Cast Iron Flanges - Stud Reference Chart
The number, diameter and length of studs for cast iron flanges class 125 and 250.
The studs sizes for cast iron flanges class 125 and 250 are indicated in the tables below. The sizes are for standard facing and standard pressure ratings flange to flange.
Cast Iron Flanges - Class 125
| NPS (in) | No. of Studs | Diameter of Stud (in) | Length of Stud (in) |
|---|---|---|---|
| 1/2 | 4 | 1/2 | 2-1/2 |
| 3/4 | 4 | 1/2 | 2-1/2 |
| 1 | 4 | 1/2 | 2-3/4 |
| 1-1/4 | 4 | 1/2 | 2-3/4 |
| 1-1/2 | 4 | 1/2 | 3 |
| 2 | 4 | 5/8 | 3-1/2 |
| 2-1/2 | 4 | 5/8 | 3-3/4 |
| 3 | 4 | 5/8 | 3-3/4 |
| 3-1/2 | 8 | 5/8 | 3-3/4 |
| 4 | 8 | 5/8 | 3-3/4 |
| 5 | 8 | 3/4 | 4 |
| 6 | 8 | 3/4 | 4-1/4 |
| 8 | 8 | 3/4 | 4-1/2 |
| 10 | 12 | 7/8 | 4-3/4 |
| 12 | 12 | 7/8 | 5 |
| 14 | 12 | 1 | 5-1/2 |
| 16 | 16 | 1 | 5-1/2 |
- 1 inch = 25.4 mm
Cast Iron Flanges - Class 250
| NPS (in) | No. of Studs | Diameter of Stud (in) | Length of Stud (in) |
|---|---|---|---|
| 1/2 | 4 | 1/2 | 2-3/4 |
| 3/4 | 4 | 5/8 | 3-1/4 |
| 1 | 4 | 5/8 | 3-1/4 |
| 1-1/4 | 4 | 5/8 | 3-1/2 |
| 1-1/2 | 4 | 5/8 | 3-3/4 |
| 2 | 8 | 5/8 | 3-3/4 |
| 2-1/2 | 8 | 5/8 | 4-1/4 |
| 3 | 8 | 5/8 | 4-1/2 |
| 3-1/2 | 8 | 5/8 | 4-1/2 |
| 4 | 8 | 5/8 | 4-3/4 |
| 5 | 8 | 5/8 | 5 |
| 6 | 12 | 5/8 | 5 |
| 8 | 12 | 7/8 | 5-3/4 |
| 10 | 16 | 1 | 6-1/2 |
| 12 | 16 | 1-1/8 | 7 |
| 14 | 20 | 1-1/8 | 7-1/4 |
| 16 | 20 | 1-1/4 | 7-3/4 |
| 18 | 24 | 1-1/4 | 8 |
