A sheet metal gauge (sometimes spelt “gauge”) specifies the typical thickness of sheet metal for a particular material. Lower gauge numbers mean thicker metal sheets, whereas higher gauge numbers indicate thinner metal sheets. The numbers are irrelevant to standard measures such as inches or millimetres since they are independent of existing systems.
The normal sheet metal gauge range starts at 30 on the thin end and descends to 7 on the thick end. However, the exact thickness and gauge will vary based on the type of metal. Many metals may be manufactured in gauges as high as 36 or as low as 3, well above the typical range.
Steel sheet metal thickness gauges are based on a weight of 41.82 pounds per square foot per inch of thickness. This is known as the Manufacturers’ Standard Gage for Sheet Steel. The thicknesses of other materials, such as aluminium and brass, will vary. Thus, a 10 gauge steel sheet with a thickness of 0.1345 inches will weigh 41.82*0.1345 = 5.625 pounds per square foot.
For example, 16 ga CRS weighs 2.5 pounds per square foot. The weight of 18 ga CRS is 2.0 pounds per square foot, whereas 20 ga CRS is 1.5 pounds per square foot.
Standard sheet metal gauges
| Gauge | Steel | Carbon Steel eh | Galvanized Steel | Stainless Steel | Aluminum | Steel (mm) |
|---|---|---|---|---|---|---|
| 07 | 0.179 | – | – | – | – | 4.547 |
| 08 | 0.165 | 0.1644 | 0.1681 | 0.1719 | 0.1285 | 4.191 |
| 09 | 0.150 | 0.1495 | 0.1532 | 0.1563 | 0.1144 | 3.810 |
| 10 | 0.135 | 0.1345 | 0.1382 | 0.1406 | 0.1019 | 3.429 |
| 11 | 0.120 | 0.1196 | 0.1233 | 0.1250 | 0.0907 | 3.048 |
| 12 | 0.105 | 0.1046 | 0.1084 | 0.1094 | 0.0808 | 2.677 |
| 13 | 0.09 | – | – | 0.094 | 0.072 | 2.286 |
| 14 | 0.075 | 0.0747 | 0.0785 | 0.0781 | 0.0641 | 1.905 |
| 15 | 0.067 | – | – | 0.07 | 0.057 | 1.702 |
| 16 | 0.060 | 0.0598 | 0.0635 | 0.0625 | 0.0508 | 1.524 |
| 17 | 0.054 | – | – | 0.056 | 0.045 | 1.372 |
| 18 | 0.047 | 0.0478 | 0.0516 | 0.0500 | 0.0403 | 1.1938 |
| 19 | 0.042 | – | – | 0.044 | 0.036 | 1.067 |
| 20 | 0.036 | 0.0359 | 0.0396 | 0.0375 | 0.0320 | 0.9144 |
| 21 | 0.033 | – | – | 0.034 | 0.028 | 0.838 |
| 22 | 0.03 | – | – | 0.031 | 0.025 | 0.762 |
| 23 | 0.027 | – | – | 0.028 | 0.023 | 0.686 |
| 24 | 0.024 | – | – | 0.025 | 0.02 | 0.61 |
| 25 | 0.021 | – | – | 0.022 | 0.018 | 0.533 |
| 26 | 0.018 | – | – | 0.019 | 0.017 | 0.457 |
| 27 | 0.016 | – | – | 0.017 | 0.014 | 0.406 |
| 28 | 0.015 | – | – | 0.016 | – | 0.381 |
| 29 | 0.014 | – | – | 0.014 | – | 0.356 |
| 30 | 0.012 | – | – | 0.013 | – | 0.305 |
| 31 | – | – | – | 0.011 | – | – |
Thickness is expressed in inches except for the mm column (1in = 25.4mm).
This chart is provided for reference purposes only; it is strongly advised that you consult with a local supplier to see what exact thickness values are used in your area.
