# Birmingham wire gauge (BWG) table: 5/0 to 36 in inches and mm; BWG 14 / 16 / 18 tube wall

> What is the thickness or diameter of BWG (Birmingham wire gauge) 10, 14, 16 and 18, in inches and mm?

- Category: Hardware › Materials & stock
- Kind: Standard part
- Basis: The Engineering ToolBox and Wermac BWG tables (inches agree on all 41 gauges; mm = inches x 25.4)
- Page: https://xemstudio.com/objects/birmingham-wire-gauge-bwg-table/ · JSON: https://xemstudio.com/api/geometry?object=birmingham-wire-gauge-bwg-table · Plain text: https://xemstudio.com/objects/birmingham-wire-gauge-bwg-table/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
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**Exact dimensions.** True size, with no tolerance added.

## Notes

- BWG (Birmingham Wire Gauge, also Stubs' Iron Wire Gauge, B.W.G.): gauge number to thickness. For wire and fine tube the number is the outside diameter; for mechanical and boiler tubing it is the wall thickness whatever the tube's OD. Used for tube wall (BWG 14 = 0.083 in, BWG 16 = 0.065 in, BWG 18 = 0.049 in), hypodermic needle outer diameters (gauge numbers are the same series) and drill rod.
- Inches are from The Engineering ToolBox and Wermac, which agree on every gauge from 5/0 (0.500 in) to 36 (0.004 in). The mm column is inches x 25.4; Wermac's printed mm agree to 0.001 mm (7.214 vs 7.213 for gauge 2 and 0.889 vs 0.888 for gauge 20 are rounding of 0.284 x 25.4 and 0.035 x 25.4).
- BWG is not SWG (British Standard) and not AWG: BWG 10 is 0.134 in, SWG 10 is 0.128 in and AWG 10 is 0.1019 in. See the SWG and AWG pages.
- No standard document was read; the sources name the system, not a BS or ASTM number for the values.

## Sizes

| BWG | inches | mm |
|---|---|---|
| 5/0 | 0.500 | 12.700 |
| 4/0 | 0.454 | 11.532 |
| 3/0 | 0.425 | 10.795 |
| 2/0 | 0.380 | 9.652 |
| 0 | 0.340 | 8.636 |
| 1 | 0.300 | 7.620 |
| 2 | 0.284 | 7.214 |
| 3 | 0.259 | 6.579 |
| 4 | 0.238 | 6.045 |
| 5 | 0.220 | 5.588 |
| 6 | 0.203 | 5.156 |
| 7 | 0.180 | 4.572 |
| 8 | 0.165 | 4.191 |
| 9 | 0.148 | 3.759 |
| 10 | 0.134 | 3.404 |
| 11 | 0.120 | 3.048 |
| 12 | 0.109 | 2.769 |
| 13 | 0.095 | 2.413 |
| 14 | 0.083 | 2.108 |
| 15 | 0.072 | 1.829 |
| 16 | 0.065 | 1.651 |
| 17 | 0.058 | 1.473 |
| 18 | 0.049 | 1.245 |
| 19 | 0.042 | 1.067 |
| 20 | 0.035 | 0.889 |
| 21 | 0.032 | 0.813 |
| 22 | 0.028 | 0.711 |
| 23 | 0.025 | 0.635 |
| 24 | 0.022 | 0.559 |
| 25 | 0.020 | 0.508 |
| 26 | 0.018 | 0.457 |
| 27 | 0.016 | 0.406 |
| 28 | 0.014 | 0.356 |
| 29 | 0.013 | 0.330 |
| 30 | 0.012 | 0.305 |
| 31 | 0.010 | 0.254 |
| 32 | 0.009 | 0.229 |
| 33 | 0.008 | 0.203 |
| 34 | 0.007 | 0.178 |
| 35 | 0.005 | 0.127 |
| 36 | 0.004 | 0.102 |

## Where the files are

- The Engineering ToolBox: [BWG (Birmingham Wire Gauge): gauge, inches](https://www.engineeringtoolbox.com/BWG-wire-gage-d_508.html) — web — Publisher's page; dimensions are facts
- Wermac: [Birmingham wire gauge table: inches and mm](https://www.wermac.org/pipes/birmingham_wire_gauge.html) — web — Publisher's page; dimensions are facts

## Questions

**What is BWG 16 in mm?**

0.065 in = 1.651 mm.

**What is BWG 14 in inches?**

0.083 in (2.108 mm).

**Is BWG the same as SWG?**

No: BWG 10 is 0.134 in, SWG 10 is 0.128 in.

## Fits with

- [SWG standard wire gauge table (British, BS 3737): 7/0 to 50, diameter in inches and mm](https://xemstudio.com/objects/swg-standard-wire-gauge-table/)
- [AWG wire gauge table (ASTM B258): 4/0 to 56 AWG, diameter in mils, inches and mm, area in circular mils and mm²](https://xemstudio.com/objects/awg-wire-gauge-table-astm-b258/)
- [Metric wire sizes (IEC 60228): 0.5 to 2500 mm² with strands and conductor diameter, and the nearest AWG](https://xemstudio.com/objects/metric-wire-sizes-iec-60228-mm2-awg/)
- [Sheet metal gauge chart: steel, galvanized, stainless and aluminum (10, 12, 14, 16, 18, 20 gauge in inches and mm)](https://xemstudio.com/objects/sheet-metal-gauge-chart-steel-galvanized-stainless-aluminum/)
- [Music wire diameters (ASTM A228): .015 to .250 in](https://xemstudio.com/objects/music-wire-sizes/)