This table displays Flange Dimensional Tolerances by inside, outside, and contact diameter, thickness, and drilling tolerances for bolt holes diameter and spacing. These standard flange dimensional tolerances are ideal when other specifications aren’t used.
| OUTSIDE DIAMETER | When O.D. is 24″ or less | +0.125″ , -0.0625″ |
| When O.D. over is 24″ | +0.125″ , -0.125″ | |
| INSIDE DIAMETER | When I.D. is 10″ or less | +0.03125″ , -0″ |
| When I.D. over is 10″ | +0.0625″ , -0″ | |
| CONTACT FACE DIAMETER | Raised Face | +0.0156″ , -0.0156″ |
| DRILLING | Bolt Hole Diameter | +0.03125″ , -0.03125″ |
| Bolt Circle Diameter | +0.0625″ , -0.0625″ | |
| Bolt Hole Spacing | +0.03125″ , -0.03125″ | |
| THICKNESS | When nominal size is 18″ or less | +0.125″ , -0 |
| When nominal size is over 18″ | +0.1875″ , -0 |
