The gauge is used to specify the thickness of the sheet metal. The gauge is neither standard nor metric, and its value has nothing to do with those measuring systems.
The sheet metal thickness gauge for steel is based on a weight of 41.82 pounds per square foot per inch of thickness. This is called the steel plate manufacturer’s standard gauge.
Below is a chart of sheet metal gauge to mm/inch, including standard steel, aluminum, and galvanized steel.
| ALUMINUM | GAUGE | STEEL | GALVANIZED | |||
| mm | Inches | Inches | mm | Inches | mm | |
| 5.827 | 0.2294 | 3 | 0.2391 | 6.073 | ||
| 5.189 | 0.2043 | 4 | 0.2242 | 5.695 | ||
| 4.62 | 0.1819 | 5 | 0.2092 | 5.314 | ||
| 4.115 | 0.162 | 6 | 0.1793 | 4.935 | ||
| 3.665 | 0.1443 | 7 | 0.1793 | 4.554 | ||
| 3.264 | 0.1285 | 8 | 0.1644 | 4.176 | ||
| 2.906 | 0.1144 | 9 | 0.1495 | 3.797 | 0.1532 | 3.891 |
| 2.588 | 0.1019 | 10 | 0.1345 | 3.416 | 0.1382 | 3.51 |
| 2.304 | 0.0907 | 11 | 0.1196 | 3.03 | 0.1283 | 3.132 |
| 2.052 | 0.0808 | 12 | 0.1046 | 2.657 | 0.1084 | 2.753 |
| 1.829 | 0.072 | 13 | 0.0897 | 2.278 | 0.0934 | 2.372 |
| 1.628 | 0.0641 | 14 | 0.0747 | 1.897 | 0.0785 | 1.993 |
| 1.45 | 0.0571 | 15 | 0.0673 | 1.709 | 0.071 | 1.803 |
| 1.29 | 0.0508 | 16 | 0.0598 | 1.367 | 0.0635 | 1.161 |
| 1.151 | 0.0453 | 17 | 0.0538 | 1.367 | 0.0575 | 1.46 |
| 1.024 | 0.0403 | 18 | 0.0478 | 1.214 | 0.0516 | 1.31 |
| 0.912 | 0.0359 | 19 | 0.0418 | 1.062 | 0.0456 | 1.158 |
| 0.813 | 0.032 | 20 | 0.0359 | 0.912 | 0.0396 | 1.006 |
| 0.724 | 0.0258 | 21 | 0.0329 | 0.826 | 0.0366 | 0.093 |
| 0.643 | 0.0253 | 22 | 0.0299 | 0.759 | 0.0336 | 0.853 |
| 0.574 | 0.0226 | 23 | 0.0269 | 0.759 | 0.0306 | 0.777 |
| 0.511 | 0.0201 | 24 | 0.0239 | 0.607 | 0.0278 | 0.627 |
| 0.455 | 0.0179 | 25 | 0.0209 | 0.531 | 0.0247 | 0.627 |
| 0.404 | 0.0159 | 26 | 0.0179 | 0.455 | 0.0217 | 0.551 |
| 0.361 | 0.0142 | 27 | 0.0164 | 0.417 | 0.02 | 0.513 |
| 0.32 | 0.0126 | 28 | 0.0149 | 0.378 | 0.0187 | 0.475 |
| 0.287 | 0.0113 | 29 | 0.0135 | 0.343 | 0.0172 | 0.437 |
| 0.254 | 0.01 | 30 | 0.012 | 0.305 | 0.0157 | 0.399 |
| 0.226 | 0.0089 | 31 | 0.0105 | 0.267 | 0.0142 | 0.361 |
| 0.203 | 0.008 | 32 | 0.0097 | 0.246 | 0.0134 | 0.34 |
| 0.18 | 0.0071 | 33 | 0.009 | 0.246 | ||
| 0.16 | 0.0063 | 34 | 0.0082 | 0.208 | ||
| 0.142 | 0.0056 | 35 | 0.0075 | 0.191 | ||
| Gauge | Stainless Steel (mm) | Stainless Steel(Inch) |
|---|---|---|
| 4 | 5.954 | 0.2344 |
| 5 | 5.555 | 0.2187 |
| 6 | 5.159 | 0.2031 |
| 7 | 4.763 | 0.1875 |
| 8 | 4.191 | 0.165 |
| 9 | 3.967 | 0.1562 |
| 10 | 3.571 | 0.1406 |
| 11 | 3.175 | 0.125 |
| 12 | 2.779 | 0.1094 |
| 13 | 2.38 | 0.0937 |
| 14 | 1.984 | 0.0781 |
| 15 | 1.786 | 0.0703 |
| 16 | 1.588 | 0.0625 |
| 17 | 1.427 | 0.0562 |
| 18 | 1.27 | 0.05 |
| 19 | 1.11 | 0.0437 |
| 20 | 0.953 | 0.0375 |
| 21 | 0.874 | 0.0344 |
| 22 | 0.792 | 0.0312 |
| 23 | 0.714 | 0.0281 |
| 24 | 0.635 | 0.025 |
| 25 | 0.556 | 0.0219 |
| 26 | 0.475 | 0.0187 |
| 27 | 0.437 | 0.0172 |
| 28 | 0.396 | 0.0156 |
| 29 | 0.358 | 0.0141 |
| 30 | 0.318 | 0.0125 |
| 31 | 0.277 | 0.0109 |
| 32 | 0.259 | 0.0102 |
| 33 | 0.239 | 0.0094 |
| 34 | 0.218 | 0.0086 |
| 35 | 0.198 | 0.0078 |
| 36 | 0.178 | 0.007 |
| 37 | 0.168 | 0.0066 |
| 38 | 0.157 | 0.0062 |
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