For the purpose of securing uniformity the following is established as the only standard gauge for sheet and plate iron and steel in the United States of America, namely: Number of gauge Approximate thickness in fractions of an inch Approximate thickness in decimal parts of an inch Approximate thickness in millimeters Weight per square foot in ounces avoirdupois Weight per square foot in pounds avoirdupois Weight per square foot in kilograms Weight per square meter in kilograms Weight per square meter in pounds avoirdupois 0000000 1/2 .5 12.7 320 20.00 9.072 97.65 215.28 000000 15/32 .46875 11.90625 300 18.75 8.505 91.55 201.82 00000 7/16 .4375 11.1125 280 17.50 7.983 85.44 188.37 0000 13/32 .40625 10.31875 260 16.25 7.371 79.33 174.91 000 3/8 .375 9.525 240 15 6.804 73.24 161.46 00 11/32 .34375 8.73125 220 13.75 6.237 67.13 148.00 0 5/16 .3125 7.9375 200 12.50 5.67 61.03 134.55 1 9/32 .28125 7.14375 180 11.25 5.103 54.93 121.09 2 17/64 .265625 6.746875 170 10.625 4.819 51.88 114.37 3 1/4 .25 6.35 160 10 4.536 48.82 107.64 4 15/64 .234375 5.953125 150 9.375 4.252 45.77 100.91 5 7/32 .21875 5.55625 140 8.75 3.969 42.72 94.18 6 13/64 .203125 5.159375 130 8.125 3.685 39.67 87.45 7 3/16 .1875 4.7625 120 7.5 3.402 36.62 80.72 8 11/64 .171875 4.365625 110 6.875 3.118 33.57 74.00 9 5/32 .15625 3.96875 100 6.25 2.835 30.52 67.27 10 9/64 .140625 3.571875 90 5.625 2.552 27.46 60.55 11 1/8 .125 3.175 80 5 2.268 24.41 53.82 12 7/64 .109375 2.778125 70 4.375 1.984 21.36 47.09 13 3/32 .09375 2.38125 60 3.75 1.701 18.31 40.36 14 5/64 .078125 1.984375 50 3.125 1.417 15.26 33.64 15 9/128 .0703125 1.7859375 45 2.8125 1.276 13.73 30.27 16 1/16 .0625 1.5875 40 2.5 1.134 12.21 26.91 17 9/160 .05625 1.42875 36 2.25 1.021 10.99 24.22 18 1/20 .05 1.27 32 2 .9072 9.765 21.53 19 7/160 .04375 1.11125 28 1.75 .7938 8.544 18.84 20 3/80 .0375 .9525 24 1.50 .6804 7.324 16.15 21 11/320 .034375 .873125 22 1.375 .6237 6.713 14.80 22 1/32 .03125 .793750 20 1.25 .567 6.103 13.46 23 9/320 .028125 .714375 18 1.125 .5103 5.493 12.11 24 1/40 .025 .635 16 1 .4536 4.882 10.76 25 7/320 .021875 .555625 14 .875 .3969 4.272 9.42 26 3/160 .01875 .47625 12 .75 .3402 3.662 8.07 27 11/640 .0171875 .4365625 11 .6875 .3119 3.357 7.40 28 1/64 .015625 .396875 10 .625 .2835 3.052 6.73 29 9/640 .0140625 .3571875 9 .5625 .2551 2.746 6.05 30 1/80 .0125 .3175 8 .5 .2268 2.441 5.38 31 7/640 .0109375 .2778125 7 .4375 .1984 2.136 4.71 32 13/1280 .01015625 .25796875 6½ .40625 .1843 1.983 4.37 33 3/320 .009375 .238125 6 .375 .1701 1.831 4.04 34 11/1280 .00859375 .21828125 5½ .34375 .1559 1.678 3.70 35 5/640 .0078125 .1984375 5 .3125 .1417 1.526 3.36 36 9/1280 .00703125 .17859375 4½ .28125 .1276 1.373 3.03 37 17/2560 .006640625 .168671875 4¼ .265625 .1205 1.297 2.87 38 1/160 .00625 .15875 4 .25 .1134 1.221 2.69 The same and no other shall be used in determining duties and taxes levied by the United States of America on sheet and plate iron and steel. But this subchapter shall not be construed to increase duties upon any articles which may be imported.

(Mar. 3, 1893, ch. 221, § 1, 27 Stat. 746.)