Birmingham wire gauge (BWG) table: 5/0 to 36 in inches and mm; BWG 14 / 16 / 18 tube wall — dimension sheet Source: Xem Studio, https://xemstudio.com/objects/birmingham-wire-gauge-bwg-table/ (sheet CC BY 4.0) Basis: The Engineering ToolBox and Wermac BWG tables (inches agree on all 41 gauges; mm = inches x 25.4) Catalog version: 2026-10-20 Sizes: see table below - 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. 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 Files elsewhere (not hosted by Xem Studio; license as stated by the publisher): - The Engineering ToolBox: BWG (Birmingham Wire Gauge): gauge, inches — web — Publisher's page; dimensions are facts — https://www.engineeringtoolbox.com/BWG-wire-gage-d_508.html - Wermac: Birmingham wire gauge table: inches and mm — web — Publisher's page; dimensions are facts — https://www.wermac.org/pipes/birmingham_wire_gauge.html No true-size file yet: the published figures do not fix the whole shape; a measured scan is planned. API: https://xemstudio.com/api/geometry?object=birmingham-wire-gauge-bwg-table