American wire gauge
American wire gauge ('AWG') is a way of specifying wire sizes, where each gauge represents a different wire diameter. It was originally applied to non-ferrous, conducting wire, but lately is commonly used to specify body piercing jewelry sizes in the US.
In common with many non-metric gauging systems, the measurement involved (wire diameter in this case) decreases with increasing gauge number.
Table of AWGs and approximate corresponding sizes
| AWG | Diameter mm | Diameter inches |
| 0000000 (6/0) | 14.732 | 0.5800 |
| 000000 (5/0) | 13.119 | 0.5165 |
| 00000 (4/0) | 11.684 | 0.4600 |
| 000 (3/0) | 10.404 | 0.4096 |
| 00 (2/0) | 9.266 | 0.3648 |
| 0 (1/0) | 8.252 | 0.3249 |