ANSI B16.5 Class 300 Lap Joint Flanges
| NPS (Nominal Pipe Size) | Outside Diameter (O) (mm) | Thickness (T) (mm) | Diameter of Bolt Circle (C) (mm) | Diameter of Bolt Holes (in) | Number of Bolts |
|---|---|---|---|---|---|
| 1/2 | 95 | 12.7 | 66.5 | 5/8 | 4 |
| 3/4 | 117 | 14.2 | 82.6 | 3/4 | 4 |
| 1 | 124 | 15.7 | 88.9 | 3/4 | 4 |
| 1 1/4 | 133 | 17.5 | 98.6 | 3/4 | 4 |
| 1 1/2 | 155 | 19 | 114.3 | 7/8 | 4 |
| 2 | 165 | 20.6 | 127 | 3/4 | 8 |
| 2 1/2 | 190 | 23.9 | 149.4 | 7/8 | 8 |
| 3 | 210 | 26.9 | 168.1 | 7/8 | 8 |
| 3 1/2 | 229 | 28.4 | 184.2 | 7/8 | 8 |
| 4 | 254 | 30.2 | 200.2 | 7/8 | 8 |
| 5 | 279 | 33.3 | 235 | 7/8 | 8 |
| 6 | 318 | 35.1 | 269.7 | 7/8 | 12 |
| 8 | 381 | 39.6 | 330.2 | 1 | 12 |
| 10 | 444 | 46 | 387.4 | 1⅛ | 16 |
| 12 | 521 | 49.3 | 450.8 | 1¼ | 16 |
| 14 | 584 | 52.3 | 514.4 | 1¼ | 20 |
| 16 | 648 | 55.6 | 571.5 | 1⅜ | 20 |
| 18 | 711 | 58.7 | 628.6 | 1⅜ | 24 |
| 20 | 775 | 62 | 685.8 | 1⅜ | 24 |
| 22 | 838 | 65 | 743 | 1⅝ | 24 |
| 24 | 914 | 68.3 | 812.8 | 1⅝ | 24 |