查看“︁美国线规”︁的源代码

[[File:Wire gauge (PSF).png|thumb|圆形线规尺。]]
'''美国线规'''（{{lang-en|American wire gauge}}），缩写为'''AWG'''，是一种区分[[導線|导线]][[直径]]的标准，又被称为'''{{le|Brown & Sharpe|Brown & Sharpe}}线规'''。这种[[标准化]]线规系统于1857年起在[[美国]]开始使用。<ref>ASTM Standard B 258-02, ''Standard specification for standard nominal diameters and cross-sectional areas of AWG sizes of solid round wires used as electrical conductors'', [[ASTM]] International, 2002 </ref>

钢铁工业使用不同的线规，所以下述内容并不适用于钢丝。

==簡介==
數字代表相同面積下，能塞進的AWG線數目。线规数字越小，表示线材直径越粗，所能承载的电流就越大；反之，线规数字越大，表示线材直径越细，所能承载的电流就越小。

AWG表适用于单根、实心、圆形的导线。[[双绞线]]的AWG值由所有导线的总横截面积决定，并且由于双绞线之间总是有一些空隙，导致相同的AWG值双绞线的直径总是略大于单根导线的直径。

AWG数值应作为基本数值标注于数据线上。例如，组网使用的[[CAT-5|五类]][[非屏蔽双绞线]]一般使用AWG 24的线材，而[[SATA]]线一般是AWG 26线材。

英國和美國使用線號標記法。線號又稱線規（{{lang|en|wire gauge}}），按0、 1、 2、 3……數碼順序表示，數碼越大，線材越細。300年前，軋製和擠壓尚未誕生，還是用鍛造製備線坯。當年的測量工具也很粗糙，在這情況下以拉制的次數作為線材粗細的標誌。每拉一次增加一號，線坯則為0號。因為有眾多作坊，其工藝又各不相同，於是出現了眾多的線號標準。經過300年的淘汰、兼併和變遷，有的國家就改為直徑計量，但線號標記法於英國和美國就沿用至今。現今常使用的是美國線規（AWG）、伯明罕線規（BWG）和英帝國標準線規（SWG）。

==计算公式==
定义直径0.005英寸为AWG 36，直径0.46英寸为AWG 0000。从AWG 36至AWG 0000等比共计40个值。可以根据如下公式计算出每种AWG值的实际直径：

:<math>D_n = 0.005~\mathrm{inch} \times 92 ^ \frac{36-n}{39}</math>
或者
:<math>D_n = 0.005~\mathrm{mm} \times 25.4 \times 92 ^ \frac{36-n}{39}</math>
n代表AWG的值。

横截面积为：

:<math>A_n = \frac{\pi}{4} D_n^2 = 0.000019635~\mathrm{inch}^2 \times 92 ^ \frac{36-n}{19.5}</math>.

从直径计算AWG值可以通过如下公式：

:<math>n=-39\log_{92} \left( \frac{D_{n}}{0.005~\mathrm{inch}} \right)+36</math>   <ref>The logarithm to the base 92 can be computed using any other logarithm, such as [[Common logarithm|common]] or [[natural logarithm]], using log<sub>92</sub>''x'' = (log ''x'')/(log 92).</ref>

AWG 00，AWG 000，AWG 0000的n分别使用-1，-2，-3。

==AWG尺寸对照表==
　
表格中的数据包括各种导线的[[阻抗]]和允许电流大小（安培）。表中的直径数值适用于实心电线。双绞线应当根据铜线[[横截面]][[面积]]进行计算。下面的表格适用于直流情况，或者[[頻率 (物理學)|频率]]小于等于60[[赫兹]]的情况，也没有考虑[[集肤效应]]。
　
{| class="wikitable" style="textalign:center;"
! rowspan="4" |AWG
! colspan="2" rowspan="3" |直徑
! colspan="2" rowspan="3" |直徑之倒數(無絕緣時，
單位長度可排下之線數)
(說明1)
! colspan="2" rowspan="3" |截面積
! colspan="8" |銅線
|-
! colspan="2" rowspan="2" |銅[[電阻|阻抗]]
! colspan="3" |用不同額定溫度的絕緣物質，在室溫 20℃ 下之[[ampacity|載流量]] (容許電流)，
16 AWG 及以下指設備中的單線(未集束):
! colspan="3" |熔斷電流(說明2)
|-
!60&nbsp;°C
!75&nbsp;°C
!90&nbsp;°C
!Preece
! colspan="2" |Onderdonk
|-
!(in)
!(mm)
!(per&nbsp;in)
!(per&nbsp;cm)
!([[圓密耳|kcmil]])
!(mm<sup>2</sup>)
!(mΩ/m)
!(mΩ/ft)
! colspan="3" |(A)
!~10 s
!1 s
!32&nbsp;ms
|-
|0000 (4/0)
|0.4600{{efn|定義的確切數值。|name=def}}
|11.684{{efn|name=def}}
|2.17
|0.856
|212
|107
|0.1608
|0.04901
|195
|230
|260
|3.2 kA
|33 kA
|182 kA
|-
|000 (3/0)
|0.4096
|10.405
|2.44
|0.961
|168
|85.0
|0.2028
|0.06180
|165
|200
|225
|2.7 kA
|26 kA
|144 kA
|-
|00 (2/0)
|0.3648
|9.266
|2.74
|1.08
|133
|67.4
|0.2557
|0.07793
|145
|175
|195
|2.3 kA
|21 kA
|115 kA
|-
|0 (1/0)
|0.3249
|8.251
|3.08
|1.21
|106
|53.5
|0.3224
|0.09827
|125
|150
|170
|1.9 kA
|16 kA
|91 kA
|-
|1
|0.2893
|7.348
|3.46
|1.36
|83.7
|42.4
|0.4066
|0.1239
|110
|130
|145
|1.6 kA
|13 kA
|72 kA
|-
|2
|0.2576
|6.544
|3.88
|1.53
|66.4
|33.6
|0.5127
|0.1563
|95
|115
|130
|1.3 kA
|10.2 kA
|57 kA
|-
|3
|0.2294
|5.827
|4.36
|1.72
|52.6
|26.7
|0.6465
|0.1970
|85
|100
|115
|1.1 kA
|8.1 kA
|45 kA
|-
|4
|0.2043
|5.189
|4.89
|1.93
|41.7
|21.2
|0.8152
|0.2485
|70
|85
|95
|946 A
|6.4 kA
|36 kA
|-
|5
|0.1819
|4.621
|5.50
|2.16
|33.1
|16.8
|1.028
|0.3133
| colspan="3" |
|795 A
|5.1 kA
|28 kA
|-
|6
|0.1620
|4.115
|6.17
|2.43
|26.3
|13.3
|1.296
|0.3951
|55
|65
|75
|668 A
|4.0 kA
|23 kA
|-
|7
|0.1443
|3.665
|6.93
|2.73
|20.8
|10.5
|1.634
|0.4982
| colspan="3" |
|561 A
|3.2 kA
|18 kA
|-
|8
|0.1285
|3.264
|7.78
|3.06
|16.5
|8.37
|2.061
|0.6282
|40
|50
|55
|472 A
|2.5 kA
|14 kA
|-
|9
|0.1144
|2.906
|8.74
|3.44
|13.1
|6.63
|2.599
|0.7921
| colspan="3" |
|396 A
|2.0 kA
|11 kA
|-
|10
|0.1019
|2.588
|9.81
|3.86
|10.4
|5.26
|3.277
|0.9989
|30
|35
|40
|333 A
|1.6 kA
|8.9 kA
|-
|11
|0.0907
|2.305
|11.0
|4.34
|8.23
|4.17
|4.132
|1.260
| colspan="3" |
|280 A
|1.3 kA
|7.1 kA
|-
|12
|0.0808
|2.053
|12.4
|4.87
|6.53
|3.31
|5.211
|1.588
|20
|25
|30
|235 A
|1.0 kA
|5.6 kA
|-
|13
|0.0720
|1.828
|13.9
|5.47
|5.18
|2.62
|6.571
|2.003
| colspan="3" |
|198 A
|798 A
|4.5 kA
|-
|14
|0.0641
|1.628
|15.6
|6.14
|4.11
|2.08
|8.286
|2.525
|15
|20
|25
|166 A
|633 A
|3.5 kA
|-
|15
|0.0571
|1.450
|17.5
|6.90
|3.26
|1.65
|10.45
|3.184
| colspan="3" |
|140 A
|502 A
|2.8 kA
|-
|16
|0.0508
|1.291
|19.7
|7.75
|2.58
|1.31
|13.17
|4.016
|22*流通空氣
|13*密閉
|18
|117 A
|398 A
|2.2 kA
|-
|17
|0.0453
|1.150
|22.1
|8.70
|2.05
|1.04
|16.61
|5.064
| colspan="3" |
|99 A
|316 A
|1.8 kA
|-
|18
|0.0403
|1.024
|24.8
|9.77
|1.62
|0.823
|20.95
|6.385
|10
|14
|16
|83 A
|250 A
|1.4 kA
|-
|19
|0.0359
|0.912
|27.9
|11.0
|1.29
|0.653
|26.42
|8.051
|—
|—
|—
|70 A
|198 A
|1.1 kA
|-
|20
|0.0320
|0.812
|31.3
|12.3
|1.02
|0.518
|33.31
|10.15
|5
|11
|—
|58.5 A
|158 A
|882 A
|-
|21
|0.0285
|0.723
|35.1
|13.8
|0.810
|0.410
|42.00
|12.80
|—
|—
|—
|49 A
|125 A
|700 A
|-
|22
|0.0253
|0.644
|39.5
|15.5
|0.642
|0.326
|52.96
|16.14
|3
|7
|—
|41 A
|99 A
|551 A
|-
|23
|0.0226
|0.573
|44.3
|17.4
|0.509
|0.258
|66.79
|20.36
|—
|—
|—
|35 A
|79 A
|440 A
|-
|24
|0.0201
|0.511
|49.7
|19.6
|0.404
|0.205
|84.22
|25.67
|2.1
|3.5
|—
|29 A
|62 A
|348 A
|-
|25
|0.0179
|0.455
|55.9
|22.0
|0.320
|0.162
|106.2
|32.37
|—
|—
|—
|24 A
|49 A
|276 A
|-
|26
|0.0159
|0.405
|62.7
|24.7
|0.254
|0.129
|133.9
|40.81
|1.3
|2.2
|—
|20 A
|39 A
|218 A
|-
|27
|0.0142
|0.361
|70.4
|27.7
|0.202
|0.102
|168.9
|51.47
|—
|—
|—
|17 A
|31 A
|174 A
|-
|28
|0.0126
|0.321
|79.1
|31.1
|0.160
|0.0810
|212.9
|64.90
|0.83
|1.4
|—
|14 A
|24 A
|137 A
|-
|29
|0.0113
|0.286
|88.8
|35.0
|0.127
|0.0642
|268.5
|81.84
|—
|—
|—
|12 A
|20 A
|110 A
|-
|30
|0.0100
|0.255
|99.7
|39.3
|0.101
|0.0509
|338.6
|103.2
|0.52
|0.86
|—
|10 A
|15 A
|86 A
|-
|31
|0.00893
|0.227
|112
|44.1
|0.0797
|0.0404
|426.9
|130.1
|—
|—
|—
|9 A
|12 A
|69 A
|-
|32
|0.00795
|0.202
|126
|49.5
|0.0632
|0.0320
|538.3
|164.1
|0.32
|0.53
|—
|7 A
|10 A
|54 A
|-
|33
|0.00708
|0.180
|141
|55.6
|0.0501
|0.0254
|678.8
|206.9
|—
|—
|—
|6 A
|7.7 A
|43 A
|-
|34
|0.00630
|0.160
|159
|62.4
|0.0398
|0.0201
|856.0
|260.9
|0.18
|0.3
|—
|5 A
|6.1 A
|34 A
|-
|35
|0.00561
|0.143
|178
|70.1
|0.0315
|0.0160
|1079
|329.0
|—
|—
|—
|4 A
|4.8 A
|27 A
|-
|36
|0.00500
|0.127{{efn|name=def}}
|200{{efn|name=def}}
|78.7
|0.0250
|0.0127
|1361
|414.8
|—
|—
|—
|4 A
|3.9 A
|22 A
|-
|37
|0.00445
|0.113
|225
|88.4
|0.0198
|0.0100
|1716
|523.1
|—
|—
|—
|3 A
|3.1 A
|17 A
|-
|38
|0.00397
|0.101
|252
|99.3
|0.0157
|0.00797
|2164
|659.6
|—
|—
|—
|3 A
|2.4 A
|14 A
|-
|39
|0.00353
|0.0897
|283
|111
|0.0125
|0.00632
|2729
|831.8
|—
|—
|—
|2 A
|1.9 A
|11 A
|-
|40
|0.00314
|0.0799
|318
|125
|0.00989
|0.00501
|3441
|1049
|—
|—
|—
|1 A
|1.5 A
|8.5 A
|}

說明1：本欄僅供參考，因為實際繞製線圈時須使用有絕緣包覆之漆包線，絕緣層厚度需加入考慮。

說明2：依據 Standard Handbook for Electrical Engineers 第4-25頁(第15版或16版)提到的兩種公式計算而得 {{Citation |title=Standard Handbook for Electrical Engineers |edition=15th |date=2007 |editor1-first=H. Wayne |editor-last=Beaty |editor2-first=Donald G. |editor2-last=Fink |publisher=McGraw Hill |page=4–25 |isbn=978-0-07-144146-9}}

說明3：线规与载流量以及趋肤效应的关系：http://www.powerstream.com/Wire_Size.htm {{Wayback|url=http://www.powerstream.com/Wire_Size.htm |date=20121010053050 }}

==参见==
*[[IEC 60228]]国际线材尺寸标准
*[[英国线规]]
* 

==注释==
{{notelist}}

==參考資料==
<div class="references-small">
<references />
</div>

[[Category:度量儀器]]
[[Category:美國度量衡單位]]