731 .745 .759 .777 .791 .805 .811 .819 .825 .831
1" .240 .320 .400 .432 .482 .524 .560 .594 .640 .670 .704 .732 .760 .782 .810 .834 .856 .870 .884 .902 .916 .930 .936 .944 .950 .956
1 1/8" .365 .445 .525 .557 .607 .649 .685 .719 .765 .795 .829 .857 .885 .907 .935 .959 .981 .995 1.009 1.027 1.041 1.055 1.061 1.069 1.075 1.081
1 1/4" .490 .570 .650 .682 .732 .774 .810 .844 .890 .920 .954 .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" .740 .820 .900 .932 .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" .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 5.206