Converting Sheet Metal Gauge To Thickness In Inches

Working with sheet metal, as shown in Figure 1, gauge sizes can be confusing at the best of times. Sheet metal gauges work opposite to what one might consider the norm. The smaller the number, the thicker the material. Hence, 4 gauge material is thicker than 6 gauge material.

Figure 1 - Sheet metal

To make things more complex, the conversion from gauge thickness is different depending on the type of metal being used.

Table 1 provides a set of conversion tables for the most common sheet metals:

• Steel
• Galvanized Steel
• Aluminum
• Stainless Steel (Series 300)
• Copper (Alloy 110)
 Table 1 - Sheet Metal Gauge To Thickness In Inches Gauge Steel In Inches Galvanized Steel In Inches Aluminum In Inches Stainless Steel, Series 300, In Inches Copper, Alloy 110, In Inches 3 0.2391 0.2294 4 0.2242 0.2043 5 0.2092 0.1819 6 0.1943 0.1620 7 0.1793 0.1443 8 0.1644 0.1285 9 0.1495 0.1532 0.1144 10 0.1345 0.1382 0.1019 0.134 11 0.1196 0.1233 0.0907 0.119 12 0.1046 0.1084 0.0808 0.103 13 0.0897 0.0934 0.0720 14 0.0747 0.0785 0.0641 0.074 15 0.0673 0.0710 0.0571 16 0.0598 0.0635 0.0508 0.059 17 0.0538 0.0575 0.0453 18 0.0478 0.0516 0.0403 0.047 0.040 19 0.0418 0.0456 0.0359 20 0.0359 0.0396 0.0320 0.035 0.032 21 0.0329 0.0366 0.0285 22 0.0299 0.0336 0.0253 0.030 0.025 23 0.0269 0.0306 0.0226 24 0.0239 0.0276 0.0201 0.024 0.020 25 0.0209 0.0247 0.0179 26 0.0179 0.0217 0.0159 0.019 0.0159 27 0.0164 0.0202 0.0142 0.0135 28 0.0149 0.0187 0.0126 0.0126 29 0.0135 0.0172 0.0113 30 0.0120 0.0157 0.0100 0.010 31 0.0105 0.0142 0.0089 32 0.0097 0.0134 0.0080 33 0.0090 0.0071 34 0.0082 0.0063 35 0.0075 0.0056 36 0.0067 0.005 37 0.0064 38 0.0060