ANSI B16.5 Class 400 Lap Joint Flanges
| NPS | Outside Diameter (O) (mm) | Thickness (T) (mm) | Bolt Circle (C) (mm) | Bolt Holes (in) | Number of Bolts |
|---|---|---|---|---|---|
| 1/2 | 95 | 14.2 | 66.5 | 5/8 | 4 |
| 3/4 | 117 | 15.7 | 82.6 | 3/4 | 4 |
| 1 | 124 | 17.5 | 88.9 | 3/4 | 4 |
| 1 1/4 | 133 | 20.6 | 98.6 | 3/4 | 4 |
| 1 1/2 | 155 | 22.4 | 114.3 | 7/8 | 4 |
| 2 | 165 | 25.4 | 127 | 3/4 | 8 |
| 2 1/2 | 190 | 28.4 | 149.4 | 7/8 | 8 |
| 3 | 210 | 31.8 | 168.1 | 7/8 | 8 |
| 3 1/2 | 229 | 35.1 | 184.2 | 1 | 8 |
| 4 | 254 | 35.1 | 200.2 | 1 | 8 |
| 5 | 279 | 38.1 | 235 | 1 | 8 |
| 6 | 318 | 41.1 | 269.7 | 1 | 12 |
| 8 | 381 | 47.8 | 330.2 | 1⅛ | 12 |
| 10 | 444 | 53.8 | 387.4 | 1¼ | 16 |
| 12 | 521 | 57.2 | 450.8 | 1⅜ | 16 |
| 14 | 584 | 60.5 | 514.4 | 1⅜ | 20 |
| 16 | 648 | 63.5 | 571.5 | 1½ | 20 |
| 18 | 711 | 66.5 | 628.6 | 1½ | 24 |
| 20 | 775 | 69.8 | 685.8 | 1⅝ | 24 |
| 22 | 838 | 73.2 | 743 | 1¾ | 24 |
| 24 | 914 | 76.2 | 812.8 | 1⅞ | 24 |