Physical and Electrical Properties of Bare Copper Wire

Conductor Size	Wire Diameter	Cross-Sectional Area		CONDUCTOR WEIGHT		HARD-DRAWN		MEDIUM HARD-DRAWN		SOFT OR ANNEALED
Conductor Size	Wire Diameter	Cross-Sectional Area		Per 1000 Feet	Per Mile	Minimum Breaking Strength	D-C Resist. at 20°C	Minimum Breaking Strength	D-C Resist. at 20°C	Maximum Breaking Strength	D-C Resist. at 20°C
AWG	Inches	Circular Mils	Square Inches	Pounds	Pounds	Pounds	Ohms/ M Ft	Pounds	Ohms/ M Ft	Pounds	Ohms/ M Ft
18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 1/0 2/0 3/0 4/0	.04030 .04526 .05082 .05707 .06408 .07196 .08081 .09074 .1019 .1144 .1285 .1443 .1620 .1819 .2043 .2294 .2576 .2893 .3240 .3648 .4096 .4600	1624 2048 2583 3257 4107 5178 6530 8234 10380 13090 16510 20820 26250 33100 41740 52630 66370 83690 105500 133100 167800 211600	.001276 .001609 .002028 .002558 .003225 .004067 .005129 .006467 .008155 .01028 .01297 .01635 .02062 .02600 .03278 .04134 .05213 .06573 .08289 .1045 .1318 .1662	4.917 6.200 7.818 9.858 12.43 15.68 19.77 24.92 31.43 39.63 49.97 63.02 79.46 100.2 126.4 159.3 200.9 253.3 319.5 402.8 507.9 640.5	25.96 32.74 41.28 52.05 65.64 82.77 104.4 131.6 165.9 209.3 263.9 332.7 419.6 529.1 667.1 841.2 1061 1338 1687 2127 2682 3382	85.47 107.5 135.1 169.8 213.5 268.0 336.9 422.9 529.2 661.2 826.0 1030 1280 1591 1970 2439 3003 3688 4517 5519 6722 8143	6.640 5.266 4.176 3.312 2.626 2.083 1.652 1.310 1.039 .8238 .6533 .5181 .4108 .3258 .2584 .2049 .1625 .1289 .1011 .08021 .06361 .05045	67.61 84.71 106.2 133.0 166.6 208.8 261.6 327.6 410.4 514.2 643.9 808.6 1010 1265 1584 1984 2450 3024 3730 4599 5667 6980	6.606 5.239 4.154 3.295 2.613 2.072 1.643 1.303 1.033 .8195 .6499 .5154 .4087 .3241 .2570 .2038 .1617 .1282 .1006 .07980 .06329 .05019	49.12 61.93 78.10 98.48 124.2 156.6 197.5 249.0 314.0 380.5 479.8 605.0 762.9 961.9 1213 1530 1929 2432 2984 3763 4745 5983	6.505 5.158 4.091 3.244 2.573 2.040 1.618 1.283 1.018 .8070 .6400 .5075 .4025 .3192 .2531 .2007 .1592 .1262 .1001 .07939 .06296 .04993

Based on ASTM Standard Specifications B1-40, B2-40, B3-41.

The breaking strengths are based on ASTM specification requirements, using minimum values for hard and medium hard-drawn wire, and maximum values for soft wire.

Temperature Conversion:
   Rt0 = R20 {1+a(T0 -20) } Where
   Rt0 = Resistance at operating temperature (°C), ohms.
   Rt20 = Resistance at 20°C. ohms.
   T0 = Operating temperature, °C.
   a    = 0.00381 = thermal coefficient of resistance for hard-drawn.
            0.00381 = thermal coefficient of resistance for medium hard-drawn.
            0.00386 = thermal coefficient of resistance for soft or annealed.

The resistance values in this table are trade maximums and are higher then the average values for commercial wire. The following values for the conductivity of copper were used


ASTM REQUIREMENTS
x		Conductivity IACS % @ 20°C	Resistively Ohm (mile, pound) @ 20°C
Hard Drawn	-0.325" and larger -0.324" and smaller	97.16 96.16	900.77 910.15
Medium Hard Drawn	-0.325" and larger -0.324" and smaller	97.66 96.66	896.15 905.44
Soft or Annealed	x	98.16	891.58