ANSI / ASME B16.5 Class 400 Weld Neck Flange Dimensions
| Nominal Pipe Size | Outside Diameter (O) | Thickness (T) | Raised Face Diameter (R) | Length Thru Hub (Y) | Hub Diameter (X) | Bore (B) | Approximate Weight (lbs) | Bolt Circle (C) | Number of Holes | Diameter of Holes |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2 | 3.75 | 0.56 | 1.38 | 2.06 | 1.50 | Specified by purchaser | 2 | 2.63 | 4 | 0.63 |
| 3/4 | 4.63 | 0.63 | 1.69 | 2.25 | 1.88 | Specified by purchaser | 4 | 3.25 | 4 | 0.75 |
| 1 | 4.88 | 0.69 | 2.00 | 2.44 | 2.13 | Specified by purchaser | 4 | 3.50 | 4 | 0.75 |
| 1 1/4 | 5.25 | 0.81 | 2.50 | 2.63 | 2.50 | Specified by purchaser | 6 | 3.88 | 4 | 0.75 |
| 1 1/2 | 6.13 | 0.88 | 2.88 | 2.75 | 2.75 | Specified by purchaser | 8 | 4.50 | 4 | 0.88 |
| 2 | 6.50 | 1.00 | 3.63 | 2.88 | 3.31 | Specified by purchaser | 12 | 5.00 | 8 | 0.75 |
| 2 1/2 | 7.50 | 1.13 | 4.13 | 3.13 | 3.94 | Specified by purchaser | 18 | 5.88 | 8 | 0.88 |
| 3 | 8.25 | 1.25 | 5.00 | 3.25 | 4.63 | Specified by purchaser | 23 | 6.63 | 8 | 0.88 |
| 3 1/2 | 9.00 | 1.38 | 5.50 | 3.38 | 5.25 | Specified by purchaser | 26 | 7.25 | 8 | 1.00 |
| 4 | 10.00 | 1.38 | 6.19 | 3.50 | 5.75 | Specified by purchaser | 35 | 7.88 | 8 | 1.00 |
| 5 | 11.00 | 1.50 | 7.31 | 4.00 | 7.00 | Specified by purchaser | 43 | 9.25 | 8 | 1.00 |
| 6 | 12.50 | 1.63 | 8.50 | 4.06 | 8.13 | Specified by purchaser | 57 | 10.63 | 12 | 1.00 |
| 8 | 15.00 | 1.88 | 10.63 | 4.63 | 10.25 | Specified by purchaser | 89 | 13.00 | 12 | 1.13 |
| 10 | 17.50 | 2.13 | 12.75 | 4.88 | 12.63 | Specified by purchaser | 125 | 15.25 | 16 | 1.25 |
| 12 | 20.50 | 2.25 | 15.00 | 5.38 | 14.75 | Specified by purchaser | 175 | 17.75 | 16 | 1.38 |
| 14 | 23.00 | 2.38 | 16.25 | 5.88 | 16.75 | Specified by purchaser | 230 | 20.25 | 20 | 1.38 |
| 16 | 25.50 | 2.50 | 18.50 | 6.00 | 19.00 | Specified by purchaser | 295 | 22.50 | 20 | 1.50 |
| 18 | 28.00 | 2.63 | 21.00 | 6.50 | 21.00 | Specified by purchaser | 350 | 24.75 | 24 | 1.50 |
| 20 | 30.50 | 2.75 | 23.00 | 6.63 | 23.13 | Specified by purchaser | 425 | 27.00 | 24 | 1.63 |
| 22 | 33.00 | 2.88 | 25.25 | 6.75 | 25.25 | Specified by purchaser | 505 | 29.25 | 24 | 1.75 |
| 24 | 36.00 | 3.00 | 27.25 | 6.88 | 27.63 | Specified by purchaser | 620 | 32.00 | 24 | 1.88 |
*Use 25.4 as a factor to convert into mm.