Weld Neck Flanges
Like lap joint flanges, weld neck flanges require butt welding for installation. However, their integrity, performance in systems with multiple repeat bends, and the ability to use them in high-pressure and high-temperature systems make them a leading choice for process piping.
- Size Range | 1/2″ – 36″ NPS (Larger sizes available upon request)
- Classes | ASME/ANSI 150, 300, 600, 900, 1500, 2500
- Stainless Steel Grades | 304, 304L, 316, 316L, 316L, 317L, 321 , 347 *
- Special Alloys | 2205, 254SMo, Monel, Inconel *
- Chrome Moly | P5, P9, P11, P22, P91 *
- Standards | ASTM / ASME / ANSI
WELDING NECK FLANGE DIMENSIONS IN INCHES

WN CLASS 150 (IN INCH)
Weld neck flange dimensions class 150 (ASME B16.5) in inches
| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 0.62″ | 3.50″ | 2.38″ | 1.38″ | .063″ | 1.19″ | 0.84″ | 1.88″ | .38″ | 1.82″ | .62″ | 4 |
| 3/4″ | 0.82″ | 3.88″ | 2.75″ | 1.69″ | .063″ | 1.50″ | 1.05″ | 2.06″ | .44″ | 2.00″ | .62″ | 4 |
| 1″ | 1.05″ | 4.25″ | 3.12″ | 2.00″ | .063″ | 1.94″ | 1.32″ | 2.19″ | .50″ | 2.13″ | .62″ | 4 |
| 1-1/4″ | 1.38″ | 4.62″ | 3.50″ | 2.50″ | .063″ | 2.31″ | 1.66″ | 2.25″ | .56″ | 2.19″ | .62″ | 4 |
| 1-1/2″ | 1.61″ | 5.00″ | 3.88″ | 2.88″ | .063″ | 2.56″ | 1.90″ | 2.44″ | .62″ | 2.38″ | .62″ | 4 |
| 2″ | 2.07″ | 6.00″ | 4.75″ | 3.62″ | .063″ | 3.06″ | 2.38″ | 2.50″ | .69″ | 2.44″ | .75″ | 4 |
| 2-1/2″ | 2.47″ | 7.00″ | 5.50″ | 4.12″ | .063″ | 3.56″ | 2.88″ | 2.75″ | .82″ | 2.69″ | .75″ | 4 |
| 3″ | 3.07″ | 7.50″ | 6.00″ | 5.00″ | .063″ | 4.25″ | 3.50″ | 2.75″ | .88″ | 2.69″ | .75″ | 4 |
| 3-1/2″ | 3.55″ | 8.50″ | 7.00″ | 5.50″ | .063″ | 4.81″ | 4.00″ | 2.81″ | .88″ | 2.75″ | .75″ | 8 |
| 4″ | 4.03″ | 9.00″ | 7.50″ | 6.19″ | .063″ | 5.31″ | 4.50″ | 3.00″ | .88″ | 2.94″ | .75″ | 8 |
| 5″ | 5.05″ | 10.00″ | 8.50″ | 7.31″ | .063″ | 6.44″ | 5.56″ | 3.50″ | .88″ | 3.44″ | .88″ | 8 |
| 6″ | 6.07″ | 11.00″ | 9.50″ | 8.50″ | .063″ | 7.56″ | 6.63″ | 3.50″ | .94″ | 3.44″ | .88″ | 8 |
| 8″ | 7.98″ | 13.50″ | 11.75″ | 10.62″ | .063″ | 9.69″ | 8.63″ | 4.00″ | 1.06″ | 3.94″ | .88″ | 8 |
| 10″ | 10.02″ | 16.00″ | 14.25″ | 12.75″ | .063″ | 12.00″ | 10.75″ | 4.00″ | 1.13″ | 3.94″ | 1.00″ | 12 |
| 12″ | 12.00″ | 19.00″ | 17.00″ | 15.00″ | .063″ | 14.38″ | 12.75″ | 4.50″ | 1.19″ | 4.44″ | 1.00″ | 12 |
| 14″ | 13.25″ | 21.00″ | 18.75″ | 16.25″ | .063″ | 15.75″ | 14.00″ | 5.00″ | 1.32″ | 4.94″ | 1.12″ | 12 |
| 16″ | 15.25″ | 23.50″ | 21.25″ | 18.50″ | .063″ | 18.00″ | 16.00″ | 5.00″ | 1.38″ | 4.94″ | 1.12″ | 16 |
| 18″ | 17.25″ | 25.00″ | 22.75″ | 21.00″ | .063″ | 19.88″ | 18.00″ | 5.50″ | 1.50″ | 5.44″ | 1.25″ | 16 |
| 20″ | 19.25″ | 27.50″ | 25.00″ | 23.00″ | .063″ | 22.00″ | 20.00″ | 5.69″ | 1.63″ | 5.63″ | 1.25″ | 20 |
| 22″ | 21.25″ | 29.50″ | 27.25″ | 25.25″ | .063″ | 24.25″ | 22.00″ | 5.88″ | 1.75″ | 5.82″ | 1.38″ | 20 |
| 24″ | 23.25″ | 32.00″ | 29.50″ | 27.25″ | .063″ | 26.12″ | 24.00″ | 6.00″ | 1.82″ | 5.94″ | 1.38″ | 20 |
WN CLASS 300 (IN INCH)
Weld neck flange dimensions class 300 (ASME B16.5) in inches

| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 0.62″ | 3.75″ | 2.62″ | 1.38″ | .063″ | 1.50″ | 0.84″ | 2.06″ | .50″ | 2.00″ | 0.62″ | 4 |
| 3/4″ | 0.82″ | 4.62″ | 3.25″ | 1.69″ | .063″ | 1.88″ | 1.05″ | 2.25″ | .56″ | 2.19″ | 0.75″ | 4 |
| 1″ | 1.05″ | 4.88″ | 3.50″ | 2.00″ | .063″ | 2.12″ | 1.32″ | 2.44″ | .63″ | 2.38″ | 0.75″ | 4 |
| 1-1/4″ | 1.38″ | 5.25″ | 3.88″ | 2.50″ | .063″ | 2.50″ | 1.66″ | 2.56″ | .69″ | 2.50″ | 0.75″ | 4 |
| 1-1/2″ | 1.61″ | 6.12″ | 4.50″ | 2.88″ | .063″ | 2.75″ | 1.90″ | 2.69″ | .75″ | 2.63″ | 0.88″ | 4 |
| 2″ | 2.07″ | 6.50″ | 5.00″ | 3.62″ | .063″ | 3.31″ | 2.38″ | 2.75″ | .82″ | 2.69″ | 0.75″ | 8 |
| 2-1/2″ | 2.47″ | 7.50″ | 5.88″ | 4.12″ | .063″ | 3.94″ | 2.88″ | 3.00″ | .94″ | 2.94″ | 0.88″ | 8 |
| 3″ | 3.07″ | 8.25″ | 6.62″ | 5.00″ | .063″ | 4.62″ | 3.50″ | 3.12″ | 1.06″ | 3.06″ | 0.88″ | 8 |
| 3-1/2″ | 3.55″ | 9.00″ | 7.25″ | 5.50″ | .063″ | 5.25″ | 4.00″ | 3.19″ | 1.13″ | 3.13″ | 0.88″ | 8 |
| 4″ | 4.03″ | 10.00″ | 7.88″ | 6.19″ | .063″ | 5.75″ | 4.50″ | 3.38″ | 1.19″ | 3.32″ | 0.88″ | 8 |
| 5″ | 5.05″ | 11.00″ | 9.25″ | 7.31″ | .063″ | 7.00″ | 5.56″ | 3.88″ | 1.32″ | 3.82″ | 0.88″ | 8 |
| 6″ | 6.07″ | 12.50″ | 10.62″ | 8.50″ | .063″ | 8.12″ | 6.63″ | 3.88″ | 1.38″ | 3.82″ | 0.88″ | 12 |
| 8″ | 7.98″ | 15.00″ | 13.00″ | 10.62″ | .063″ | 10.25″ | 8.63″ | 4.38″ | 1.56″ | 4.32″ | 1.00″ | 12 |
| 10″ | 10.02″ | 17.50″ | 15.25″ | 12.75″ | .063″ | 12.62″ | 10.75″ | 4.62″ | 1.82″ | 4.56″ | 1.12″ | 16 |
| 12″ | 12.00″ | 20.50″ | 17.75″ | 15.00″ | .063″ | 14.75″ | 12.75″ | 5.12″ | 1.94″ | 5.06″ | 1.25″ | 16 |
| 14″ | 13.25″ | 23.00″ | 20.25″ | 16.25″ | .063″ | 16.75″ | 14.00″ | 5.62″ | 2.06″ | 5.56″ | 1.25″ | 20 |
| 16″ | 15.25″ | 25.50″ | 22.50″ | 18.50″ | .063″ | 19.00″ | 16.00″ | 5.75″ | 2.19″ | 5.69″ | 1.38″ | 20 |
| 18″ | 17.25″ | 28.00″ | 24.75″ | 21.00″ | .063″ | 21.00″ | 18.00″ | 6.25″ | 2.32″ | 6.19″ | 1.38″ | 24 |
| 20″ | 19.25″ | 30.50″ | 27.00″ | 23.00″ | .063″ | 23.12″ | 20.00″ | 6.38″ | 2.44″ | 6.32″ | 1.38″ | 24 |
| 22″ | 21.25″ | 33.00″ | 29.25″ | 25.25″ | .063″ | 25.25″ | 22.00″ | 6.50″ | 2.57″ | 6.44″ | 1.62″ | 24 |
| 24″ | 23.25″ | 36.00″ | 32.0″ | 27.25″ | .063″ | 27.62″ | 24.00″ | 6.62″ | 2.69″ | 6.56″ | 1.62″ | 24 |
WN CLASS 400 (IN INCH)
Weld neck flange dimensions class 400 (ASME B16.5) in inches

| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | .55″ | 3.75″ | 2.62″ | 1.38″ | .250″ | 1.50″ | 0.84″ | 2.31″ | 0.56″ | 2.06″ | 0.62″ | 4 |
| 3/4″ | .74″ | 4.62″ | 3.25″ | 1.69″ | .250″ | 1.88″ | 1.05″ | 2.50″ | 0.62″ | 2.25″ | 0.75″ | 4 |
| 1″ | .96″ | 4.88″ | 3.50″ | 2.00″ | .250″ | 2.12″ | 1.32″ | 2.69″ | 0.69″ | 2.44″ | 0.75″ | 4 |
| 1-1/4″ | 1.28″ | 5.25″ | 3.88″ | 2.50″ | .250″ | 2.50″ | 1.66″ | 2.87″ | 0.81″ | 2.62″ | 0.75″ | 4 |
| 1-1/2″ | 1.50″ | 6.12″ | 4.50″ | 2.88″ | .250″ | 2.75″ | 1.90″ | 3.00″ | 0.88″ | 2.75″ | 0.88″ | 4 |
| 2″ | 1.94″ | 6.50″ | 5.00″ | 3.62″ | .250″ | 3.31″ | 2.38″ | 3.13″ | 1.00″ | 2.88″ | 0.75″ | 8 |
| 2-1/2″ | 2.32″ | 7.50″ | 5.88″ | 4.12″ | .250″ | 3.94″ | 2.88″ | 3.37″ | 1.12″ | 3.12″ | 0.88″ | 8 |
| 3″ | 2.90″ | 8.25″ | 6.62″ | 5.00″ | .250″ | 4.62″ | 3.50″ | 3.50″ | 1.25″ | 3.25″ | 0.88″ | 8 |
| 3-1/2″ | 3.36″ | 9.00″ | 7.25″ | 5.50″ | .250″ | 5.25″ | 4.00″ | 3.63″ | 1.38″ | 3.38″ | 1.00″ | 8 |
| 4″ | 3.83″ | 10.00″ | 7.88″ | 6.19″ | .250″ | 5.75″ | 4.50″ | 3.75″ | 1.38″ | 3.50″ | 1.00″ | 8 |
| 5″ | 4.81″ | 11.00″ | 9.25″ | 7.31″ | .250″ | 7.00″ | 5.56″ | 4.25″ | 1.50″ | 4.00″ | 1.00″ | 8 |
| 6″ | 5.76″ | 12.50″ | 10.62″ | 8.50″ | .250″ | 8.12″ | 6.63″ | 4.31″ | 1.62″ | 4.06″ | 1.00″ | 12 |
| 8″ | 7.63″ | 15.00″ | 13.00″ | 10.62″ | .250″ | 10.25″ | 8.63″ | 4.87″ | 1.88″ | 4.62″ | 1.12″ | 12 |
| 10″ | 9.75″ | 17.50″ | 15.25″ | 12.75″ | .250″ | 12.62″ | 10.75″ | 5.13″ | 2.12″ | 4.88″ | 1.25″ | 16 |
| 12″ | 11.75″ | 20.50″ | 17.75″ | 15.00″ | .250″ | 14.75″ | 12.75″ | 5.63″ | 2.25″ | 5.38″ | 1.38″ | 16 |
| 14″ | 13.00″ | 23.00″ | 20.25″ | 16.25″ | .250″ | 16.75″ | 14.00″ | 6.13″ | 2.38″ | 5.88″ | 1.38″ | 20 |
| 16″ | 15.00″ | 25.50″ | 22.50″ | 18.50″ | .250″ | 19.00″ | 16.00″ | 6.25″ | 2.50″ | 6.00″ | 1.50″ | 20 |
| 18″ | 17.00″ | 28.00″ | 24.75″ | 21.00″ | .250″ | 21.00″ | 18.00″ | 6.75″ | 2.62″ | 6.50″ | 1.50″ | 24 |
| 20″ | 19.00″ | 30.50″ | 27.00″ | 23.00″ | .250″ | 23.12″ | 20.00″ | 6.87″ | 2.75″ | 6.62″ | 1.62″ | 24 |
| 22″ | 21.00″ | 33.00″ | 29.25″ | 25.25″ | .250″ | 25.25″ | 22.00″ | 7.00″ | 2.88″ | 6.75″ | 1.75″ | 24 |
| 24″ | 23.00″ | 36.00″ | 32.00″ | 27.25″ | .250″ | 27.62″ | 24.00″ | 7.13″ | 3.00″ | 6.88″ | 1.88″ | 24 |
WN CLASS 600 (IN INCH)
Weld neck flange dimensions class 600 (ASME B16.5) in inches

| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 0.55″ | 3.75″ | 2.62″ | 1.38″ | .250″ | 1.50″ | 0.84″ | 2.31″ | 0.56″ | 2.06″ | 0.62″ | 4 |
| 3/4″ | 0.74″ | 4.62″ | 3.25″ | 1.69″ | .250″ | 1.88″ | 1.05″ | 2.50″ | 0.62″ | 2.25″ | 0.75″ | 4 |
| 1″ | 0.96″ | 4.88″ | 3.50″ | 2.00″ | .250″ | 2.12″ | 1.32″ | 2.69″ | 0.69″ | 2.44″ | 0.75″ | 4 |
| 1-1/4″ | 1.28″ | 5.25″ | 3.88″ | 2.50″ | .250″ | 2.50″ | 1.66″ | 2.87″ | 0.81″ | 2.62″ | 0.75″ | 4 |
| 1-1/2″ | 1.50″ | 6.12″ | 4.50″ | 2.88″ | .250″ | 2.75″ | 1.90″ | 3.00″ | 0.88″ | 2.75″ | 0.88″ | 4 |
| 2″ | 1.94″ | 6.50″ | 5.00″ | 3.62″ | .250″ | 3.31″ | 2.38″ | 3.13″ | 1.00″ | 2.88″ | 0.75″ | 8 |
| 2-1/2″ | 2.32″ | 7.50″ | 5.88″ | 4.12″ | .250″ | 3.94″ | 2.88″ | 3.37″ | 1.12″ | 3.12″ | 0.88″ | 8 |
| 3″ | 2.90″ | 8.25″ | 6.62″ | 5.00″ | .250″ | 4.62″ | 3.50″ | 3.50″ | 1.25″ | 3.25″ | 0.88″ | 8 |
| 3-1/2″ | 3.36″ | 9.00″ | 7.25″ | 5.50″ | .250″ | 5.25″ | 4.00″ | 3.63″ | 1.38″ | 3.38″ | 1.00″ | 8 |
| 4″ | 3.83″ | 10.75″ | 8.50″ | 6.19″ | .250″ | 6.00″ | 4.50″ | 4.25″ | 1.5″ | 4.00″ | 1.00″ | 8 |
| 5″ | 4.81″ | 13.00″ | 10.50″ | 7.31″ | .250″ | 7.44″ | 5.56″ | 4.75″ | 1.75″ | 4.50″ | 1.12″ | 8 |
| 6″ | 5.76″ | 14.00″ | 11.50″ | 8.50″ | .250″ | 8.75″ | 6.63″ | 4.87″ | 1.88″ | 4.62″ | 1.12″ | 12 |
| 8″ | 7.63″ | 16.50″ | 13.75″ | 10.62″ | .250″ | 10.75″ | 8.63″ | 5.50″ | 2.19″ | 5.25″ | 1.25″ | 12 |
| 10″ | 9.75″ | 20.00″ | 17.00″ | 12.75″ | .250″ | 13.5″ | 10.75″ | 6.25″ | 2.50″ | 6.00″ | 1.38″ | 16 |
| 12″ | 11.75″ | 22.00″ | 19.25″ | 15.00″ | .250″ | 15.75″ | 12.75″ | 6.37″ | 2.62″ | 6.12″ | 1.38″ | 20 |
| 14″ | 13.00″ | 23.75″ | 20.75″ | 16.25″ | .250″ | 17.00″ | 14.00″ | 6.75″ | 2.75″ | 6.50″ | 1.50″ | 20 |
| 16″ | 15.00″ | 27.00″ | 23.75″ | 18.50″ | .250″ | 19.50″ | 16.00″ | 7.25″ | 3.00″ | 7.00″ | 1.62″ | 20 |
| 18″ | 17.00″ | 29.25″ | 25.75″ | 21.00″ | .250″ | 21.50″ | 18.00″ | 7.50″ | 3.25″ | 7.25″ | 1.75″ | 20 |
| 20″ | 19.00″ | 32.00″ | 28.50″ | 23.00″ | .250″ | 24.00″ | 20.00″ | 7.75″ | 3.50″ | 7.50″ | 1.75″ | 24 |
| 22″ | 21.00″ | 34.25″ | 30.63″ | 25.25″ | .250″ | 26.25″ | 22.00″ | 8.00″ | 3.75″ | 7.75″ | 1.75″ | 24 |
| 24″ | 23.00″ | 37.00″ | 33.00″ | 27.25″ | .250″ | 28.25″ | 24.00″ | 8.25″ | 4.00″ | 8.00″ | 2.00″ | 24 |
WN CLASS 900 (IN INCH)
Weld neck flange dimensions class 900 (ASME B16.5) in inches

| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3″ | 2.90″ | 9.50″ | 7.50″ | 5.00″ | .250″ | 5.00″ | 3.50″ | 4.25″ | 1.50″ | 4.00″ | 1.00″ | 8 |
| 4″ | 3.83″ | 11.50″ | 9.25″ | 6.19″ | .250″ | 6.25″ | 4.50″ | 4.75″ | 1.75″ | 4.50″ | 1.25″ | 8 |
| 5″ | 4.81″ | 13.75″ | 11.00″ | 7.31″ | .250″ | 7.50″ | 5.56″ | 5.25″ | 3.00″ | 5.00″ | 1.38″ | 8 |
| 6″ | 5.76″ | 15.00″ | 12.50″ | 8.50″ | .250″ | 9.25″ | 6.63″ | 5.75″ | 2.19″ | 5.50″ | 1.25″ | 12 |
| 8″ | 7.63″ | 18.50″ | 15.50″ | 10.63″ | .250″ | 11.75″ | 8.63″ | 6.63″ | 2.50″ | 6.38″ | 1.50″ | 12 |
| 10″ | 9.75″ | 21.50″ | 18.50″ | 12.75″ | .250″ | 14.50″ | 10.75″ | 7.50″ | 2.75″ | 7.25″ | 1.50″ | 16 |
| 12″ | 11.75″ | 24.00″ | 21.00″ | 15.00″ | .250″ | 16.50″ | 12.75″ | 8.13″ | 3.13″ | 7.88″ | 1.50″ | 20 |
| 14″ | 13.00″ | 25.25″ | 22.00″ | 16.25″ | .250″ | 17.75″ | 14.00″ | 8.63″ | 3.38″ | 8.38″ | 1.63″ | 20 |
| 16″ | 15.00″ | 27.75″ | 24.25″ | 18.50″ | .250″ | 20.00″ | 16.00″ | 8.75″ | 3.50″ | 8.50″ | 1.75″ | 20 |
| 18″ | 17.00″ | 31.00″ | 27.00″ | 21.00″ | .250″ | 22.25″ | 18.00″ | 9.25″ | 4.00″ | 9.00″ | 2.00″ | 20 |
| 20″ | 19.00″ | 33.75″ | 29.50″ | 23.00″ | .250″ | 24.50″ | 20.00″ | 10.00″ | 4.25″ | 9.75″ | 2.13″ | 20 |
| 24″ | 23.00″ | 41.00″ | 35.50″ | 27.25″ | .250″ | 29.50″ | 24.00″ | 11.75″ | 5.50″ | 11.50″ | 2.63″ | 20 |
WN CLASS 1500 (IN INCH)
Weld neck flange dimensions class 1500 (ASME B16.5) in inches

| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 0.55″ | 4.75″ | 3.25″ | 1.38″ | .250″ | 1.50″ | 0.84″ | 2.63″ | 0.88″ | 2.38″ | 0.88″ | 4 |
| 3/4″ | 0.74″ | 5.13″ | 3.50″ | 1.69″ | .250″ | 1.75″ | 1.05″ | 3.00″ | 1.00″ | 2.75″ | 0.88″ | 4 |
| 1″ | 0.96″ | 5.88″ | 4.00″ | 2.00″ | .250″ | 2.06″ | 1.32″ | 3.13″ | 1.13″ | 2.88″ | 1.00″ | 4 |
| 1-1/4″ | 1.28″ | 6.25″ | 4.38″ | 2.50″ | .250″ | 2.50″ | 1.66″ | 3.13″ | 1.13″ | 2.88″ | 1.00″ | 4 |
| 1-1/2″ | 1.50″ | 7.00″ | 4.88″ | 2.88″ | .250″ | 2.75″ | 1.90″ | 3.50″ | 1.25″ | 3.25″ | 1.13″ | 4 |
| 2″ | 1.94″ | 8.50″ | 6.50″ | 3.63″ | .250″ | 4.13″ | 2.38″ | 4.25″ | 1.50″ | 4.00″ | 1.00″ | 8 |
| 2-1/2″ | 2.32″ | 9.63″ | 7.50″ | 4.13″ | .250″ | 4.88″ | 2.88″ | 4.38″ | 1.63″ | 4.13″ | 1.13″ | 8 |
| 3″ | 2.90″ | 10.50″ | 8.00″ | 5.00″ | .250″ | 5.25″ | 3.50″ | 4.88″ | 1.88″ | 4.63″ | 1.25″ | 8 |
| 4″ | 3.83″ | 12.25″ | 9.50″ | 6.19″ | .250″ | 6.38″ | 4.50″ | 5.13″ | 2.13″ | 4.88″ | 1.38″ | 8 |
| 5″ | 4.81″ | 14.75″ | 11.50″ | 7.31″ | .250″ | 7.75″ | 5.56″ | 6.38″ | 2.88″ | 6.13″ | 1.63″ | 8 |
| 6″ | 5.76″ | 15.50″ | 12.50″ | 8.50″ | .250″ | 9.00″ | 6.63″ | 7.00″ | 3.25″ | 6.75″ | 1.50″ | 12 |
| 8″ | 7.63″ | 19.00″ | 15.50″ | 10.63″ | .250″ | 11.50″ | 8.63″ | 8.63″ | 3.63″ | 8.38″ | 1.75″ | 12 |
| 10″ | 9.75″ | 23.00″ | 19.00″ | 12.75″ | .250″ | 14.50″ | 10.75″ | 10.25″ | 4.25″ | 10.00″ | 2.00″ | 12 |
| 12″ | 11.75″ | 26.50″ | 22.50″ | 15.00″ | .250″ | 17.75″ | 12.75″ | 11.38″ | 4.88″ | 11.13″ | 2.13″ | 16 |
| 14″ | 13.00″ | 29.50″ | 25.00″ | 16.25″ | .250″ | 19.50″ | 14.00″ | 12.00″ | 5.25″ | 11.75″ | 2.38″ | 16 |
| 16″ | 15.00″ | 32.50″ | 27.75″ | 18.50″ | .250″ | 21.75″ | 16.00″ | 12.50″ | 5.75″ | 12.25″ | 2.63″ | 16 |
| 18″ | 17.00″ | 36.00″ | 30.50″ | 21.00″ | .250″ | 23.50″ | 18.00″ | 13.13″ | 6.38″ | 12.88″ | 2.88″ | 16 |
| 20″ | 19.00″ | 38.75″ | 32.75″ | 23.00″ | .250″ | 25.25″ | 20.00″ | 14.25″ | 7.00″ | 14.00″ | 3.13″ | 16 |
| 24″ | 23.00″ | 46.00″ | 39.00″ | 27.25″ | .250″ | 30.00″ | 24.00″ | 16.25″ | 8.00″ | 16.00″ | 3.63″ | 16 |
WN CLASS 2500 (IN INCH)
Weld neck flange dimensions class 2500 (ASME B16.5) in inches

| Flange NPS | Inside Diameter | Outside Diameter | Bolt Circle (BC) | Raised Face (R) | Raised Face (RF) | H | H1 | Raised Face Thickness (T) | T1 | Flat Face Thickness (T2) | Bolt Hole (B) | No. of Bolt Holes |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 0.55″ | 5.25″ | 3.50″ | 1.38″ | .250″ | 1.69″ | 0.84″ | 3.13″ | 1.19″ | 2.88″ | 0.88″ | 4 |
| 3/4″ | 0.74″ | 5.50″ | 3.75″ | 1.69″ | .250″ | 2.00″ | 1.05″ | 3.38″ | 1.25″ | 3.13″ | 0.88″ | 4 |
| 1″ | 0.96″ | 6.25″ | 4.25″ | 2.00″ | .250″ | 2.25″ | 1.32″ | 3.75″ | 1.38″ | 3.50″ | 1.00″ | 4 |
| 1-1/4″ | 1.28″ | 7.25″ | 5.13″ | 2.50″ | .250″ | 2.88″ | 1.66″ | 4.00″ | 1.50″ | 3.75″ | 1.13″ | 4 |
| 1-1/2″ | 1.50″ | 8.00″ | 5.75″ | 2.88″ | .250″ | 3.13″ | 1.90″ | 4.63″ | 1.75″ | 4.38″ | 1.25″ | 4 |
| 2″ | 1.94″ | 9.25″ | 6.75″ | 3.63″ | .250″ | 3.75″ | 2.38″ | 5.25″ | 2.00″ | 5.00″ | 1.13″ | 8 |
| 2-1/2″ | 2.32″ | 10.50″ | 7.75″ | 4.13″ | .250″ | 4.50″ | 2.88″ | 5.88″ | 2.25″ | 5.63″ | 1.25″ | 8 |
| 3″ | 2.90″ | 12.00″ | 9.00″ | 5.00″ | .250″ | 5.25″ | 3.50″ | 6.88″ | 2.63″ | 6.63″ | 1.38″ | 8 |
| 4″ | 3.83″ | 14.00″ | 10.75″ | 6.19″ | .250″ | 6.50″ | 4.50″ | 7.75″ | 3.00″ | 7.50″ | 1.63″ | 8 |
| 5″ | 4.81″ | 16.50″ | 12.75″ | 7.31″ | .250″ | 8.00″ | 5.56″ | 9.25″ | 3.63″ | 9.00″ | 1.88″ | 8 |
| 6″ | 5.76″ | 19.00″ | 14.50″ | 8.50″ | .250″ | 9.25″ | 6.63″ | 11.00″ | 4.25″ | 10.75″ | 2.13″ | 8 |
| 8″ | 7.63″ | 21.75″ | 17.25″ | 10.63″ | .250″ | 12.00″ | 8.63″ | 12.75″ | 5.00″ | 12.50″ | 2.13″ | 12 |
| 10″ | 9.75″ | 26.50″ | 21.25″ | 12.75″ | .250″ | 14.75″ | 10.75″ | 16.75″ | 6.50″ | 16.50″ | 2.63″ | 12 |
| 12″ | 11.75″ | 30.00″ | 24.38″ | 15.00″ | .250″ | 17.38″ | 12.75″ | 18.50″ | 7.25″ | 18.25″ | 2.88″ | 12 |



