Engineering reference · ASME B16.47
ASME B16.47 Flange Dimension Finder, Series A and B
ASME B16.47 covers large-diameter steel flanges from NPS 26 to NPS 60, in two series. Pick the series, pressure class, pipe size and flange type to see the dimensions in millimetres and inches on a 3D section model drawn to scale.
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| NPSDN | OOutside diameter | tfFlange thickness, min. | RRaised face diameter | WBolt circle diameter | n×⌀Bolt holes | BoltsBolt size | XHub diameter at base | AHub diameter at weld end | YLength through hub |
|---|---|---|---|---|---|---|---|---|---|
| 26DN 650 | 870.0 | 66.8 | 749.3 | 806.5 | 24 × ⌀35.1 | 24 × 1-1/4 in | 676.1 | 660.4 | 119.1 |
| 28DN 700 | 927.1 | 69.9 | 800.1 | 863.6 | 28 × ⌀35.1 | 28 × 1-1/4 in | 726.9 | 711.2 | 124.0 |
| 30DN 750 | 984.3 | 73.2 | 857.3 | 914.4 | 28 × ⌀35.1 | 28 × 1-1/4 in | 781.1 | 762.0 | 135.1 |
| 32DN 800 | 1060.5 | 79.5 | 914.4 | 977.9 | 28 × ⌀41.1 | 28 × 1-1/2 in | 831.9 | 812.8 | 143.0 |
| 34DN 850 | 1111.3 | 81.0 | 965.2 | 1028.7 | 32 × ⌀41.1 | 32 × 1-1/2 in | 882.7 | 863.6 | 147.8 |
| 36DN 900 | 1168.4 | 88.9 | 1022.4 | 1085.9 | 32 × ⌀41.1 | 32 × 1-1/2 in | 933.5 | 914.4 | 155.7 |
| 38DN 950 | 1238.3 | 85.9 | 1073.2 | 1149.4 | 32 × ⌀41.1 | 32 × 1-1/2 in | 990.6 | 965.2 | 155.7 |
| 40DN 1000 | 1289.1 | 88.9 | 1124.0 | 1200.2 | 36 × ⌀41.1 | 36 × 1-1/2 in | 1041.4 | 1016.0 | 162.1 |
| 42DN 1050 | 1346.2 | 95.3 | 1193.8 | 1257.3 | 36 × ⌀41.1 | 36 × 1-1/2 in | 1092.2 | 1066.8 | 169.9 |
| 44DN 1100 | 1403.4 | 100.1 | 1244.6 | 1314.5 | 40 × ⌀41.1 | 40 × 1-1/2 in | 1143.0 | 1117.6 | 176.3 |
| 46DN 1150 | 1454.2 | 101.6 | 1295.4 | 1365.3 | 40 × ⌀41.1 | 40 × 1-1/2 in | 1196.8 | 1168.4 | 184.2 |
| 48DN 1200 | 1511.3 | 106.4 | 1358.9 | 1422.4 | 44 × ⌀41.1 | 44 × 1-1/2 in | 1247.6 | 1219.2 | 190.5 |
| 50DN 1250 | 1568.5 | 109.7 | 1409.7 | 1479.6 | 44 × ⌀47.8 | 44 × 1-3/4 in | 1301.8 | 1270.0 | 201.7 |
| 52DN 1300 | 1625.6 | 114.3 | 1460.5 | 1536.7 | 44 × ⌀47.8 | 44 × 1-3/4 in | 1352.6 | 1320.8 | 208.0 |
| 54DN 1350 | 1682.8 | 119.1 | 1511.3 | 1593.9 | 44 × ⌀47.8 | 44 × 1-3/4 in | 1403.4 | 1371.6 | 214.4 |
| 56DN 1400 | 1746.3 | 122.4 | 1574.8 | 1651.0 | 48 × ⌀47.8 | 48 × 1-3/4 in | 1457.5 | 1422.4 | 227.1 |
| 58DN 1450 | 1803.4 | 127.0 | 1625.6 | 1708.2 | 48 × ⌀47.8 | 48 × 1-3/4 in | 1508.3 | 1473.2 | 233.4 |
| 60DN 1500 | 1854.2 | 130.3 | 1676.4 | 1759.0 | 52 × ⌀47.8 | 52 × 1-3/4 in | 1559.1 | 1524.0 | 238.3 |
Select a row to show that size on the drawing. A dash (—) means the value is not shown because it is not confirmed by two sources; we do not fill it in. Bore is not tabulated: it follows the pipe wall you specify.
What ASME B16.47 covers
ASME B16.47 is the standard for large-diameter steel pipe flanges from NPS 26 to NPS 60, in Classes 75, 150, 300, 400, 600 and 900. It sets their dimensions, tolerances, materials, marking and testing. This page shows two flange types, weld neck and blind, with outside diameter, thickness, raised face, bolt circle, drilling and, for the weld neck, the hub dimensions. For NPS 24 and smaller, use our ASME B16.5 dimension finder.
Series A and Series B
Series A (the former MSS SP-44 flanges) and Series B (the former API 605 flanges) have their own dimension tables for outside diameter, thickness, bolt circle and drilling, so a flange made to one series is not assumed to mate with a flange of the other. Series A is tabulated for Classes 150 to 900 and Series B for Classes 75 to 900, and you choose the series by what the flange must mate with, as our guide to ASME B16.47 Series A vs Series B explains.
How the numbers are stated
- Raised face. Flange thickness (tf) and hub length (Y) exclude the raised face. The raised face is 0.06 in (1.5 mm) high on Class 75, 150 and 300, and 0.25 in (6.4 mm) high on Class 400, 600 and 900.
- Bolting. Bolt size is the bolt-hole diameter minus 1/8 in.
- Units. Inch values are the master figures. Millimetres are the inch values × 25.4, rounded to 0.1 mm.
- Bore. Bore is not tabulated in B16.47. It follows the pipe wall you specify, so we ask for the wall thickness or schedule with every weld neck flange RFQ. The bore drawn on the 3D model is illustrative.
- Missing values. Where a value is not confirmed by two independent sources, it is not shown and the table prints a dash. If you need one of those values, send us the line item and we review it against the drawing or table before we quote.
Sources. Values cross-checked between independent published dimension tables; where they disagreed the value is not shown. Check against the edition your specification calls for.
What we supply in these sizes
We supply flanges in ASME B16.47 sizes NPS 26 to 60. Our D51 mill rolls rings up to 1,500 mm OD and 240 mm thick; larger rings are forged by partner forges near our plant in Dingxiang. We review each line item (series, class, NPS, facing, bore and material) against the drawing or table before we quote it. The tables on this page show what the standard lists, not what we make: not every combination of series, class and size is available, so send us the line items you need and we confirm them. See also our weld neck flanges and blind flanges.
What to send with an RFQ for a B16.47 flange
- Series: A or B.
- Pressure class and NPS.
- Flange type: weld neck or blind.
- Facing, for example raised face or ring joint.
- Bore or pipe wall thickness, for a weld neck flange.
- Material grade and specification.
- Quantity.
- Certificate type and any testing you need.
- Destination port.
If the flange must match an existing one, or differs from the standard table, send the drawing too. Our RFQ checklist for forged flanges covers the rest of the request.
Reference only. This page is a buying aid, not the standard, and not a quotation. Machining, tolerances and acceptance go by the edition of ASME B16.47 your order calls for and your project drawing. Data checked 2026-10-14 · NPS 26 to 60 · Series A Class 150 to 900, Series B Class 75 to 900.