ANSI B16.5 Class 2500 Lap Joint Flanges
| NPS | Outside Diameter (O) (mm) | Thickness (T) (mm) | Bolt Circle (C) (mm) | Bolt Holes (in) | Number of Bolts |
|---|---|---|---|---|---|
| 1/2 | 133 | 30.2 | 88.9 | 7/8 | 4 |
| 3/4 | 140 | 31.8 | 95.2 | 7/8 | 4 |
| 1 | 159 | 35.1 | 108 | 1 | 4 |
| 1 1/4 | 184 | 38.1 | 130 | 1⅛ | 4 |
| 1 1/2 | 203 | 44.4 | 146 | 1¼ | 4 |
| 2 | 235 | 50.8 | 171.4 | 1⅛ | 8 |
| 2 1/2 | 267 | 57.2 | 196.8 | 1¼ | 8 |
| 3 | 305 | 66.5 | 228.6 | 1⅜ | 8 |
| 4 | 356 | 76.2 | 273 | 1⅝ | 8 |
| 5 | 419 | 91.9 | 323.8 | 1⅞ | 8 |
| 6 | 483 | 108 | 368.3 | 2-1/8″ | 8 |
| 8 | 552 | 127 | 438.2 | 2-1/4″ | 12 |
| 10 | 673 | 165.1 | 539.8 | 2-5/8″ | 12 |
| 12 | 762 | 184.2 | 619.3 | 2-7/8″ | 12 |