ANSI 250 or 300 Lb. Plate Flange Specifications
| Nominal Pipe Size | Pipe O.D. of Flange | Bore I.D. Diameter | Bolt Holes | Hole Diameter | Bolt Circle Diameter |
| 1/2 | 3 3/4 | .88 | 4 | 5/8 | 2 5/8 |
| 3/4 | 4 5/8 | 1.09 | 4 | 3/4 | 3 1/4 |
| 1 | 4 7/8 | 1.36 | 4 | 3/4 | 3 1/2 |
| 1 1/4 | 5 1/4 | 1.70 | 4 | 3/4 | 3 7/8 |
| 1 1/2 | 6 1/8 | 1.95 | 4 | 3/4 | 4 1/2 |
| 2 | 6 1/2 | 2.44 | 8 | 3/4 | 5 |
| 2 1/2 | 7 1/2 | 2.94 | 8 | 7/8 | 5 7/8 |
| 3 | 8 1/4 | 3.57 | 8 | 7/8 | 6 5/8 |
| 3 1/2 | 9 | 4.07 | 8 | 7/8 | 7 1/4 |
| 4 | 10 | 4.57 | 8 | 7/8 | 7 7/8 |
| 5 | 11 | 5.66 | 8 | 7/8 | 9 1/4 |
| 6 | 12 1/2 | 6.72 | 12 | 7/8 | 10 5/8 |
| 8 | 15 | 8.72 | 12 | 1 | 13 |
| 10 | 17 1/2 | 10.88 | 16 | 1 1/8 | 15 1/4 |
| 12 | 20 1/2 | 12.88 | 16 | 1 1/4 | 17 3/4 |
| 14 | 23 | 14.14 | 20 | 1 1/4 | 20 1/4 |
| 16 | 25 1/2 | 16.16 | 20 | 1 3/8 | 22 1/2 |
| 18 | 28 | 18.18 | 24 | 1 3/8 | 24 3/4 |
| 20 | 30 1/2 | 20.20 | 24 | 1 3/8 | 27 |
| 24 | 36 | 24.25 | 24 | 1 5/8 | 32 |