Flange drilling by standard and nominal bore — outside diameter, pitch circle, bolt count, hole size and bolt size — plus which of our flanged products we stock at that bore.
Find a bore
Pick a nominal bore to see every loaded standard side by side. The differences between them are the point: a valve drilled to one table will not bolt to another. Flange outside diameter, pitch circle diameter and bolt hole are in millimetres throughout.
ASME B16.5 Class 150
Raised face. The commonest steel flange on process and steam lines, and what "Class-150" means on a catalogue page.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 88.9 | 60.5 | 4 | 15.7 | 1/2" |
| 20 mm | 98.6 | 69.9 | 4 | 15.7 | 1/2" |
| 25 mm | 107.9 | 79.2 | 4 | 15.7 | 1/2" |
| 32 mm | 117.3 | 88.9 | 4 | 15.7 | 1/2" |
| 40 mm | 127.0 | 98.6 | 4 | 15.7 | 1/2" |
| 50 mm | 152.4 | 120.7 | 4 | 19.1 | 5/8" |
| 65 mm | 177.8 | 139.7 | 4 | 19.1 | 5/8" |
| 80 mm | 190.5 | 152.4 | 4 | 19.1 | 5/8" |
| 100 mm | 228.6 | 190.5 | 8 | 19.1 | 5/8" |
| 125 mm | 254.0 | 215.9 | 8 | 22.4 | 3/4" |
| 150 mm | 279.4 | 241.3 | 8 | 22.4 | 3/4" |
| 200 mm | 342.9 | 298.5 | 8 | 22.4 | 3/4" |
| 250 mm | 406.4 | 362.0 | 12 | 25.4 | 7/8" |
| 300 mm | 482.6 | 431.8 | 12 | 25.4 | 7/8" |
ASME B16.5 Class 300
Raised face. Same bores as Class 150 but a larger, more heavily bolted flange — the two never interchange.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.2 | 66.7 | 4 | 15.7 | 1/2" |
| 20 mm | 117.3 | 82.6 | 4 | 19.1 | 5/8" |
| 25 mm | 124.0 | 88.9 | 4 | 19.1 | 5/8" |
| 32 mm | 133.4 | 98.6 | 4 | 19.1 | 5/8" |
| 40 mm | 155.4 | 114.3 | 4 | 22.4 | 3/4" |
| 50 mm | 165.1 | 127.0 | 8 | 19.1 | 5/8" |
| 65 mm | 190.5 | 149.4 | 8 | 22.4 | 3/4" |
| 80 mm | 209.6 | 168.1 | 8 | 22.4 | 3/4" |
| 100 mm | 254.0 | 200.2 | 8 | 22.4 | 3/4" |
| 125 mm | 279.4 | 235.0 | 8 | 22.4 | 3/4" |
| 150 mm | 317.5 | 269.9 | 12 | 22.4 | 3/4" |
| 200 mm | 381.0 | 330.2 | 12 | 25.4 | 7/8" |
| 250 mm | 444.5 | 387.4 | 16 | 28.4 | 1" |
| 300 mm | 520.7 | 450.8 | 16 | 31.8 | 1 1/8" |
EN 1092-1 PN 16 (DIN 2533)
The European table this catalogue calls DIN 2533. PN 10 and PN 16 share drilling from DN 15 to DN 150, then diverge — which is exactly where the mistake gets made.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.0 | 65.0 | 4 | 14.0 | M12 |
| 20 mm | 105.0 | 75.0 | 4 | 14.0 | M12 |
| 25 mm | 115.0 | 85.0 | 4 | 14.0 | M12 |
| 32 mm | 140.0 | 100.0 | 4 | 18.0 | M16 |
| 40 mm | 150.0 | 110.0 | 4 | 18.0 | M16 |
| 50 mm | 165.0 | 125.0 | 4 | 18.0 | M16 |
| 65 mm | 185.0 | 145.0 | 8 | 18.0 | M16 |
| 80 mm | 200.0 | 160.0 | 8 | 18.0 | M16 |
| 100 mm | 220.0 | 180.0 | 8 | 18.0 | M16 |
| 125 mm | 250.0 | 210.0 | 8 | 18.0 | M16 |
| 150 mm | 285.0 | 240.0 | 8 | 22.0 | M20 |
| 200 mm | 340.0 | 295.0 | 12 | 22.0 | M20 |
| 250 mm | 405.0 | 355.0 | 12 | 26.0 | M24 |
| 300 mm | 460.0 | 410.0 | 12 | 26.0 | M24 |
EN 1092-1 PN 10 (DIN 2532)
Identical drilling to PN 16 up to DN 150. From DN 200 the flange is smaller and more lightly bolted, so a PN 16 valve will not sit on PN 10 pipework at those sizes.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.0 | 65.0 | 4 | 14.0 | M12 |
| 20 mm | 105.0 | 75.0 | 4 | 14.0 | M12 |
| 25 mm | 115.0 | 85.0 | 4 | 14.0 | M12 |
| 32 mm | 140.0 | 100.0 | 4 | 18.0 | M16 |
| 40 mm | 150.0 | 110.0 | 4 | 18.0 | M16 |
| 50 mm | 165.0 | 125.0 | 4 | 18.0 | M16 |
| 65 mm | 185.0 | 145.0 | 8 | 18.0 | M16 |
| 80 mm | 200.0 | 160.0 | 8 | 18.0 | M16 |
| 100 mm | 220.0 | 180.0 | 8 | 18.0 | M16 |
| 125 mm | 250.0 | 210.0 | 8 | 18.0 | M16 |
| 150 mm | 285.0 | 240.0 | 8 | 22.0 | M20 |
| 200 mm | 340.0 | 295.0 | 8 | 22.0 | M20 |
| 250 mm | 395.0 | 350.0 | 12 | 22.0 | M20 |
| 300 mm | 445.0 | 400.0 | 12 | 22.0 | M20 |
BS 10 Table D
The lightest of BS 10's pressure series — roughly comparable duty to PN 10 / Class 125, in the older imperial-derived British pattern this catalogue's stock is largely drilled to.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.3 | 66.7 | 4 | 12.7 | 1/2" |
| 20 mm | 101.6 | 73.0 | 4 | 12.7 | 1/2" |
| 25 mm | 114.3 | 82.6 | 4 | 12.7 | 1/2" |
| 32 mm | 120.7 | 87.3 | 4 | 12.7 | 1/2" |
| 40 mm | 133.4 | 98.4 | 4 | 12.7 | 1/2" |
| 50 mm | 152.4 | 114.3 | 4 | 15.9 | 5/8" |
| 65 mm | 165.1 | 127.0 | 4 | 15.9 | 5/8" |
| 80 mm | 184.2 | 146.1 | 4 | 15.9 | 5/8" |
| 100 mm | 215.9 | 177.8 | 4 | 15.9 | 5/8" |
| 125 mm | 254.0 | 209.6 | 8 | 15.9 | 5/8" |
| 150 mm | 279.4 | 228.6 | 8 | 15.9 | 5/8" |
| 200 mm | 336.6 | 292.1 | 8 | 15.9 | 5/8" |
| 250 mm | 406.4 | 355.6 | 8 | 19.1 | 3/4" |
| 300 mm | 457.2 | 406.4 | 12 | 19.1 | 3/4" |
BS 10 Table E
One step up from Table D — same bolt pattern at most sizes, thicker flange faces for the higher duty.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.3 | 66.3 | 4 | 12.7 | 1/2" |
| 20 mm | 101.6 | 73.0 | 4 | 12.7 | 1/2" |
| 25 mm | 114.3 | 82.6 | 4 | 12.7 | 1/2" |
| 32 mm | 120.7 | 87.3 | 4 | 12.7 | 1/2" |
| 40 mm | 133.4 | 98.4 | 4 | 12.7 | 1/2" |
| 50 mm | 152.4 | 114.3 | 4 | 15.9 | 5/8" |
| 65 mm | 165.1 | 127.0 | 4 | 15.9 | 5/8" |
| 80 mm | 184.2 | 146.1 | 4 | 15.9 | 5/8" |
| 100 mm | 215.9 | 177.8 | 8 | 15.9 | 5/8" |
| 125 mm | 254.0 | 209.6 | 8 | 15.9 | 5/8" |
| 150 mm | 279.4 | 228.6 | 8 | 19.1 | 3/4" |
| 200 mm | 336.6 | 292.1 | 8 | 19.1 | 3/4" |
| 250 mm | 406.4 | 355.6 | 12 | 19.1 | 3/4" |
| 300 mm | 457.2 | 406.4 | 12 | 22.2 | 7/8" |
BS 10 Table F
Heavier again than Table E — the drilling most often quoted for BS 10 duty above the lightest ranges.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.3 | 66.7 | 4 | 12.7 | 1/2" |
| 20 mm | 101.6 | 73.0 | 4 | 12.7 | 1/2" |
| 25 mm | 120.7 | 87.3 | 4 | 15.9 | 5/8" |
| 32 mm | 133.4 | 98.4 | 4 | 15.9 | 5/8" |
| 40 mm | 139.7 | 104.8 | 4 | 15.9 | 5/8" |
| 50 mm | 165.1 | 127.0 | 4 | 15.9 | 5/8" |
| 65 mm | 184.2 | 146.1 | 8 | 15.9 | 5/8" |
| 80 mm | 203.2 | 165.1 | 8 | 15.9 | 5/8" |
| 100 mm | 228.6 | 190.5 | 8 | 15.9 | 5/8" |
| 125 mm | 279.4 | 235.0 | 8 | 19.1 | 3/4" |
| 150 mm | 304.8 | 260.4 | 12 | 19.1 | 3/4" |
| 200 mm | 368.3 | 323.9 | 12 | 19.1 | 3/4" |
| 250 mm | 431.8 | 381.0 | 12 | 22.2 | 7/8" |
| 300 mm | 489.0 | 438.2 | 16 | 22.2 | 7/8" |
BS 10 Table H
The heaviest of the four BS 10 tables carried here — roughly 150-250 psi duty. Same bolt circle as Table F size-for-size, with a thicker flange face for the higher rating.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 114.3 | 82.6 | 4 | 15.9 | 5/8" |
| 20 mm | 114.3 | 82.6 | 4 | 15.9 | 5/8" |
| 25 mm | 120.7 | 87.3 | 4 | 15.9 | 5/8" |
| 32 mm | 133.4 | 98.4 | 4 | 15.9 | 5/8" |
| 40 mm | 139.7 | 104.8 | 4 | 15.9 | 5/8" |
| 50 mm | 165.1 | 127.0 | 4 | 15.9 | 5/8" |
| 65 mm | 184.2 | 146.1 | 8 | 15.9 | 5/8" |
| 80 mm | 203.2 | 165.1 | 8 | 15.9 | 5/8" |
| 100 mm | 228.6 | 190.5 | 8 | 15.9 | 5/8" |
| 125 mm | 279.4 | 235.0 | 8 | 19.1 | 3/4" |
| 150 mm | 304.8 | 260.4 | 12 | 19.1 | 3/4" |
| 200 mm | 368.3 | 323.9 | 12 | 19.1 | 3/4" |
| 250 mm | 431.8 | 381.0 | 12 | 22.2 | 7/8" |
| 300 mm | 489.0 | 438.2 | 16 | 22.2 | 7/8" |
IS 6392 Table 17
The Indian standard's own drilling, closest in duty to PN 16 but not identical to it — check this table specifically rather than assuming the EN 1092-1 PN 16 numbers above apply.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.0 | 65.0 | 4 | 14.0 | M12 |
| 20 mm | 105.0 | 75.0 | 4 | 14.0 | M12 |
| 25 mm | 115.0 | 85.0 | 4 | 14.0 | M12 |
| 32 mm | 140.0 | 100.0 | 4 | 18.0 | M16 |
| 40 mm | 150.0 | 110.0 | 4 | 18.0 | M16 |
| 50 mm | 165.0 | 125.0 | 4 | 18.0 | M16 |
| 65 mm | 185.0 | 145.0 | 4 | 18.0 | M16 |
| 80 mm | 200.0 | 160.0 | 8 | 18.0 | M16 |
| 100 mm | 220.0 | 180.0 | 8 | 18.0 | M16 |
| 125 mm | 250.0 | 210.0 | 8 | 18.0 | M16 |
| 150 mm | 285.0 | 240.0 | 8 | 22.0 | M20 |
| 200 mm | 340.0 | 295.0 | 12 | 22.0 | M20 |
| 250 mm | 405.0 | 355.0 | 12 | 26.0 | M24 |
| 300 mm | 460.0 | 410.0 | 12 | 26.0 | M24 |
DIN 2545 (PN 40)
The heaviest class carried here. Same family as the EN 1092-1 tables above but a materially larger, more heavily bolted flange at every bore — never assume a PN 16 or PN 25 valve will sit on PN 40 pipework.
| Bore | Flange OD | PCD | Bolts | Hole | Bolt |
|---|---|---|---|---|---|
| 15 mm | 95.0 | 65.0 | 4 | 14.0 | M12 |
| 20 mm | 105.0 | 75.0 | 4 | 14.0 | M12 |
| 25 mm | 115.0 | 85.0 | 4 | 14.0 | M12 |
| 32 mm | 140.0 | 100.0 | 4 | 18.0 | M16 |
| 40 mm | 150.0 | 110.0 | 4 | 18.0 | M16 |
| 50 mm | 165.0 | 125.0 | 4 | 18.0 | M16 |
| 65 mm | 185.0 | 145.0 | 8 | 18.0 | M16 |
| 80 mm | 200.0 | 160.0 | 8 | 18.0 | M16 |
| 100 mm | 235.0 | 190.0 | 8 | 22.0 | M20 |
| 125 mm | 270.0 | 220.0 | 8 | 26.0 | M24 |
| 150 mm | 300.0 | 250.0 | 8 | 26.0 | M24 |
| 200 mm | 375.0 | 320.0 | 12 | 30.0 | M27 |
| 250 mm | 450.0 | 385.0 | 12 | 30.0 | M27 |
| 300 mm | 515.0 | 450.0 | 16 | 33.0 | M30 |
Common questions
Are the flange dimensions on this page verified against the official standards?
No. Every table here is marked verified => false on the page. Most were sourced from trade-reference sites and cross-checked against a second independent source where possible — real evidence, better than a guess, but still not the standard document itself. Confirm against the actual standard before ordering.
Why do BS 10, ASME B16.5 and EN 1092-1 give different drilling for what looks like the same duty?
They are separate standards families with separate bolt circles, hole counts and hole diameters — a flange rated for a similar pressure in two different standards will usually not bolt up to each other. Match the standard actually specified, not just the nominal pressure class.
Which flange standard is most of your stock drilled to?
BS 10 is the family this catalogue uses most, which is exactly why it was the last one added here and is treated with the most caution — see the tables above for what is and is not covered yet.
What does "not yet loaded" mean under a standard listed on a product page?
It means that standard is named on products in our catalogue but its dimension table is not in this tool yet — omitted rather than estimated. Ask us to confirm the drilling directly for anything in that list.