Livingston Jewelers

Your Traditional Jeweler for the Future.

Determining Metal Gauges


Sheet metal gauge is a measure of thickness where larger numbers = thinner metal.

That being siad. . .
These charts are a crucial tool for jewelers wanting to accurately convert from inches or millimeters to the equivalent gauge when purchasing and using round wire or flat sheet.

But I suggest that instead of using gauge, you follow the ASTM's suggestion and go with thickness measured in inches or millimeters instead:
"The use of gauge number is discouraged as being an archaic term of limited usefulness not having general agreement on meaning." (Specification ASTM A480-10a)

I highly recommend that you print a copy of this for your bench and your computer. This way you are always one glance away from knowing the gauge you want when you are hard at work on a piece of jewelry.


Brown and Sharpe Gauge to Inches to Millimeters Conversion Table

Brown and Sharpe Gauge to Inches to Millimeters Conversion Table
B & S Gauge Inch (Decimal) Millimeter (mm) Inch (Fraction)
1 0.289 7.348 .
2 0.258 6.543 .
. 0.250 6.350 1/4
. 0.234 5.953 15/64
3 0.229 5.827 .
. 0.219 5.556 7/32
4 0.204 5.189 .
. 0.203 5.154 13/64
. 0.188 4.762 3/16
5 0.182 4.621 .
. 0.172 4.366 11/64
6 0.162 4.115 .
. 0.156 3.969 5/32
7 0.144 3.664 .
. 0.141 3.572 9/64
8 0.128 3.263 .
. 0.125 3.175 1/8
9 0.114 2.906 .
. 0.109 2.778 7/64
10 0.102 2.588 .
. 0.094 2.381 3/32
11 0.091 2.304 .
12 0.081 2.052 .
. 0.078 1.984 5/64
13 0.072 1.828 .
14 0.064 1.628 .
. 0.063 1.588 1/16
15 0.057 1.449 .
16 0.051 1.291 .
. 0.047 1.191 3/64
17 0.045 1.149 .
18 0.040 1.024 .
19 0.036 0.912 .
20 0.032 0.812 .
. 0.031 0.795 1/32
21 0.028 0.723 .
22 0.025 0.644 .
23 0.023 0.573 .
24 0.020 0.511 .
25 0.018 0.455 .
26 0.016 0.405 .
. 0.016 0.396 1/64
27 0.014 0.360 .
28 0.013 0.321 .
29 0.011 0.286 .
30 0.010 0.255 .
31 0.0089 0.226 .
32 0.0080 0.200 .
33 0.0071 0.180 .
34 0.0063 0.160 .
35 0.0056 0.142 .
36 0.0050 0.130 .
37 0.0045 0.114 .
38 0.0040 0.100 .



The American wire gauge (AWG) standards for wire

This table is for a single, solid, round wire.

AWG is also commonly used to specify body piercing jewelry sizes (especially smaller sizes), even when the material is not metallic.

Increasing gauge numbers denote decreasing wire diameters, which is similar to many other non-metric gauging systems such as SWG. This gauge system originated in the number of drawing operations used to produce a given gauge of wire. Very fine wire (for example, 30 gauge) required more passes through the drawing dies than 0 gauge wire did.


The American wire gauge (AWG) standards for wire
AWG # Diameter
(inch)
Diameter
(mm)
Area
(kcmil)
Area
(mm2)
0000 (4/0) 0.4600 11.6840 211.6000 107.2193
000 (3/0) 0.4096 10.4049 167.8064 85.0288
00 (2/0) 0.3648 9.2658 133.0765 67.4309
0 (1/0) 0.3249 8.2515 105.5345 53.4751
1 0.2893 7.3481 83.6927 42.4077
2 0.2576 6.5437 66.3713 33.6308
3 0.2294 5.8273 52.6348 26.6705
4 0.2043 5.1894 41.7413 21.1506
5 0.1819 4.6213 33.1024 16.7732
6 0.1620 4.1154 26.2514 13.3018
7 0.1443 3.6649 20.8183 10.5488
8 0.1285 3.2636 16.5097 8.3656
9 0.1144 2.9064 13.0927 6.6342
10 0.1019 2.5882 10.3830 5.2612
11 0.0907 2.3048 8.2341 4.1723
12 0.0808 2.0525 6.5299 3.3088
13 0.0720 1.8278 5.1785 2.6240
14 0.0641 1.6277 4.1067 2.0809
15 0.0571 1.4495 3.2568 1.6502
16 0.0508 1.2908 2.5827 1.3087
17 0.0453 1.1495 2.0482 1.0378
18 0.0403 1.0237 1.6243 0.8230
19 0.0359 0.9116 1.2881 0.6527
20 0.0320 0.8118 1.0215 0.5176
21 0.0285 0.7229 0.8101 0.4105
22 0.0253 0.6438 0.6424 0.3255
23 0.0226 0.5733 0.5095 0.2582
24 0.0201 0.5106 0.4040 0.2047
25 0.0179 0.4547 0.3204 0.1624
26 0.0159 0.4049 0.2541 0.1288
27 0.0142 0.3606 0.2015 0.1021
28 0.0126 0.3211 0.1598 0.0810
29 0.0113 0.2859 0.1267 0.0642
30 0.0100 0.2546 0.1005 0.0509
31 0.0089 0.2268 0.0797 0.0404
32 0.0080 0.2019 0.0632 0.0320
33 0.0071 0.1798 0.0501 0.0254
34 0.0063 0.1601 0.0398 0.0201
35 0.0056 0.1426 0.0315 0.0160
36 0.0050 0.1270 0.0250 0.0127
37 0.0045 0.1131 0.0198 0.0100
38 0.0040 0.1007 0.0157 0.0080
39 0.0035 0.0897 0.0125 0.0063
40 0.0031 0.0799 0.0099 0.0050

Below is some information about Brown & Sharpe from Wikkipedia,

During the 19th and 20th centuries, Brown & Sharpe was one of the best-known and most influential machine tool builders and was a leading manufacturer of instruments for machinists (such as micrometers and indicators). Its reputation and influence were such that its name is often considered to be inseparably paired with certain industrial standards that it helped establish, including:

  • The American wire gauge (AWG) standards for wire;
  • The Brown & Sharpe taper in machine tool spindle tapers; and
  • The Brown & Sharpe worm threadform for worm gears.

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