| For a given | protractor angle ring inside diameter ring width engraving tool shank diameter | θ D w d | } | degrees inches or millimeters |
this calculator will determine the fourth value if you enter any three.
| θ = sin-1 | d | + tan-1 | w |
| √4D2w2 | D |
| w = | 2·D·sinθ - d |
| 2·cosθ |
| d = 2·D·sinθ - 2·w·cosθ |
| D = | w | + | d |
| tanθ | 2·sinθ |