Check out this handy reference chart to convert gauge sizes to MM or Inches. An important note on gauge sizes for silver and gold is that as the gauge size increases, the mm size decreases. When rolling ingots in your rolling mill from silver, it is as simple as using a pair of digital calipers to measure the beginning size and ending size.
A downloaded version of this PDF can be found by clicking here
| B&S Gauge | Millimeters | Inches |
|---|---|---|
| 1 | 7.348 mm | .289" |
| 2 | 6.543 mm | .258" |
| 3 | 5.827 mm | .229" |
| 4 | 5.189 mm | .204" |
| 5 | 4.620 mm | .182" |
| 6 | 4.115 mm | .162" |
| 7 | 3.663 mm | .144" |
| 8 | 3.261 mm | .129" |
| 9 | 2.906 mm | .114" |
| 10 | 2.586 mm | .102" |
| 11 | 2.304 mm | .090" |
| 12 | 2.052 mm | .080" |
| 13 | 1.826 mm | .072" |
| 14 | 1.626 mm | .064" |
| 15 | 1.448 mm | .057" |
| 16 | 1.290 mm | .050" |
| 17 | 1.148 mm | .045" |
| 18 | 1.024 mm | .040" |
| 19 | 0.912 mm | .036" |
| 20 | 0.813 mm | .032" |
| 21 | 0.724 mm | .029" |
| 22 | 0.643 mm | .025" |
| 23 | 0.574 mm | .023" |
| 24 | 0.511 mm | .020" |
| 25 | 0.455 mm | .018" |
| 26 | 0.404 mm | .016" |
| 27 | 0.361 mm | .014" |
| 28 | 0.330 mm | .013" |
| 29 | 0.279 mm | .011" |
| 30 | 0.254 mm | .010" |
