ASME B16.5 · B16.47 · JIS B2220 · EN 1092-1
Weld Neck Flange Manufacturer — ASME B16.5, B16.47, JIS B2220, EN 1092-1
Weld neck flanges are the default specification for high-pressure, high-temperature and cyclic-service piping because the tapered hub moves stress away from the weld and the butt weld can be fully radiographed.
Standard
ASME B16.5 / B16.47 / JIS B2220 / EN 1092-1
Size range
1/2″–60″ (ASME) · 10A–600A (JIS) · DN10–DN600 (EN)
Pressure class
Class 150–2500 · 5K–30K · PN6–PN40
Materials
A105, A350 LF2, A182 F304/F316, F11/F22/F91, 2205
Faces
RF, FF, RTJ
Finish
125–250 AARH, or per drawing
A weld neck flange (WN) connects to pipe with a single full-penetration butt weld. The long tapered hub transitions thickness gradually from the pipe wall to the flange ring, which lowers local stress concentration and improves fatigue life compared with slip-on or socket-weld designs. Because the bore matches the pipe schedule, there is no internal ledge for turbulence, erosion or crevice corrosion — a decisive advantage in wet sour service and in lines that are pigged or inspected by intelligent tools.
We machine weld neck flanges to ASME B16.5 (1/2″–24″) and ASME B16.47 Series A and B (26″–60″) in carbon steel, stainless steel, alloy steel and duplex grades. JIS B2220 weld necks (10A–600A, 5K–30K) and EN 1092-1 type 11 weld necks (DN10–DN600, PN6–PN40) are machined to the same inspection standard. Standard pressure classes are 150, 300, 600, 900, 1500 and 2500 with raised face (RF), flat face (FF) and ring-type joint (RTJ) finishes. Every flange is supplied with a heat number stamped on the rim, a dimensioned inspection report and a 3.1 material certificate so the receiving engineer can trace the part back to the heat and the mechanical test results.
Dimensions by standard — ASME, JIS and EN
Each table is the published dimension record for one standard and rating. ASME values are shown in millimetres with the inch equivalent; JIS B2220 and EN 1092-1 values are metric as published. Flange thickness excludes the raised-face height (1.5 mm for ASME B16.5 Classes 150/300, 6.4 mm for Classes 400–2500, 1.5 mm for B16.47 Classes 75/150/300 and 6.4 mm for Classes 400–900, 2 mm for JIS/EN). A size link opens the full specification page for that size and rating.
ASME B16.5
ASME B16.5-2025 · North America, Middle East, South-East Asia
weld neck flange · Class 150
| Size | DN | OD | Thickness | RF Ø | Bolt circle | Bolts | Hub Ø | Length | Weight | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 15 | 88.9 mm (3.5″) | 9.7 mm (0.38″) | 35.1 mm (1.38″) | 60.5 mm (2.38″) | 4 × Ø15.9 mm (0.63″) | 30.2 mm (1.19″) | 46 mm (1.81″) | 0.9 kg | Details → |
| 3/4″ | 20 | 98.6 mm (3.88″) | 11.2 mm (0.44″) | 42.9 mm (1.69″) | 69.9 mm (2.75″) | 4 × Ø15.9 mm (0.63″) | 38.1 mm (1.5″) | 50.8 mm (2″) | 0.9 kg | Details → |
| 1″ | 25 | 108 mm (4.25″) | 12.7 mm (0.5″) | 50.8 mm (2″) | 79.2 mm (3.12″) | 4 × Ø15.9 mm (0.63″) | 49.3 mm (1.94″) | 53.8 mm (2.12″) | 1.4 kg | Details → |
| 1¼″ | 32 | 117.3 mm (4.62″) | 14.2 mm (0.56″) | 63.5 mm (2.5″) | 88.9 mm (3.5″) | 4 × Ø15.9 mm (0.63″) | 58.7 mm (2.31″) | 55.6 mm (2.19″) | 1.4 kg | Details → |
| 1½″ | 40 | 127 mm (5″) | 15.7 mm (0.62″) | 73.2 mm (2.88″) | 98.6 mm (3.88″) | 4 × Ø15.9 mm (0.63″) | 65 mm (2.56″) | 60.5 mm (2.38″) | 1.8 kg | Details → |
| 2″ | 50 | 152.4 mm (6″) | 17.5 mm (0.69″) | 91.9 mm (3.62″) | 120.7 mm (4.75″) | 4 × Ø19.1 mm (0.75″) | 77.7 mm (3.06″) | 62 mm (2.44″) | 2.7 kg | Details → |
| 2½″ | 65 | 177.8 mm (7″) | 20.6 mm (0.81″) | 104.6 mm (4.12″) | 139.7 mm (5.5″) | 4 × Ø19.1 mm (0.75″) | 90.4 mm (3.56″) | 68.3 mm (2.69″) | 3.6 kg | Details → |
| 3″ | 80 | 190.5 mm (7.5″) | 22.4 mm (0.88″) | 127 mm (5″) | 152.4 mm (6″) | 4 × Ø19.1 mm (0.75″) | 108 mm (4.25″) | 68.3 mm (2.69″) | 4.5 kg | Details → |
| 3½″ | 90 | 215.9 mm (8.5″) | 22.4 mm (0.88″) | 139.7 mm (5.5″) | 177.8 mm (7″) | 8 × Ø19.1 mm (0.75″) | 122.2 mm (4.81″) | 69.9 mm (2.75″) | 5.4 kg | Details → |
| 4″ | 100 | 228.6 mm (9″) | 22.4 mm (0.88″) | 157.2 mm (6.19″) | 190.5 mm (7.5″) | 8 × Ø19.1 mm (0.75″) | 134.9 mm (5.31″) | 74.7 mm (2.94″) | 6.8 kg | Details → |
| 5″ | 125 | 254 mm (10″) | 22.4 mm (0.88″) | 185.7 mm (7.31″) | 215.9 mm (8.5″) | 8 × Ø22.2 mm (0.87″) | 163.6 mm (6.44″) | 87.4 mm (3.44″) | 8.6 kg | Details → |
| 6″ | 150 | 279.4 mm (11″) | 23.9 mm (0.94″) | 215.9 mm (8.5″) | 241.3 mm (9.5″) | 8 × Ø22.2 mm (0.87″) | 192 mm (7.56″) | 87.4 mm (3.44″) | 10.9 kg | Details → |
| 8″ | 200 | 342.9 mm (13.5″) | 26.9 mm (1.06″) | 269.7 mm (10.62″) | 298.5 mm (11.75″) | 8 × Ø22.2 mm (0.87″) | 246.1 mm (9.69″) | 100.1 mm (3.94″) | 17.7 kg | Details → |
| 10″ | 250 | 406.4 mm (16″) | 28.4 mm (1.12″) | 323.9 mm (12.75″) | 362 mm (14.25″) | 12 × Ø25.4 mm (1″) | 304.8 mm (12″) | 100.1 mm (3.94″) | 23.6 kg | Details → |
| 12″ | 300 | 482.6 mm (19″) | 30.2 mm (1.19″) | 381 mm (15″) | 431.8 mm (17″) | 12 × Ø25.4 mm (1″) | 365.3 mm (14.38″) | 112.8 mm (4.44″) | 36.3 kg | Details → |
| 14″ | 350 | 533.4 mm (21″) | 33.3 mm (1.31″) | 412.8 mm (16.25″) | 476.3 mm (18.75″) | 12 × Ø28.6 mm (1.13″) | 400.1 mm (15.75″) | 125.5 mm (4.94″) | 49.9 kg | Details → |
| 16″ | 400 | 596.9 mm (23.5″) | 35.1 mm (1.38″) | 469.9 mm (18.5″) | 539.8 mm (21.25″) | 16 × Ø28.6 mm (1.13″) | 457.2 mm (18″) | 125.5 mm (4.94″) | 63.5 kg | Details → |
| 18″ | 450 | 635 mm (25″) | 38.1 mm (1.5″) | 533.4 mm (21″) | 577.9 mm (22.75″) | 16 × Ø31.8 mm (1.25″) | 505 mm (19.88″) | 138.2 mm (5.44″) | 68 kg | Details → |
| 20″ | 500 | 698.5 mm (27.5″) | 41.1 mm (1.62″) | 584.2 mm (23″) | 635 mm (25″) | 20 × Ø31.8 mm (1.25″) | 558.8 mm (22″) | 142.7 mm (5.62″) | 81.6 kg | Details → |
| 22″ | 550 | 749.3 mm (29.5″) | 44.5 mm (1.75″) | 641.4 mm (25.25″) | 692.2 mm (27.25″) | 20 × Ø28.6 mm (1.13″) | 609.6 mm (24″) | 147.8 mm (5.82″) | — | Details → |
| 24″ | 600 | 812.8 mm (32″) | 46 mm (1.81″) | 692.2 mm (27.25″) | 749.3 mm (29.5″) | 20 × Ø34.9 mm (1.37″) | 663.4 mm (26.12″) | 150.9 mm (5.94″) | 118 kg | Details → |
weld neck flange · Class 300
| Size | DN | OD | Thickness | RF Ø | Bolt circle | Bolts | Hub Ø | Length | Weight | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1/2″ | 15 | 95.3 mm (3.75″) | 12.7 mm (0.5″) | 35.1 mm (1.38″) | 66.5 mm (2.62″) | 4 × Ø15.9 mm (0.63″) | 38.1 mm (1.5″) | 50.8 mm (2″) | 0.9 kg | Details → |
| 3/4″ | 20 | 117.3 mm (4.62″) | 14.2 mm (0.56″) | 42.9 mm (1.69″) | 82.6 mm (3.25″) | 4 × Ø19.1 mm (0.75″) | 47.8 mm (1.88″) | 55.6 mm (2.19″) | 1.4 kg | Details → |
| 1″ | 25 | 124 mm (4.88″) | 15.7 mm (0.62″) | 50.8 mm (2″) | 88.9 mm (3.5″) | 4 × Ø19.1 mm (0.75″) | 53.8 mm (2.12″) | 60.5 mm (2.38″) | 1.8 kg | Details → |
| 1¼″ | 32 | 133.4 mm (5.25″) | 17.5 mm (0.69″) | 63.5 mm (2.5″) | 98.6 mm (3.88″) | 4 × Ø19.1 mm (0.75″) | 63.5 mm (2.5″) | 63.5 mm (2.5″) | 2.3 kg | Details → |
| 1½″ | 40 | 155.4 mm (6.12″) | 19.1 mm (0.75″) | 73.2 mm (2.88″) | 114.3 mm (4.5″) | 4 × Ø22.2 mm (0.87″) | 69.9 mm (2.75″) | 66.8 mm (2.63″) | 3.2 kg | Details → |
| 2″ | 50 | 165.1 mm (6.5″) | 20.6 mm (0.81″) | 91.9 mm (3.62″) | 127 mm (5″) | 8 × Ø19.1 mm (0.75″) | 84.1 mm (3.31″) | 68.3 mm (2.69″) | 4.1 kg | Details → |
| 2½″ | 65 | 190.5 mm (7.5″) | 23.9 mm (0.94″) | 104.6 mm (4.12″) | 149.4 mm (5.88″) | 8 × Ø22.2 mm (0.87″) | 100.1 mm (3.94″) | 74.7 mm (2.94″) | 5.4 kg | Details → |
| 3″ | 80 | 209.6 mm (8.25″) | 26.9 mm (1.06″) | 127 mm (5″) | 168.1 mm (6.62″) | 8 × Ø22.2 mm (0.87″) | 117.3 mm (4.62″) | 77.7 mm (3.06″) | 6.8 kg | Details → |
| 3½″ | 90 | 228.6 mm (9″) | 28.4 mm (1.12″) | 139.7 mm (5.5″) | 184.2 mm (7.25″) | 8 × Ø22.2 mm (0.87″) | 133.4 mm (5.25″) | 79.5 mm (3.13″) | 8.2 kg | Details → |
| 4″ | 100 | 254 mm (10″) | 30.2 mm (1.19″) | 157.2 mm (6.19″) | 200.2 mm (7.88″) | 8 × Ø22.2 mm (0.87″) | 146.1 mm (5.75″) | 84.3 mm (3.32″) | 11.3 kg | Details → |
| 5″ | 125 | 279.4 mm (11″) | 33.3 mm (1.31″) | 185.7 mm (7.31″) | 235 mm (9.25″) | 8 × Ø22.2 mm (0.87″) | 177.8 mm (7″) | 97 mm (3.82″) | 14.5 kg | Details → |
| 6″ | 150 | 317.5 mm (12.5″) | 35.1 mm (1.38″) | 215.9 mm (8.5″) | 269.7 mm (10.62″) | 12 × Ø22.2 mm (0.87″) | 206.2 mm (8.12″) | 97 mm (3.82″) | 19.1 kg | Details → |
| 8″ | 200 | 381 mm (15″) | 39.6 mm (1.56″) | 269.7 mm (10.62″) | 330.2 mm (13″) | 12 × Ø25.4 mm (1″) | 260.4 mm (10.25″) | 109.7 mm (4.32″) | 30.4 kg | Details → |
| 10″ | 250 | 444.5 mm (17.5″) | 46 mm (1.81″) | 323.9 mm (12.75″) | 387.4 mm (15.25″) | 16 × Ø28.6 mm (1.13″) | 320.5 mm (12.62″) | 115.8 mm (4.56″) | 41.3 kg | Details → |
| 12″ | 300 | 520.7 mm (20.5″) | 49.3 mm (1.94″) | 381 mm (15″) | 450.9 mm (17.75″) | 16 × Ø31.8 mm (1.25″) | 374.7 mm (14.75″) | 128.5 mm (5.06″) | 63.5 kg | Details → |
| 14″ | 350 | 584.2 mm (23″) | 52.3 mm (2.06″) | 412.8 mm (16.25″) | 514.4 mm (20.25″) | 20 × Ø31.8 mm (1.25″) | 425.5 mm (16.75″) | 141.2 mm (5.56″) | 81.6 kg | Details → |
| 16″ | 400 | 647.7 mm (25.5″) | 55.6 mm (2.19″) | 469.9 mm (18.5″) | 571.5 mm (22.5″) | 20 × Ø34.9 mm (1.37″) | 482.6 mm (19″) | 144.5 mm (5.69″) | 113 kg | Details → |
| 18″ | 450 | 711.2 mm (28″) | 58.7 mm (2.31″) | 533.4 mm (21″) | 628.7 mm (24.75″) | 24 × Ø34.9 mm (1.37″) | 533.4 mm (21″) | 157.2 mm (6.19″) | 145 kg | Details → |
| 20″ | 500 | 774.7 mm (30.5″) | 62 mm (2.44″) | 584.2 mm (23″) | 685.8 mm (27″) | 24 × Ø34.9 mm (1.37″) | 587.2 mm (23.12″) | 160.5 mm (6.32″) | 181 kg | Details → |
| 22″ | 550 | 838.2 mm (33″) | 65 mm (2.56″) | 641.4 mm (25.25″) | 743 mm (29.25″) | 24 × Ø41.3 mm (1.63″) | 641.4 mm (25.25″) | 163.6 mm (6.44″) | — | Details → |
| 24″ | 600 | 914.4 mm (36″) | 68.3 mm (2.69″) | 692.2 mm (27.25″) | 812.8 mm (32″) | 24 × Ø41.3 mm (1.63″) | 701.5 mm (27.62″) | 166.6 mm (6.56″) | 263 kg | Details → |
ASME B16.47 Series A
ASME B16.47-2025, Series A · North America, Middle East
weld neck flange · Class 150
| Size | DN | OD | Thickness | RF Ø | Bolt circle | Bolts | Hub Ø | Length | Weight | |
|---|---|---|---|---|---|---|---|---|---|---|
| 26″ | 650 | 870 mm (34.25″) | 66.8 mm (2.63″) | 749 mm (29.49″) | 806.4 mm (31.75″) | 24 × Ø34.9 mm (1.37″) | 676 mm (26.61″) | 119 mm (4.69″) | 136 kg | Details → |
| 28″ | 700 | 927 mm (36.5″) | 69.8 mm (2.75″) | 800 mm (31.5″) | 863.6 mm (34″) | 28 × Ø34.9 mm (1.37″) | 727 mm (28.62″) | 124 mm (4.88″) | 156 kg | Details → |
| 30″ | 750 | 984 mm (38.74″) | 73.2 mm (2.88″) | 857 mm (33.74″) | 914.4 mm (36″) | 28 × Ø34.9 mm (1.37″) | 781 mm (30.75″) | 135 mm (5.31″) | 181 kg | Details → |
| 32″ | 800 | 1060 mm (41.73″) | 79.5 mm (3.13″) | 914 mm (35.98″) | 977.9 mm (38.5″) | 28 × Ø41.3 mm (1.63″) | 832 mm (32.76″) | 143 mm (5.63″) | 229 kg | Details → |
| 34″ | 850 | 1111 mm (43.74″) | 81 mm (3.19″) | 965 mm (37.99″) | 1028.7 mm (40.5″) | 32 × Ø41.3 mm (1.63″) | 883 mm (34.76″) | 148 mm (5.83″) | 245 kg | Details → |
| 36″ | 900 | 1168 mm (45.98″) | 88.9 mm (3.5″) | 1022 mm (40.24″) | 1085.8 mm (42.75″) | 32 × Ø41.3 mm (1.63″) | 933 mm (36.73″) | 156 mm (6.14″) | 290 kg | Details → |
| 38″ | 950 | 1238 mm (48.74″) | 85.9 mm (3.38″) | 1073 mm (42.24″) | 1149.4 mm (45.25″) | 32 × Ø41.3 mm (1.63″) | 991 mm (39.02″) | 156 mm (6.14″) | 327 kg | Details → |
| 40″ | 1000 | 1289 mm (50.75″) | 88.9 mm (3.5″) | 1124 mm (44.25″) | 1200.2 mm (47.25″) | 36 × Ø41.3 mm (1.63″) | 1041 mm (40.98″) | 162 mm (6.38″) | 352 kg | Details → |
| 42″ | 1050 | 1346 mm (52.99″) | 95.2 mm (3.75″) | 1194 mm (47.01″) | 1257.3 mm (49.5″) | 36 × Ø41.3 mm (1.63″) | 1092 mm (42.99″) | 170 mm (6.69″) | 404 kg | Details → |
| 44″ | 1100 | 1403 mm (55.24″) | 100.1 mm (3.94″) | 1245 mm (49.02″) | 1314.4 mm (51.75″) | 40 × Ø41.3 mm (1.63″) | 1143 mm (45″) | 176 mm (6.93″) | 449 kg | Details → |
| 46″ | 1150 | 1454 mm (57.24″) | 101.6 mm (4″) | 1295 mm (50.98″) | 1365.2 mm (53.75″) | 40 × Ø41.3 mm (1.63″) | 1197 mm (47.13″) | 184 mm (7.24″) | 481 kg | Details → |
| 48″ | 1200 | 1511 mm (59.49″) | 106.4 mm (4.19″) | 1359 mm (53.5″) | 1422.4 mm (56″) | 44 × Ø41.3 mm (1.63″) | 1248 mm (49.13″) | 191 mm (7.52″) | 538 kg | Details → |
| 50″ | 1250 | 1568 mm (61.73″) | 109.7 mm (4.32″) | 1410 mm (55.51″) | 1479.6 mm (58.25″) | 44 × Ø47.6 mm (1.87″) | 1302 mm (51.26″) | 202 mm (7.95″) | 576 kg | Details → |
| 52″ | 1300 | 1626 mm (64.02″) | 114.3 mm (4.5″) | 1461 mm (57.52″) | 1536.7 mm (60.5″) | 44 × Ø47.6 mm (1.87″) | 1353 mm (53.27″) | 208 mm (8.19″) | 640 kg | Details → |
| 54″ | 1350 | 1683 mm (66.26″) | 119.1 mm (4.69″) | 1511 mm (59.49″) | 1593.8 mm (62.75″) | 44 × Ø47.6 mm (1.87″) | 1403 mm (55.24″) | 214 mm (8.43″) | 719 kg | Details → |
| 56″ | 1400 | 1746 mm (68.74″) | 122.4 mm (4.82″) | 1575 mm (62.01″) | 1651 mm (65″) | 48 × Ø47.6 mm (1.87″) | 1457 mm (57.36″) | 227 mm (8.94″) | 798 kg | Details → |
| 58″ | 1450 | 1803 mm (70.98″) | 127 mm (5″) | 1626 mm (64.02″) | 1708.2 mm (67.25″) | 48 × Ø47.6 mm (1.87″) | 1508 mm (59.37″) | 233 mm (9.17″) | 869 kg | Details → |
| 60″ | 1500 | 1854 mm (72.99″) | 130.3 mm (5.13″) | 1676 mm (65.98″) | 1759 mm (69.25″) | 52 × Ø47.6 mm (1.87″) | 1559 mm (61.38″) | 238 mm (9.37″) | 928 kg | Details → |
ASME B16.47 Series B
ASME B16.47-2025, Series B · North America, Middle East
weld neck flange · Class 150
| Size | DN | OD | Thickness | RF Ø | Bolt circle | Bolts | Hub Ø | Length | Weight | |
|---|---|---|---|---|---|---|---|---|---|---|
| 26″ | 650 | 786 mm (30.94″) | 39.9 mm (1.57″) | 711 mm (27.99″) | 744.5 mm (29.31″) | 36 × Ø22.2 mm (0.87″) | 684 mm (26.93″) | 87 mm (3.43″) | 54.4 kg | Details → |
| 28″ | 700 | 837 mm (32.95″) | 42.9 mm (1.69″) | 762 mm (30″) | 795.3 mm (31.31″) | 40 × Ø22.2 mm (0.87″) | 735 mm (28.94″) | 94 mm (3.7″) | 63.5 kg | Details → |
| 30″ | 750 | 887 mm (34.92″) | 42.9 mm (1.69″) | 813 mm (32.01″) | 846.1 mm (33.31″) | 44 × Ø22.2 mm (0.87″) | 787 mm (30.98″) | 98 mm (3.86″) | 68 kg | Details → |
| 32″ | 800 | 941 mm (37.05″) | 44.5 mm (1.75″) | 864 mm (34.02″) | 900.1 mm (35.44″) | 48 × Ø22.2 mm (0.87″) | 840 mm (33.07″) | 106 mm (4.17″) | 77.1 kg | Details → |
| 34″ | 850 | 1005 mm (39.57″) | 47.8 mm (1.88″) | 921 mm (36.26″) | 957.3 mm (37.69″) | 40 × Ø25.4 mm (1″) | 892 mm (35.12″) | 109 mm (4.29″) | 95.3 kg | Details → |
| 36″ | 900 | 1057 mm (41.61″) | 50.8 mm (2″) | 972 mm (38.27″) | 1009.6 mm (39.75″) | 44 × Ø25.4 mm (1″) | 945 mm (37.2″) | 116 mm (4.57″) | 109 kg | Details → |
| 38″ | 950 | 1124 mm (44.25″) | 52.6 mm (2.07″) | 1022 mm (40.24″) | 1069.8 mm (42.12″) | 40 × Ø28.6 mm (1.13″) | 997 mm (39.25″) | 122 mm (4.8″) | 132 kg | Details → |
| 40″ | 1000 | 1175 mm (46.26″) | 54 mm (2.13″) | 1080 mm (42.52″) | 1120.6 mm (44.12″) | 44 × Ø28.6 mm (1.13″) | 1049 mm (41.3″) | 127 mm (5″) | 141 kg | Details → |
| 42″ | 1050 | 1226 mm (48.27″) | 57.2 mm (2.25″) | 1130 mm (44.49″) | 1171.4 mm (46.12″) | 48 × Ø28.6 mm (1.13″) | 1102 mm (43.39″) | 132 mm (5.2″) | 156 kg | Details → |
| 44″ | 1100 | 1276 mm (50.24″) | 58.9 mm (2.32″) | 1181 mm (46.5″) | 1222.2 mm (48.12″) | 52 × Ø28.6 mm (1.13″) | 1153 mm (45.39″) | 135 mm (5.31″) | 141 kg | Details → |
| 46″ | 1150 | 1341 mm (52.8″) | 60.5 mm (2.38″) | 1235 mm (48.62″) | 1284.3 mm (50.56″) | 40 × Ø31.8 mm (1.25″) | 1205 mm (47.44″) | 143 mm (5.63″) | 197 kg | Details → |
| 48″ | 1200 | 1392 mm (54.8″) | 63.5 mm (2.5″) | 1289 mm (50.75″) | 1335.1 mm (52.56″) | 44 × Ø31.8 mm (1.25″) | 1257 mm (49.49″) | 148 mm (5.83″) | 218 kg | Details → |
| 50″ | 1250 | 1443 mm (56.81″) | 66.7 mm (2.63″) | 1340 mm (52.76″) | 1385.9 mm (54.56″) | 48 × Ø31.8 mm (1.25″) | 1308 mm (51.5″) | 152 mm (5.98″) | 236 kg | Details → |
| 52″ | 1300 | 1494 mm (58.82″) | 68.3 mm (2.69″) | 1391 mm (54.76″) | 1436.7 mm (56.56″) | 52 × Ø31.8 mm (1.25″) | 1360 mm (53.54″) | 156 mm (6.14″) | 236 kg | Details → |
| 54″ | 1350 | 1549 mm (60.98″) | 69.9 mm (2.75″) | 1441 mm (56.73″) | 1492.2 mm (58.75″) | 56 × Ø31.8 mm (1.25″) | 1413 mm (55.63″) | 161 mm (6.34″) | 281 kg | Details → |
| 56″ | 1400 | 1600 mm (62.99″) | 71.6 mm (2.82″) | 1492 mm (58.74″) | 1543 mm (60.75″) | 60 × Ø31.8 mm (1.25″) | 1465 mm (57.68″) | 165 mm (6.5″) | 295 kg | Details → |
| 58″ | 1450 | 1675 mm (65.94″) | 73.2 mm (2.88″) | 1543 mm (60.75″) | 1611.3 mm (63.44″) | 48 × Ø34.9 mm (1.37″) | 1516 mm (59.69″) | 173 mm (6.81″) | 354 kg | Details → |
| 60″ | 1500 | 1726 mm (67.95″) | 74.6 mm (2.94″) | 1600 mm (62.99″) | 1662.1 mm (65.44″) | 52 × Ø34.9 mm (1.37″) | 1570 mm (61.81″) | 178 mm (7.01″) | 386 kg | Details → |
JIS B2220
JIS B2220:2012 · Japan, Korea, South-East Asia, marine and shipbuilding
weld neck flange · 10K
| Size | DN | OD | Thickness | RF Ø | Bolt circle | Bolts | Hub Ø | Length | |
|---|---|---|---|---|---|---|---|---|---|
| 10A | 10 | 90 mm | 12 mm | 46 mm | 65 mm | 4 × Ø15 mm | 28 mm | 29 mm | Details → |
| 15A | 15 | 95 mm | 12 mm | 51 mm | 70 mm | 4 × Ø15 mm | 33 mm | 31 mm | Details → |
| 20A | 20 | 100 mm | 14 mm | 56 mm | 75 mm | 4 × Ø15 mm | 38 mm | 32 mm | Details → |
| 25A | 25 | 125 mm | 14 mm | 67 mm | 90 mm | 4 × Ø19 mm | 47 mm | 36 mm | Details → |
| 32A | 32 | 135 mm | 16 mm | 76 mm | 100 mm | 4 × Ø19 mm | 56 mm | 38 mm | Details → |
| 40A | 40 | 140 mm | 16 mm | 81 mm | 105 mm | 4 × Ø19 mm | 62 mm | 38 mm | Details → |
| 50A | 50 | 155 mm | 16 mm | 96 mm | 120 mm | 4 × Ø19 mm | 75 mm | 40 mm | Details → |
| 65A | 65 | 175 mm | 18 mm | 116 mm | 140 mm | 4 × Ø19 mm | 92 mm | 44 mm | Details → |
| 80A | 80 | 185 mm | 18 mm | 126 mm | 150 mm | 8 × Ø19 mm | 105 mm | 45 mm | Details → |
| 90A | 90 | 195 mm | 18 mm | 136 mm | 160 mm | 8 × Ø19 mm | 117 mm | 45 mm | Details → |
| 100A | 100 | 210 mm | 18 mm | 151 mm | 175 mm | 8 × Ø19 mm | 130 mm | 45 mm | Details → |
| 125A | 125 | 250 mm | 20 mm | 182 mm | 210 mm | 8 × Ø23 mm | 156 mm | 47 mm | Details → |
| 150A | 150 | 280 mm | 22 mm | 212 mm | 240 mm | 8 × Ø23 mm | 184 mm | 53 mm | Details → |
| 175A | 175 | 305 mm | 22 mm | 237 mm | 265 mm | 12 × Ø23 mm | 210 mm | 55 mm | Details → |
| 200A | 200 | 330 mm | 22 mm | 262 mm | 290 mm | 12 × Ø23 mm | 238 mm | 58 mm | Details → |
| 225A | 225 | 350 mm | 22 mm | 282 mm | 310 mm | 12 × Ø23 mm | 261 mm | 58 mm | Details → |
| 250A | 250 | 400 mm | 24 mm | 324 mm | 355 mm | 12 × Ø25 mm | 292 mm | 65 mm | Details → |
| 300A | 300 | 445 mm | 24 mm | 368 mm | 400 mm | 16 × Ø25 mm | 345 mm | 68 mm | Details → |
| 350A | 350 | 490 mm | 26 mm | 413 mm | 445 mm | 16 × Ø25 mm | 388 mm | 79 mm | Details → |
| 400A | 400 | 560 mm | 28 mm | 475 mm | 510 mm | 16 × Ø27 mm | 442 mm | 85 mm | Details → |
| 450A | 450 | 620 mm | 30 mm | 530 mm | 565 mm | 20 × Ø27 mm | 495 mm | 90 mm | Details → |
| 500A | 500 | 675 mm | 30 mm | 585 mm | 620 mm | 20 × Ø27 mm | 546 mm | 99 mm | Details → |
| 550A | 550 | 745 mm | 32 mm | 640 mm | 680 mm | 20 × Ø33 mm | 597 mm | 111 mm | Details → |
| 600A | 600 | 795 mm | 32 mm | 690 mm | 730 mm | 24 × Ø33 mm | 648 mm | 112 mm | Details → |
EN 1092-1
EN 1092-1:2018 · Europe, UK, Middle East, Africa, CIS projects
weld neck flange · PN16
| Size | DN | OD | Thickness | RF Ø | Bolt circle | Bolts | Hub Ø | Length | Weight | |
|---|---|---|---|---|---|---|---|---|---|---|
| DN10 | 10 | 90 mm | 16 mm | 40 mm | 60 mm | 4 × Ø14 mm | 28 mm | 35 mm | 0.7 kg | Details → |
| DN15 | 15 | 95 mm | 16 mm | 45 mm | 65 mm | 4 × Ø14 mm | 32 mm | 38 mm | 0.8 kg | Details → |
| DN20 | 20 | 105 mm | 18 mm | 58 mm | 75 mm | 4 × Ø14 mm | 40 mm | 40 mm | 1.1 kg | Details → |
| DN25 | 25 | 115 mm | 18 mm | 68 mm | 85 mm | 4 × Ø14 mm | 46 mm | 40 mm | 1.3 kg | Details → |
| DN32 | 32 | 140 mm | 18 mm | 78 mm | 100 mm | 4 × Ø18 mm | 56 mm | 42 mm | 1.9 kg | Details → |
| DN40 | 40 | 150 mm | 18 mm | 88 mm | 110 mm | 4 × Ø18 mm | 64 mm | 45 mm | 2.1 kg | Details → |
| DN50 | 50 | 165 mm | 18 mm | 102 mm | 125 mm | 4 × Ø18 mm | 74 mm | 45 mm | 2.5 kg | Details → |
| DN65 | 65 | 185 mm | 18 mm | 122 mm | 145 mm | 8 × Ø18 mm | 92 mm | 45 mm | 3 kg | Details → |
| DN80 | 80 | 200 mm | 20 mm | 138 mm | 160 mm | 8 × Ø18 mm | 105 mm | 50 mm | 3.9 kg | Details → |
| DN100 | 100 | 220 mm | 20 mm | 158 mm | 180 mm | 8 × Ø18 mm | 131 mm | 52 mm | 4.6 kg | Details → |
| DN125 | 125 | 250 mm | 22 mm | 188 mm | 210 mm | 8 × Ø18 mm | 156 mm | 55 mm | 6.3 kg | Details → |
| DN150 | 150 | 285 mm | 22 mm | 212 mm | 240 mm | 8 × Ø22 mm | 184 mm | 55 mm | 7.8 kg | Details → |
| DN200 | 200 | 340 mm | 24 mm | 268 mm | 295 mm | 12 × Ø22 mm | 235 mm | 62 mm | 11.5 kg | Details → |
| DN250 | 250 | 405 mm | 26 mm | 320 mm | 355 mm | 12 × Ø26 mm | 292 mm | 70 mm | 16.7 kg | Details → |
| DN300 | 300 | 460 mm | 28 mm | 378 mm | 410 mm | 12 × Ø26 mm | 344 mm | 78 mm | 22.1 kg | Details → |
| DN350 | 350 | 520 mm | 30 mm | 438 mm | 470 mm | 16 × Ø26 mm | 390 mm | 82 mm | 32.8 kg | Details → |
| DN400 | 400 | 580 mm | 32 mm | 490 mm | 525 mm | 16 × Ø30 mm | 445 mm | 85 mm | 41.1 kg | Details → |
| DN450 | 450 | 640 mm | 34 mm | 550 mm | 585 mm | 20 × Ø30 mm | — | — | — | Details → |
| DN500 | 500 | 715 mm | 36 mm | 610 mm | 650 mm | 20 × Ø33 mm | 548 mm | 84 mm | 66.2 kg | Details → |
| DN600 | 600 | 840 mm | 40 mm | 725 mm | 770 mm | 20 × Ø36 mm | 670 mm | 88 mm | 104 kg | Details → |
Full rating sets are published on the standard pages: B16.5 · B16.47 A · B16.47 B · JIS B2220 · EN 1092-1 . Tables are compiled from published ASME B16.5-2025, ASME B16.47-2025, Series A, ASME B16.47-2025, Series B, JIS B2220:2012, EN 1092-1:2018 data — verify against the edition named in your purchase specification before quoting a critical part.
Key features
Butt-weld geometry that passes RT
Hub bore, bevel angle and root face are machined to B16.5 so the joint can be radiographed or ultrasonically tested without rework. Pipe schedule matched on request.
Traceability by heat number
Heat number, grade and size are stamped on the rim. MTC 3.1, PMI report and dimensional record are filed against the same heat.
High-temperature service
A105 covers Group 1.1 carbon steel up to 425 °C; F11, F22 and F91 are stocked for refinery and power piping where creep strength matters.
Corrosion-resistant options
304/304L, 316/316L, 321, 347, duplex 2205 and super duplex 2507 are machined from forged rings, not plate, to keep through-thickness properties.
Typical applications
- Oil and gas transmission and gathering lines
- Refinery process piping and hydroprocessing units
- Steam and condensate systems in power plants
- Petrochemical and chemical reactors
- Offshore topsides and subsea manifolds
- Pipelines subject to pigging and in-line inspection
Quality control & documentation
- Chemical and mechanical tests per heat, reported on EN 10204 3.1 MTC
- 100% visual and dimensional inspection against B16.5 tables
- PMI on stainless and alloy heats to confirm grade
- UT or RT on request for critical service; MPI/PT on welds and faces
- Hydrostatic test per customer specification, with test pressure recorded
Material certificates to EN 10204 3.1 are issued with every shipment; third-party inspection (SGS, BV, TÜV) can be arranged on request.
Frequently asked questions
What is the difference between a weld neck and a slip-on flange?
A weld neck flange is butt-welded to the pipe through a tapered hub, so it handles higher pressure, temperature and cyclic load and can be fully radiographed. A slip-on flange slides over the pipe and is fillet-welded on both sides — cheaper and easier to align, but limited to lower-duty service.
Which material should I specify for a 300-class weld neck flange?
For non-corrosive service at ambient to moderate temperature, ASTM A105 is the standard choice. For low-temperature service down to −46 °C use A350 LF2; for corrosive or hygienic service use 304/316L; for refinery high-temperature hydrogen service consider F11, F22 or F91.
Can you supply flanges with a machined bore to match my pipe schedule?
Yes. Send the pipe specification (NPS, schedule, material) and we will machine the bore and bevel to match, so the internal diameter is flush with the pipe and the weld can be radiographed.
What is the typical lead time?
Standard sizes in A105 from stock ship in 7–15 days. Made-to-order sizes, alloy grades and RTJ faces typically take 20–30 days depending on quantity and testing requirements.
Request a quotation
Send your weld neck flange specification
Include the standard, size, pressure class, material, face type and quantity. Drawings are welcome — we will confirm feasibility, lead time and price within one business day.
- ★ Reply within 24 hours on business days
- ★ MTC 3.1 and dimensional report with every order
- ★ FOB, CIF and DDP terms available
Send an Inquiry
Send drawings, dimensions or a standard reference. Our sales engineers reply within 24 hours on business days.