Industry Standard Welding Neck Flanges
Class 175
| NPS | Outside Diameter of Flange | Thickness of Flange | Length thru Hub | Diameter of Hub at Base | Diameter of Raised Face | Diameter of Bolt Circle | No. of Bolt Holes | Diameter of Bolt Holes | ||
| WNF | BLIND | |||||||||
| A | O | C | C | Y | X | R | ||||
| 26 | in. | 31.5 | 1.38 | 1.81 | 3.38 | 27.63 | 29 | 29.88 | 28 | 0.88 |
| mm | 800.1 | 35.1 | 46 | 85.9 | 701.8 | 736.6 | 759 | 22.4 | ||
| 28 | in. | 33.5 | 1.38 | 1.88 | 3.38 | 29.63 | 31 | 31.88 | 28 | 0.88 |
| mm | 850.9 | 35.1 | 47.8 | 85.9 | 752.6 | 787.4 | 809.8 | 22.4 | ||
| 30 | in. | 35.75 | 1.38 | 2 | 3.63 | 31.88 | 33.25 | 34.13 | 36 | 0.88 |
| mm | 908 | 35.1 | 50.8 | 92.2 | 809.8 | 844.5 | 866.9 | 22.4 | ||
| 32 | in. | 37.75 | 1.38 | 2.12 | 3.63 | 33.88 | 35.25 | 36.13 | 36 | 0.88 |
| mm | 958.8 | 35.1 | 53.8 | 92.2 | 860.6 | 895.3 | 917.7 | 22.4 | ||
| 34 | in. | 40.25 | 1.5 | 2.25 | 3.75 | 35.88 | 38.38 | 38.38 | 36 | 1 |
| mm | 1022.3 | 38.1 | 57.1 | 95.3 | 911.4 | 949.5 | 974.9 | 25.4 | ||
| 36 | in. | 42.25 | 1.5 | 2.38 | 3.75 | 37.88 | 39.38 | 40.38 | 36 | 1 |
| mm | 1073.1 | 38.1 | 60.5 | 95.3 | 962.2 | 1000.3 | 1025.7 | 25.4 | ||
| 38 | in. | 44.25 | 1.75 | 2.5 | 4.13 | 39.88 | 41.38 | 42.38 | 36 | 1 |
| mm | 1124 | 44.4 | 63.5 | 104.9 | 1013 | 1051.1 | 1076.5 | 25.4 | ||
| 40 | in. | 46.25 | 1.75 | 2.62 | 4.13 | 41.88 | 43.38 | 44.38 | 40 | 1 |
| mm | 1174.8 | 44.4 | 66.5 | 104.9 | 1063.8 | 1101.9 | 1127.3 | 25.4 | ||
| 42 | in. | 49 | 2 | 2.75 | 4.5 | 44.13 | 45.75 | 46.88 | 40 | 1.13 |
| mm | 1244.6 | 50.8 | 69.8 | 114.3 | 1120.9 | 1162.1 | 1190.8 | 28.7 | ||
| 44 | in. | 51 | 2 | 2.88 | 4.5 | 46.13 | 47.75 | 48.88 | 40 | 1.13 |
| mm | 1295.4 | 50.8 | 73.2 | 114.3 | 1171.7 | 1212.8 | 1241.6 | 28.7 | ||
| 46 | in. | 53 | 2 | 3 | 4.5 | 48.13 | 49.75 | 50.88 | 40 | 1.13 |
| mm | 1346.2 | 50.8 | 76.2 | 114.3 | 1222.5 | 1263.6 | 1292.4 | 28.7 | ||
| 48 | in. | 55 | 2.25 | 3.12 | 4.88 | 50.13 | 51.75 | 52.88 | 44 | 1.13 |
| mm | 1397 | 57.1 | 79.2 | 124 | 1273.3 | 1314.4 | 1343.2 | 28.7 | ||
| 50 | in. | 57 | 2.25 | 3.25 | 4.88 | 52.13 | 53.75 | 54.88 | 44 | 1.13 |
| mm | 1447.8 | 57.1 | 82.5 | 124 | 1324.1 | 1365.3 | 1394.3 | 28.7 | ||
| 52 | in. | 59.5 | 2.63 | 3.38 | 5.38 | 54.25 | 56 | 57.25 | 44 | 1.25 |
| mm | 1511.3 | 66.8 | 85.9 | 136.7 | 1377.9 | 1422.4 | 1454.1 | 31.8 | ||
| 54 | in. | 61.5 | 2.63 | 3.5 | 5.38 | 56.25 | 58 | 59.25 | 44 | 1.25 |
| mm | 1562.1 | 66.8 | 88.9 | 136.7 | 1428.8 | 1473.2 | 1504.9 | 31.8 | ||
| 60 | in. | 67.5 | 2.75 | 3.88 | 5.75 | 62.25 | 61 | 65.25 | 48 | 1.25 |
| mm | 1714.5 | 69.8 | 98.6 | 146 | 1581.1 | 1625.6 | 1657.3 | 31.8 | ||
| 66 | in. | 73.5 | 3.13 | 4.25 | 6.13 | 68.5 | 70 | 71.25 | 56 | 1.25 |
| mm | 1866.9 | 79.5 | 107.9 | 155.7 | 1739.9 | 1778 | 1809.8 | 31.8 | ||
| 72 | in. | 80 | 3.63 | 4.5 | 6.63 | 74.5 | 76.5 | 77.75 | 64 | 1.25 |
| mm | 2032 | 92.2 | 114.3 | 168.4 | 1892.3 | 1943.1 | 1974.8 | 31.8 |