US ring sizes

US sizes 4-12, according to a [size guide from wikipedia](https://en.wikipedia.org/wiki/Ring_size).

inner diameter = 0.8128 * S + 11.63, where S is the US size

recommend printing with 0.1 mm layer height for better dimensional accuracy and slightly crisper text. each size was modeled at 0.1 mm bigger than the standard to allow for typical filament smoosh, and the final product on my bambu labs printer turned out about perfect.

real-world sizes vary from seller to seller tho so be aware this isn't a definitive guide but pretty ok for something you can print.

| size (US) | inner diameter (mm) |
| --- | --- |
| 4 | 14.9 |
| 4.5 | 15.3 |
| 5 | 15.7 |
| 5.5 | 16.1 |
| 6 | 16.5 |
| 6.5 | 16.9 |
| 7 | 17.3 |
| 7.5 | 17.7 |
| 8 | 18.1 |
| 8.5 | 18.5 |
| 9 | 19.0 |
| 9.5 | 19.4 |
| 10 | 19.8 |
| 10.5 | 20.2 |
| 11 | 20.6 |
| 11.5 | 21.0 |
| 12 | 21.4 |
| 12.5 | 21.8 |

i used onshape to model this, [file available here](https://cad.onshape.com/documents/383d987