Here\’s the table below for ASME B16.5 Class 150 Flanges
| NPS | DIA bolts (in) |
Length RF |
Length RTJ |
Number of bolts |
| 1/2 | 1/2 | 55 | 4 | |
| 3/4 | 1/2 | 65 | 4 | |
| 1 | 1/2 | 65 | 75 | 4 |
| 1¼ | 1/2 | 70 | 85 | 4 |
| 1½ | 1/2 | 70 | 85 | 4 |
| 2 | 5/8 | 85 | 95 | 4 |
| 2½ | 5/8 | 90 | 100 | 4 |
| 3 | 5/8 | 90 | 100 | 4 |
| 3½ | 5/8 | 90 | 100 | 8 |
| 4 | 5/8 | 90 | 100 | 8 |
| 5 | 3/4 | 95 | 110 | 8 |
| 6 | 3/4 | 100 | 115 | 8 |
| 8 | 3/4 | 110 | 120 | 8 |
| 10 | 7/8 | 115 | 125 | 12 |
| 12 | 7/8 | 120 | 135 | 12 |
| 14 | 1 | 135 | 145 | 12 |
| 16 | 1 | 135 | 145 | 16 |
| 18 | 1.1/8 | 145 | 160 | 16 |
| 20 | 1.1/8 | 160 | 170 | 20 |
| 24 | 1¼ | 170 | 185 | 20 |
General notes:
- Dimensions are in millimeters unless otherwise indicated.
- Length dimensional tolerances for all Stud Bolts:
length to 12 inch tolerance = ± 1.6 mm
length over 12 inch to 18 inch tolerance = ± 3.2 mm
length over 18 inch tolerance = ± 6.4 mm - The length of the Stud Bolt does not include the height of the chamfers (points).
