Soild copper wire table:
Size Diameter Cross-sectional area Weight AWG inches cir. mils sq. inches lb/1000 ft ================================================================ 4/0 -------- 0.4600 ------- 211,600 ------ 0.1662 ------ 640.5 3/0 -------- 0.4096 ------- 167,800 ------ 0.1318 ------ 507.9 2/0 -------- 0.3648 ------- 133,100 ------ 0.1045 ------ 402.8 1/0 -------- 0.3249 ------- 105,500 ----- 0.08289 ------ 319.5 1 ---------- 0.2893 ------- 83,690 ------ 0.06573 ------ 253.5 2 ---------- 0.2576 ------- 66,370 ------ 0.05213 ------ 200.9 3 ---------- 0.2294 ------- 52,630 ------ 0.04134 ------ 159.3 4 ---------- 0.2043 ------- 41,740 ------ 0.03278 ------ 126.4 5 ---------- 0.1819 ------- 33,100 ------ 0.02600 ------ 100.2 6 ---------- 0.1620 ------- 26,250 ------ 0.02062 ------ 79.46 7 ---------- 0.1443 ------- 20,820 ------ 0.01635 ------ 63.02 8 ---------- 0.1285 ------- 16,510 ------ 0.01297 ------ 49.97 9 ---------- 0.1144 ------- 13,090 ------ 0.01028 ------ 39.63 10 --------- 0.1019 ------- 10,380 ------ 0.008155 ----- 31.43 11 --------- 0.09074 ------- 8,234 ------ 0.006467 ----- 24.92 12 --------- 0.08081 ------- 6,530 ------ 0.005129 ----- 19.77 13 --------- 0.07196 ------- 5,178 ------ 0.004067 ----- 15.68 14 --------- 0.06408 ------- 4,107 ------ 0.003225 ----- 12.43 15 --------- 0.05707 ------- 3,257 ------ 0.002558 ----- 9.858 16 --------- 0.05082 ------- 2,583 ------ 0.002028 ----- 7.818 17 --------- 0.04526 ------- 2,048 ------ 0.001609 ----- 6.200 18 --------- 0.04030 ------- 1,624 ------ 0.001276 ----- 4.917 19 --------- 0.03589 ------- 1,288 ------ 0.001012 ----- 3.899 20 --------- 0.03196 ------- 1,022 ----- 0.0008023 ----- 3.092 21 --------- 0.02846 ------- 810.1 ----- 0.0006363 ----- 2.452 22 --------- 0.02535 ------- 642.5 ----- 0.0005046 ----- 1.945 23 --------- 0.02257 ------- 509.5 ----- 0.0004001 ----- 1.542 24 --------- 0.02010 ------- 404.0 ----- 0.0003173 ----- 1.233 25 --------- 0.01790 ------- 320.4 ----- 0.0002517 ----- 0.9699 26 --------- 0.01594 ------- 254.1 ----- 0.0001996 ----- 0.7692 27 --------- 0.01420 ------- 201.5 ----- 0.0001583 ----- 0.6100 28 --------- 0.01264 ------- 159.8 ----- 0.0001255 ----- 0.4837 29 --------- 0.01126 ------- 126.7 ----- 0.00009954 ---- 0.3836 30 --------- 0.01003 ------- 100.5 ----- 0.00007894 ---- 0.3042 31 -------- 0.008928 ------- 79.70 ----- 0.00006260 ---- 0.2413 32 -------- 0.007950 ------- 63.21 ----- 0.00004964 ---- 0.1913 33 -------- 0.007080 ------- 50.13 ----- 0.00003937 ---- 0.1517 34 -------- 0.006305 ------- 39.75 ----- 0.00003122 ---- 0.1203 35 -------- 0.005615 ------- 31.52 ----- 0.00002476 --- 0.09542 36 -------- 0.005000 ------- 25.00 ----- 0.00001963 --- 0.07567 37 -------- 0.004453 ------- 19.83 ----- 0.00001557 --- 0.06001 38 -------- 0.003965 ------- 15.72 ----- 0.00001235 --- 0.04759 39 -------- 0.003531 ------- 12.47 ---- 0.000009793 --- 0.03774 40 -------- 0.003145 ------- 9.888 ---- 0.000007766 --- 0.02993 41 -------- 0.002800 ------- 7.842 ---- 0.000006159 --- 0.02374 42 -------- 0.002494 ------- 6.219 ---- 0.000004884 --- 0.01882 43 -------- 0.002221 ------- 4.932 ---- 0.000003873 --- 0.01493 44 -------- 0.001978 ------- 3.911 ---- 0.000003072 --- 0.01184
Ampacities of copper wire, in free air at 30o C:
======================================================== | INSULATION TYPE: | | RUW, T THW, THWN FEP, FEPB | | TW RUH THHN, XHHW | ======================================================== Size Current Rating Current Rating Current Rating AWG @ 60 degrees C @ 75 degrees C @ 90 degrees C ======================================================== 20 -------- *9 ----------------------------- *12.5 18 -------- *13 ------------------------------ 18 16 -------- *18 ------------------------------ 24 14 --------- 25 ------------- 30 ------------- 35 12 --------- 30 ------------- 35 ------------- 40 10 --------- 40 ------------- 50 ------------- 55 8 ---------- 60 ------------- 70 ------------- 80 6 ---------- 80 ------------- 95 ------------ 105 4 --------- 105 ------------ 125 ------------ 140 2 --------- 140 ------------ 170 ------------ 190 1 --------- 165 ------------ 195 ------------ 220 1/0 ------- 195 ------------ 230 ------------ 260 2/0 ------- 225 ------------ 265 ------------ 300 3/0 ------- 260 ------------ 310 ------------ 350 4/0 ------- 300 ------------ 360 ------------ 405
* = estimated values; normally, wire gages this small are not manufactured with these insulation types.
Specific resistance at 20o C:
Material Element/Alloy (ohm-cmil/ft) (ohm-cm) ==================================================================== Nichrome ------- Alloy ---------------- 675 ------------- 112.2-6 Nichrome V ----- Alloy ---------------- 650 ------------- 108.1-6 Manganin ------- Alloy ---------------- 290 ------------- 48.21-6 Constantan ----- Alloy ---------------- 272.97 ---------- 45.38-6 Steel* --------- Alloy ---------------- 100 ------------- 16.62-6 Platinum ------ Element --------------- 63.16 ----------- 10.5-6 Iron ---------- Element --------------- 57.81 ----------- 9.61-6 Nickel -------- Element --------------- 41.69 ----------- 6.93-6 Zinc ---------- Element --------------- 35.49 ----------- 5.90-6 Molybdenum ---- Element --------------- 32.12 ----------- 5.34-6 Tungsten ------ Element --------------- 31.76 ----------- 5.28-6 Aluminum ------ Element --------------- 15.94 ----------- 2.650-6 Gold ---------- Element --------------- 13.32 ----------- 2.214-6 Copper -------- Element --------------- 10.09 ----------- 1.678-6 Silver -------- Element --------------- 9.546 ----------- 1.587-6
* = Steel alloy at 99.5 percent iron, 0.5 percent carbon.
Temperature coefficient (α) per degree C:
Material Element/Alloy Temp. coefficient ===================================================== Nickel -------- Element --------------- 0.005866 Iron ---------- Element --------------- 0.005671 Molybdenum ---- Element --------------- 0.004579 Tungsten ------ Element --------------- 0.004403 Aluminum ------ Element --------------- 0.004308 Copper -------- Element --------------- 0.004041 Silver -------- Element --------------- 0.003819 Platinum ------ Element --------------- 0.003729 Gold ---------- Element --------------- 0.003715 Zinc ---------- Element --------------- 0.003847 Steel* --------- Alloy ---------------- 0.003 Nichrome ------- Alloy ---------------- 0.00017 Nichrome V ----- Alloy ---------------- 0.00013 Manganin ------- Alloy ------------ +/- 0.000015 Constantan ----- Alloy --------------- -0.000074
* = Steel alloy at 99.5 percent iron, 0.5 percent carbon
Critical temperatures given in Kelvins
Material Element/Alloy Critical temperature(K) ====================================================== Aluminum -------- Element --------------- 1.20 Cadmium --------- Element --------------- 0.56 Lead ------------ Element --------------- 7.2 Mercury --------- Element --------------- 4.16 Niobium --------- Element --------------- 8.70 Thorium --------- Element --------------- 1.37 Tin ------------- Element --------------- 3.72 Titanium -------- Element --------------- 0.39 Uranium --------- ELement --------------- 1.0 Zinc ------------ Element --------------- 0.91 Niobium/Tin ------ Alloy ---------------- 18.1 Cupric sulphide - Compound -------------- 1.6
Note: all critical temperatures given at zero magnetic field strength.
Dielectric strength in kilovolts per inch (kV/in):
Material* Dielectric strength ========================================= Vacuum --------------------- 20 Air ------------------------ 20 to 75 Porcelain ------------------ 40 to 200 Paraffin Wax --------------- 200 to 300 Transformer Oil ------------ 400 Bakelite ------------------- 300 to 550 Rubber --------------------- 450 to 700 Shellac -------------------- 900 Paper ---------------------- 1250 Teflon --------------------- 1500 Glass ---------------------- 2000 to 3000 Mica ----------------------- 5000
* = Materials listed are specially prepared for electrical use
Tables of specific resistance and temperature coefficient of resistance for elemental materials (not alloys) were derived from figures found in the 78th edition of the CRC Handbook of Chemistry and Physics. Superconductivity data from Collier's Encyclopedia (volume 21, 1968, page 640).
Lessons In Electric Circuits copyright (C) 2000-2006 Tony R. Kuphaldt, under the terms and conditions of the Design Science License.