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AWG NEMA / IEC Metric Standard Size Chart
- Bare Wire Dimensions -
AWG (American Wire Gauge)
AWG numbers follow a mathematical formulation devised by Brown and Sharpe in 1855. The AWG designation corresponds to the number of steps by which the wire is drawn. (18 AWG is smaller than 10 AWG, therefore is drawn more times to obtain a smaller cross sectional area.) According to the "Standard Handbook for Electrical Engineers" (Fink and Beaty) 'gauge' is the American Wire Gauge also known as the Brown & Sharpe gauge, which is the standard for which American engineers adhere.
AWG began at 4/0 wire with a diameter of 0.46" and the next lower wire size was derived by multiplying the diameter by 0.890526. These then became tabulated into what we today call the AWG; ranging down to 40 gauge wire at 0.003" in diameter. The primary concern in a mechanical standard is for electrical conductors and current carrying capacity (driven by resistance).
To product engineers from lawsuits and physical harm a resistance measurement system was implemented to certify that all wire produced in the United States met the DC resistance specifications. The process of measuring the DC resistance is known as the 2-terminal method.
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AWG
SIZE
|
NEMA
Nominal Diameter
Inches / MM |
IEC R-20
Series MM
|
AWG
SIZE
|
NEMA
Nominal Diameter
Inches / MM |
IEC R-20
Series MM
|
4/0 |
0.4600 |
11.684 |
- |
27 |
0.0142 |
0.361 |
0.355 |
3/0 |
0.4096 |
10.404 |
- |
28 |
0.0126 |
0.320 |
0.315 |
2/0 |
0.3648 |
9.266 |
- |
29 |
0.0113 |
0.287 |
0.280 |
1/0 |
0.3249 |
8.252 |
- |
30 |
0.0100 |
0.254 |
0.250 |
1 |
0.2893 |
7.348 |
- |
31 |
0.0089 |
0.226 |
0.224 |
2 |
0.2576 |
6.543 |
- |
32 |
0.0080 |
0.203 |
0.200 |
3 |
0.2294 |
5.827 |
- |
33 |
0.0071 |
0.180 |
0.180 |
4 |
0.2043 |
5.189 |
5.000 |
34 |
0.0063 |
0.160 |
0.160 |
5 |
0.1819 |
4.620 |
4.500 |
35 |
0.0056 |
0.142 |
0.140 |
6 |
0.1620 |
4.115 |
4.000 |
36 |
0.0050 |
0.127 |
0.125 |
7 |
0.1443 |
3.665 |
3.550 |
37 |
0.0045 |
0.114 |
0.112 |
8 |
0.1285 |
3.264 |
3.150 |
38 |
0.0040 |
0.102 |
0.100 |
9 |
0.1144 |
2.906 |
2.800 |
39 |
0.0035 |
0.089 |
0.090 |
10 |
0.1019 |
2.588 |
2.500 |
40 |
0.0031 |
0.079 |
0.080 |
11 |
0.0907 |
2.304 |
2.240 |
41 |
0.0028 |
0.071 |
0.071 |
12 |
0.0808 |
2.052 |
2.000 |
42 |
0.0025 |
0.064 |
0.063 |
13 |
0.0720 |
1.829 |
1.800 |
43 |
0.0022 |
0.056 |
0.056 |
14 |
0.0641 |
1.628 |
1.600 |
44 |
0.0020 |
0.051 |
0.050 |
15 |
0.0571 |
1.450 |
1.400 |
45 |
0.00176 |
0.0447 |
0.045 |
16 |
0.0508 |
1.290 |
1.250 |
46 |
0.00157 |
0.0399 |
0.040 |
17 |
0.0453 |
1.151 |
1.120 |
47 |
0.00140 |
0.0356 |
0.035 |
18 |
0.0403 |
1.024 |
1.000 |
48 |
0.00124 |
0.0315 |
0.031 |
19 |
0.0359 |
0.912 |
0.900 |
49 |
0.00111 |
0.0282 |
0.028 |
20 |
0.0320 |
0.813 |
0.800 |
50 |
0.00099 |
0.0251 |
0.025 |
21 |
0.0285 |
0.724 |
0.710 |
51 |
0.00088 |
0.0224 |
0.022 |
22 |
0.0253 |
0.643 |
0.630 |
52 |
0.00078 |
0.0198 |
0.020 |
23 |
0.0226 |
0.574 |
0.560 |
53 |
0.00070 |
0.0178 |
0.0187 |
24 |
0.0201 |
0.511 |
0.500 |
54 |
0.00062 |
0.0157 |
0.0157 |
25 |
0.0179 |
0.455 |
0.450 |
55 |
0.00055 |
0.0140 |
0.0140 |
26 |
0.0159 |
0.404 |
0.400 |
56 |
0.00049 |
0.0124 |
0.0124 |
AWG
SIZE
|
NEMA
Nominal Diameter
Inches / MM |
IEC R-20
Series MM
|
AWG
SIZE
|
NEMA
Nominal Diameter
Inches / MM |
IEC R-20
Series MM
|
|
|
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* Information to be used as guide only. *
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