01
Weld Neck Flange
ANSI B16.5 Class 2500 Forged Flanges
02
Threaded Flange
03
Lap Joint Flange
04
Blind Flange
| Nom. Pipe Size | O | T | R | X | #/Dia of Holesa | Bolt Circle Dia | B2b | B3 | H | L | L2 | L3 | r | C | Thr |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ½ | 5.25 | 1.19 | 1.38 | 1.69 | 4-0.88 | 3.5 |  |
0.9 | 0.84 | 1.56 | 2.88 | 1.56 | 0.12 | 0.93 | 1.12 |
| ¾ | 5.5 | 1.25 | 1.69 | 2 | 4-0.88 | 3.75 | 1.11 | 1.05 | 1.69 | 3.12 | 1.69 | 0.12 | 1.14 | 1.25 | |
| 1 | 6.25 | 1.38 | 2 | 2.25 | 4-1.00 | 4.25 | 1.38 | 1.32 | 1.88 | 3.5 | 1.88 | 0.12 | 1.41 | 1.38 | |
| 1¼ | 7.25 | 1.5 | 2.5 | 2.88 | 4-1.12 | 5.13 | 1.72 | 1.66 | 2.06 | 3.75 | 2.06 | 0.19 | 1.75 | 1.5 | |
| 1½ | 8 | 1.75 | 2.88 | 3.12 | 4-1.25 | 5.75 | 1.97 | 1.9 | 2.38 | 4.38 | 2.38 | 0.25 | 1.99 | 1.75 | |
| 2 | 9.25 | 2 | 3.63 | 3.75 | 8-1.12 | 6.75 | 2.46 | 2.38 | 2.75 | 5 | 2.75 | 0.31 | 2.5 | 2 | |
| 2½ | 10.5 | 2.25 | 4.13 | 4.5 | 8-1.25 | 7.75 | 2.97 | 2.88 | 3.12 | 5.62 | 3.12 | 0.31 | 3 | 2.25 | |
| 3 | 12 | 2.62 | 5 | 5.25 | 8-1.38 | 9 | 3.6 | 3.5 | …. | 6.62 | 3.62 | 0.38 | …. | …. | |
| 4 | 14 | 3 | 6.19 | 6.5 | 8-1.63 | 10.75 | 4.6 | 4.5 | …. | 7.5 | 4.25 | 0.44 | …. | …. | |
| 5 | 16.5 | 3.62 | 7.31 | 8 | 8-1.88 | 12.75 | 5.69 | 5.56 | …. | 9 | 5.12 | 0.44 | …. | …. | |
| 6 | 19 | 4.25 | 8.5 | 9.25 | 8-2.12 | 14.5 | 6.75 | 6.63 | …. | 10.75 | 6 | 0.5 | …. | …. | |
| 8 | 21.75 | 5 | 10.63 | 12 | 12-2.12 | 17.25 | 8.75 | 8.63 | …. | 12.5 | 7 | 0.5 | …. | …. | |
| 10 | 26.5 | 6.5 | 12.75 | 14.75 | 12-2.63 | 21.25 | 10.92 | 10.75 | …. | 16.5 | 9 | 0.5 | …. | …. | |
| 12 | 30 | 7.25 | 15 | 17.38 | 12-2.88 | 24.38 | 12.92 | 12.75 | …. | 18.25 | 10 | 0.5 | …. | …. |
Dimensions are in inches.
(a)- Bolt hole diameter 1/8 in. larger than bolt diameter. (b)- Standard bore dimensions provided. See bore chart for other wall thicknesses. (c)- This dimension is commonly associated with “true” lap joints. Industry standard is to make to the slip on length through the hub.
