Answer
Dec 18, 2025 - 09:10 AM
Per the manufacturer - the Class 150# Bronze NPT Threaded Floor Flanges (4 Bolt Holes) - have the following bolt hole sizes for each size listed below:
| NPS Size (in.) | Bolt Hole Size (inches) |
| 1/4 in. | 0.28 |
| 3/8 in. | 0.28 |
| 1/2 in. | 0.25 |
| 3/4 in. | 0.25 |
| 1 in. | 0.25 |
| 1-1/4 in. | 0.25 |
| 1-1/2 in. | 0.31 |
| 2 in. | 0.31 |
