Stud Bolt dimensions for ASME flanges.

| Nom Pipe Size (inches) |
Nom Pipe Size (mm) |
Number of bolts |
Dia (inch) x Length (mm) |
Ring Number |
|---|---|---|---|---|
| 1/2 | 15 | 4 | 3/4 x 120 | R13 |
| 3/4 | 20 | 4 | 3/4 x 125 | R16 |
| 1 | 25 | 4 | 7/8 x 140 | R18 |
| 1 1/2 | 40 | 4 | 1 1/8 x 170 | R23 |
| 2 | 50 | 8 | 1 x 180 | R26 |
| 2 1/2 | 65 | 8 | 1 1/8 x 205 | R28 |
| 3 | 80 | 8 | 1 1/4 x 230 | R32 |
| 4 | 100 | 8 | 1 1/2 x 260 | R38 |
| 6 | 150 | 8 | 2 x 355 | R47 |
| 8 | 200 | 12 | 2 x 395 | R51 |
| 10 | 250 | 12 | 2 1/2 x 510 | R55 |
| 12 | 300 | 12 | 2 3/4 x 560 | R60 |