Welding Neck Flanges
Class 300
| Nominal size | O | C | R | X | A | Y | No. of holes | Diam. of holes | Diam. of bolts | Diam. of bolt circle | Approx. weight pounds Kg | |
| O | C | R | X | A | Y | |||||||
| in. | 1/2″ | 3.75 | 0.56 | 1.38 | 1.5 | 0.84 | 2.06 | 4 | 0.62 | 1/2″ | 2.62 | 2 |
| mm. | 95.3 | 14.2 | 35.1 | 38.1 | 21.3 | 52.3 | 15.7 | 12.7 | 66.5 | 1 | ||
| in. | 3/4″ | 4.62 | 0.62 | 1.69 | 1.88 | 1.05 | 2.25 | 4 | 0.75 | 5/8″ | 3.25 | 3 |
| mm. | 117.3 | 15.7 | 42.9 | 47.8 | 26.7 | 57.2 | 19.1 | 15.9 | 82.6 | 1 | ||
| in. | 1″ | 4.88 | 0.69 | 2 | 2.12 | 1.32 | 2.44 | 4 | 0.75 | 5/8″ | 3.5 | 4 |
| mm. | 124 | 17.5 | 50.8 | 53.8 | 33.5 | 62 | 19.1 | 15.9 | 88.9 | 2 | ||
| in. | 1 1/4″ | 5.25 | 0.75 | 2.5 | 2.5 | 1.66 | 2.56 | 4 | 0.75 | 5/8″ | 3.88 | 5 |
| mm. | 133.4 | 19.1 | 63.5 | 63.5 | 42.2 | 65 | 19.1 | 15.9 | 98.6 | 2 | ||
| in. | 1 1/2″ | 6.12 | 0.81 | 2.88 | 2.75 | 1.9 | 2.69 | 4 | 0.88 | 3/4″ | 4.5 | 7 |
| mm. | 155.4 | 20.6 | 73.2 | 69.9 | 48.3 | 68.3 | 22.4 | 19.1 | 114.3 | 3 | ||
| in. | 2″ | 6.5 | 0.88 | 3.62 | 3.31 | 2.38 | 2.75 | 8 | 0.75 | 5/8″ | 5 | 9 |
| mm. | 165.1 | 22.4 | 91.9 | 84.1 | 60.5 | 69.9 | 19.1 | 15.9 | 127 | 4 | ||
| in. | 2 1/2″ | 7.5 | 1 | 4.12 | 3.94 | 2.88 | 3 | 8 | 0.88 | 3/4″ | 5.88 | 12 |
| mm. | 190.5 | 25.4 | 104.6 | 100.1 | 73.2 | 76.2 | 22.4 | 19.1 | 149.4 | 5 | ||
| in. | 3″ | 8.25 | 1.12 | 5 | 4.62 | 3.5 | 3.12 | 8 | 0.88 | 3/4″ | 6.62 | 15 |
| mm. | 209.6 | 28.4 | 127 | 117.3 | 88.9 | 79.2 | 22.4 | 19.1 | 168.1 | 7 | ||
| in. | 3 1/2″ | 9 | 1.19 | 5.5 | 5.25 | 4 | 3.19 | 8 | 0.88 | 3/4″ | 7.25 | 18 |
| mm. | 228.6 | 30.2 | 139.7 | 133.4 | 101.6 | 81 | 22.4 | 19.1 | 184.2 | 8 | ||
| in. | 4″ | 10 | 1.25 | 6.19 | 5.75 | 4.5 | 3.38 | 8 | 0.88 | 3/4″ | 7.88 | 25 |
| mm. | 254 | 31.8 | 157.2 | 146.1 | 114.3 | 85.9 | 22.4 | 19.1 | 200.2 | 11 | ||
| in. | 5″ | 11 | 1.38 | 7.31 | 7 | 5.56 | 3.88 | 8 | 0.88 | 3/4″ | 9.25 | 32 |
| mm. | 279.4 | 35.1 | 185.7 | 177.8 | 141.2 | 98.6 | 22.4 | 19.1 | 235 | 15 | ||
| in. | 6″ | 12.5 | 1.44 | 8.5 | 8.12 | 6.63 | 3.88 | 12 | 0.88 | 3/4″ | 10.62 | 42 |
| mm. | 317.5 | 36.6 | 215.9 | 206.2 | 168.4 | 98.6 | 22.4 | 19.1 | 269.7 | 19 | ||
| in. | 8″ | 15 | 1.62 | 10.62 | 10.25 | 8.63 | 4.38 | 12 | 1 | 7/8″ | 13 | 67 |
| mm. | 381 | 41.1 | 269.7 | 260.4 | 219.2 | 111.3 | 25.4 | 22.2 | 330.2 | 30 | ||
| in. | 10″ | 17.5 | 1.88 | 12.75 | 12.62 | 10.75 | 4.62 | 16 | 1.12 | 1″ | 15.25 | 91 |
| mm. | 444.5 | 47.8 | 323.9 | 320.5 | 273.1 | 117.3 | 28.4 | 25.4 | 387.4 | 41 | ||
| in. | 12″ | 20.5 | 2 | 15 | 14.75 | 12.75 | 5.12 | 16 | 1.25 | 1 1/8″ | 17.75 | 140 |
| mm. | 520.7 | 50.8 | 381 | 374.7 | 323.9 | 130 | 31.8 | 28.6 | 450.9 | 64 | ||
| in. | 14″ | 23 | 2.12 | 16.25 | 16.75 | 14 | 5.62 | 20 | 1.25 | 1 1/8″ | 20.25 | 180 |
| mm. | 584.2 | 53.8 | 412.8 | 425.5 | 355.6 | 142.7 | 31.8 | 28.6 | 514.4 | 82 | ||
| in. | 16″ | 25.5 | 2.25 | 18.5 | 19 | 16 | 5.75 | 20 | 1.38 | 1 1/4″ | 22.5 | 250 |
| mm. | 647.7 | 57.2 | 469.9 | 482.6 | 406.4 | 146.1 | 35.1 | 31.8 | 571.5 | 113 | ||
| in. | 18″ | 28 | 2.38 | 21 | 21 | 18 | 6.25 | 24 | 1.38 | 1 1/4″ | 24.75 | 320 |
| mm. | 711.2 | 60.5 | 533.4 | 533.4 | 457.2 | 158.8 | 35.1 | 31.8 | 628.7 | 145 | ||
| in. | 20″ | 30.5 | 2.5 | 23 | 23.12 | 20 | 6.38 | 24 | 1.38 | 1 1/4″ | 27 | 400 |
| mm. | 774.7 | 63.5 | 584.2 | 587.2 | 508 | 162.1 | 35.1 | 31.8 | 685.8 | 181 | ||
| in. | 24″ | 36 | 2.75 | 27.25 | 27.62 | 24 | 6.62 | 24 | 1.62 | 1 1/2″ | 32 | 580 |
| mm. | 914.4 | 69.9 | 692.2 | 701.5 | 609.6 | 168.1 | 41.1 | 38.1 | 812.8 | 263 |