ASME B16.5 blind flange: dimensions and weight by class
Disc without a central bore that closes the end of lines, nozzles and vessels. Also used as a hydrostatic test point and for future expansion.
StandardASME B16.5-2020
Classes150, 300, 400, 600, 900, 1,500, 2,500
Range in class 150NPS ½ to 24
Unitsmm, kg; hole and bolt in inches
Dimensions by pressure class
Choose the class and click a row: the drawing changes to the scale and dimensions of that diameter.
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" | 15 | 89 | 9.7 | 35.1 | 60.5 | 4 | ⅝" | ½" | 0.4 |
| ¾" | 20 | 99 | 11.2 | 42.9 | 69.8 | 4 | ⅝" | ½" | 0.6 |
| 1" | 25 | 108 | 12.7 | 50.8 | 79.2 | 4 | ⅝" | ½" | 0.9 |
| 1¼" | 32 | 117 | 14.2 | 63.5 | 88.9 | 4 | ⅝" | ½" | 1.1 |
| 1½" | 40 | 127 | 15.9 | 73 | 98.6 | 4 | ⅝" | ½" | 1.5 |
| 2" | 50 | 152 | 17.5 | 91.9 | 120.6 | 4 | ¾" | ⅝" | 2.4 |
| 2½" | 65 | 178 | 20.6 | 104.6 | 139.7 | 4 | ¾" | ⅝" | 3.9 |
| 3" | 80 | 190 | 22.4 | 127 | 152.4 | 4 | ¾" | ⅝" | 4.9 |
| 3½" | 90 | 216 | 22.4 | 139.7 | 177.8 | 8 | ¾" | ⅝" | 6.2 |
| 4" | 100 | 229 | 22.4 | 157.2 | 190.5 | 8 | ¾" | ⅝" | 7.1 |
| 5" | 125 | 254 | 22.4 | 185.7 | 215.9 | 8 | ⅞" | ¾" | 8.7 |
| 6" | 150 | 279 | 23.9 | 215.9 | 241.3 | 8 | ⅞" | ¾" | 11.3 |
| 8" | 200 | 343 | 26.9 | 269.7 | 298.4 | 8 | ⅞" | ¾" | 19.6 |
| 10" | 250 | 406 | 28.4 | 323.8 | 362.0 | 12 | 1" | ⅞" | 28.5 |
| 12" | 300 | 483 | 30.2 | 381 | 431.8 | 12 | 1" | ⅞" | 43.4 |
| 14" | 350 | 533 | 33.3 | 412.8 | 476.2 | 12 | 1⅛" | 1" | 58 |
| 16" | 400 | 597 | 35.1 | 469.9 | 539.8 | 16 | 1⅛" | 1" | 76.5 |
| 18" | 450 | 635 | 38.1 | 533.4 | 577.8 | 16 | 1¼" | 1⅛" | 93.7 |
| 20" | 500 | 698.5 | 41.1 | 584.2 | 635.0 | 20 | 1¼" | 1⅛" | 120 |
| 22" | 550 | 749 | 44.4 | 641.4 | 692.2 | 20 | 1⅜" | 1¼" | 151 |
| 24" | 600 | 813 | 46.0 | 692.2 | 749.3 | 20 | 1⅜" | 1¼" | 185.3 |
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" | 15 | 95 | 12.7 | 35.1 | 66.5 | 4 | ⅝" | ½" | 0.6 |
| ¾" | 20 | 117 | 14.2 | 42.9 | 82.6 | 4 | ¾" | ⅝" | 1.1 |
| 1" | 25 | 124 | 15.7 | 50.8 | 88.9 | 4 | ¾" | ⅝" | 1.4 |
| 1¼" | 32 | 133 | 17.5 | 63.5 | 98.6 | 4 | ¾" | ⅝" | 1.8 |
| 1½" | 40 | 155 | 19.0 | 73 | 114.3 | 4 | ⅞" | ¾" | 2.6 |
| 2" | 50 | 165 | 20.6 | 91.9 | 127.0 | 8 | ¾" | ⅝" | 3.2 |
| 2½" | 65 | 190 | 23.9 | 104.6 | 149.4 | 8 | ⅞" | ¾" | 4.8 |
| 3" | 80 | 210 | 26.9 | 127 | 168.1 | 8 | ⅞" | ¾" | 6.8 |
| 3½" | 90 | 229 | 28.4 | 139.7 | 184.2 | 8 | ⅞" | ¾" | 8.7 |
| 4" | 100 | 254 | 30.2 | 157.2 | 200.2 | 8 | ⅞" | ¾" | 11.5 |
| 5" | 125 | 279 | 33.3 | 185.7 | 235.0 | 8 | ⅞" | ¾" | 15.5 |
| 6" | 150 | 318 | 35.1 | 215.9 | 269.7 | 12 | ⅞" | ¾" | 21.1 |
| 8" | 200 | 381 | 39.6 | 269.7 | 330.2 | 12 | 1" | ⅞" | 34.3 |
| 10" | 250 | 444 | 46.0 | 323.8 | 387.4 | 16 | 1⅛" | 1" | 53.2 |
| 12" | 300 | 521 | 49.3 | 381 | 450.8 | 16 | 1¼" | 1⅛" | 79 |
| 14" | 350 | 584 | 52.3 | 412.8 | 514.4 | 20 | 1¼" | 1⅛" | 105.2 |
| 16" | 400 | 648 | 55.6 | 469.9 | 571.5 | 20 | 1⅜" | 1¼" | 137.8 |
| 18" | 450 | 711 | 58.7 | 533.4 | 628.6 | 24 | 1⅜" | 1¼" | 175.2 |
| 20" | 500 | 775 | 62.0 | 584.2 | 685.8 | 24 | 1⅜" | 1¼" | 221.8 |
| 22" | 550 | 838 | 65.0 | 641.4 | 743.0 | 24 | 1⅝" | 1½" | 269.1 |
| 24" | 600 | 914 | 68.3 | 692.2 | 812.8 | 24 | 1⅝" | 1½" | 339.3 |
Up to NPS 3½, class 400 uses the same dimensions as class 600 (rows marked "= 600").
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" = 600 | 15 | 95 | 14.2 | 35.1 | 66.5 | 4 | ⅝" | ½" | 0.8 |
| ¾" = 600 | 20 | 117 | 15.7 | 42.9 | 82.6 | 4 | ¾" | ⅝" | 1.3 |
| 1" = 600 | 25 | 124 | 17.5 | 50.8 | 88.9 | 4 | ¾" | ⅝" | 1.6 |
| 1¼" = 600 | 32 | 133 | 20.6 | 63.5 | 98.6 | 4 | ¾" | ⅝" | 2.2 |
| 1½" = 600 | 40 | 155 | 22.4 | 73 | 114.3 | 4 | ⅞" | ¾" | 3.3 |
| 2" = 600 | 50 | 165 | 25.4 | 91.9 | 127.0 | 8 | ¾" | ⅝" | 4.1 |
| 2½" = 600 | 65 | 190 | 28.4 | 104.6 | 149.4 | 8 | ⅞" | ¾" | 6.1 |
| 3" = 600 | 80 | 210 | 31.8 | 127 | 168.1 | 8 | ⅞" | ¾" | 8.5 |
| 3½" = 600 | 90 | 229 | 35.1 | 139.7 | 184.2 | 8 | 1" | ⅞" | 11 |
| 4" | 100 | 254 | 35.1 | 157.2 | 200.2 | 8 | 1" | ⅞" | 13.8 |
| 5" | 125 | 279 | 38.1 | 185.7 | 235.0 | 8 | 1" | ⅞" | 18.4 |
| 6" | 150 | 318 | 41.1 | 215.9 | 269.7 | 12 | 1" | ⅞" | 25.5 |
| 8" | 200 | 381 | 47.8 | 269.7 | 330.2 | 12 | 1⅛" | 1" | 42.8 |
| 10" | 250 | 444 | 53.8 | 323.8 | 387.4 | 16 | 1¼" | 1⅛" | 64.2 |
| 12" | 300 | 521 | 57.2 | 381 | 450.8 | 16 | 1⅜" | 1¼" | 94.6 |
| 14" | 350 | 584 | 60.5 | 412.8 | 514.4 | 20 | 1⅜" | 1¼" | 124.8 |
| 16" | 400 | 648 | 63.5 | 469.9 | 571.5 | 20 | 1½" | 1⅜" | 161.7 |
| 18" | 450 | 711 | 66.5 | 533.4 | 628.6 | 24 | 1½" | 1⅜" | 204.2 |
| 20" | 500 | 775 | 69.8 | 584.2 | 685.8 | 24 | 1⅝" | 1½" | 254.3 |
| 22" | 550 | 838 | 73.2 | 641.4 | 743.0 | 24 | 1¾" | 1⅝" | 311.8 |
| 24" | 600 | 914 | 76.2 | 692.2 | 812.8 | 24 | 1⅞" | 1¾" | 385.8 |
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" | 15 | 95 | 14.2 | 35.1 | 66.5 | 4 | ⅝" | ½" | 0.8 |
| ¾" | 20 | 117 | 15.7 | 42.9 | 82.6 | 4 | ¾" | ⅝" | 1.3 |
| 1" | 25 | 124 | 17.5 | 50.8 | 88.9 | 4 | ¾" | ⅝" | 1.6 |
| 1¼" | 32 | 133 | 20.6 | 63.5 | 98.6 | 4 | ¾" | ⅝" | 2.2 |
| 1½" | 40 | 155 | 22.4 | 73 | 114.3 | 4 | ⅞" | ¾" | 3.3 |
| 2" | 50 | 165 | 25.4 | 91.9 | 127.0 | 8 | ¾" | ⅝" | 4.1 |
| 2½" | 65 | 190 | 28.4 | 104.6 | 149.4 | 8 | ⅞" | ¾" | 6.1 |
| 3" | 80 | 210 | 31.8 | 127 | 168.1 | 8 | ⅞" | ¾" | 8.5 |
| 3½" | 90 | 229 | 35.1 | 139.7 | 184.2 | 8 | 1" | ⅞" | 11 |
| 4" | 100 | 273 | 38.1 | 157.2 | 215.9 | 8 | 1" | ⅞" | 17.3 |
| 5" | 125 | 330 | 44.4 | 185.7 | 266.7 | 8 | 1⅛" | 1" | 29.4 |
| 6" | 150 | 356 | 47.8 | 215.9 | 292.1 | 12 | 1⅛" | 1" | 36.3 |
| 8" | 200 | 419 | 55.6 | 269.7 | 349.2 | 12 | 1¼" | 1⅛" | 58.9 |
| 10" | 250 | 508 | 63.5 | 323.8 | 431.8 | 16 | 1⅜" | 1¼" | 97.5 |
| 12" | 300 | 559 | 66.5 | 381 | 489.0 | 20 | 1⅜" | 1¼" | 123.8 |
| 14" | 350 | 603 | 69.8 | 412.8 | 527.0 | 20 | 1½" | 1⅜" | 150.7 |
| 16" | 400 | 686 | 76.2 | 469.9 | 603.2 | 20 | 1⅝" | 1½" | 213.8 |
| 18" | 450 | 743 | 82.6 | 533.4 | 654.0 | 20 | 1¾" | 1⅝" | 272.2 |
| 20" | 500 | 813 | 88.9 | 584.2 | 723.9 | 24 | 1¾" | 1⅝" | 349.8 |
| 22" | 550 | 870 | 95.2 | 641.4 | 777.7 | 24 | 1⅞" | 1¾" | 428.5 |
| 24" | 600 | 940 | 101.6 | 692.2 | 838.2 | 24 | 2" | 1⅞" | 533.6 |
Up to NPS 2½, class 900 uses the same dimensions as class 1500 (rows marked "= 1500").
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" = 1500 | 15 | 121 | 22.4 | 35.1 | 82.6 | 4 | ⅞" | ¾" | 1.8 |
| ¾" = 1500 | 20 | 130 | 25.4 | 42.9 | 88.9 | 4 | ⅞" | ¾" | 2.4 |
| 1" = 1500 | 25 | 149 | 28.4 | 50.8 | 101.6 | 4 | 1" | ⅞" | 3.5 |
| 1¼" = 1500 | 32 | 159 | 28.4 | 63.5 | 111.1 | 4 | 1" | ⅞" | 4.1 |
| 1½" = 1500 | 40 | 178 | 31.8 | 73 | 124.0 | 4 | 1⅛" | 1" | 5.8 |
| 2" = 1500 | 50 | 216 | 38.1 | 91.9 | 165.1 | 8 | 1" | ⅞" | 10.1 |
| 2½" = 1500 | 65 | 244 | 41.1 | 104.6 | 190.5 | 8 | 1⅛" | 1" | 13.9 |
| 3" | 80 | 241 | 38.1 | 127 | 190.5 | 8 | 1" | ⅞" | 13.1 |
| 4" | 100 | 292 | 44.5 | 157.2 | 235.0 | 8 | 1¼" | 1⅛" | 22.2 |
| 5" | 125 | 349 | 50.8 | 185.7 | 279.4 | 8 | 1⅜" | 1¼" | 36.5 |
| 6" | 150 | 381 | 55.6 | 215.9 | 317.5 | 12 | 1¼" | 1⅛" | 47.5 |
| 8" | 200 | 470 | 63.5 | 269.7 | 393.7 | 12 | 1½" | 1⅜" | 82.5 |
| 10" | 250 | 546 | 69.8 | 323.8 | 469.9 | 16 | 1½" | 1⅜" | 122.4 |
| 12" | 300 | 610 | 79.2 | 381 | 533.4 | 20 | 1½" | 1⅜" | 173.2 |
| 14" | 350 | 641 | 85.9 | 412.8 | 558.8 | 20 | 1⅝" | 1½" | 206.3 |
| 16" | 400 | 705 | 88.9 | 469.9 | 616.0 | 20 | 1¾" | 1⅝" | 259.5 |
| 18" | 450 | 787 | 101.6 | 533.4 | 685.8 | 20 | 2" | 1⅞" | 366.9 |
| 20" | 500 | 857 | 108.0 | 584.2 | 749.3 | 20 | 2⅛" | 2" | 463.7 |
| 24" | 600 | 1041 | 139.7 | 692.2 | 901.7 | 20 | 2⅝" | 2½" | 875.7 |
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" | 15 | 121 | 22.4 | 35.1 | 82.6 | 4 | ⅞" | ¾" | 1.8 |
| ¾" | 20 | 130 | 25.4 | 42.9 | 88.9 | 4 | ⅞" | ¾" | 2.4 |
| 1" | 25 | 149 | 28.4 | 50.8 | 101.6 | 4 | 1" | ⅞" | 3.5 |
| 1¼" | 32 | 159 | 28.4 | 63.5 | 111.1 | 4 | 1" | ⅞" | 4.1 |
| 1½" | 40 | 178 | 31.8 | 73 | 124.0 | 4 | 1⅛" | 1" | 5.8 |
| 2" | 50 | 216 | 38.1 | 91.9 | 165.1 | 8 | 1" | ⅞" | 10.1 |
| 2½" | 65 | 244 | 41.1 | 104.6 | 190.5 | 8 | 1⅛" | 1" | 13.9 |
| 3" | 80 | 267 | 47.8 | 127 | 203.2 | 8 | 1¼" | 1⅛" | 19.3 |
| 4" | 100 | 311 | 53.8 | 157.2 | 241.3 | 8 | 1⅜" | 1¼" | 29.8 |
| 5" | 125 | 375 | 73.2 | 185.7 | 292.1 | 8 | 1⅝" | 1½" | 58.7 |
| 6" | 150 | 394 | 82.6 | 215.9 | 317.5 | 12 | 1½" | 1⅜" | 72 |
| 8" | 200 | 483 | 91.9 | 269.7 | 393.7 | 12 | 1¾" | 1⅝" | 121.6 |
| 10" | 250 | 584 | 108.0 | 323.8 | 482.6 | 12 | 2" | 1⅞" | 210.6 |
| 12" | 300 | 673 | 124.0 | 381 | 571.5 | 16 | 2⅛" | 2" | 316.4 |
| 14" | 350 | 749 | 133.4 | 412.8 | 635.0 | 16 | 2⅜" | 2¼" | 420.2 |
| 16" | 400 | 826 | 146.0 | 469.9 | 704.8 | 16 | 2⅝" | 2½" | 558.8 |
| 18" | 450 | 914 | 162.1 | 533.4 | 774.7 | 16 | 2⅞" | 2¾" | 760.9 |
| 20" | 500 | 984 | 177.8 | 584.2 | 831.8 | 16 | 3⅛" | 3" | 964.4 |
| 24" | 600 | 1168 | 203.2 | 692.2 | 990.6 | 16 | 3⅝" | 3½" | 1558.1 |
| NPS | DN | O | tf | R | W | No. of holes | Hole Ø | Bolt Ø | Weight* |
|---|---|---|---|---|---|---|---|---|---|
| ½" | 15 | 133 | 30.2 | 35.1 | 88.9 | 4 | ⅞" | ¾" | 3 |
| ¾" | 20 | 140 | 31.8 | 42.9 | 95.2 | 4 | ⅞" | ¾" | 3.5 |
| 1" | 25 | 159 | 35.1 | 50.8 | 108.0 | 4 | 1" | ⅞" | 5 |
| 1¼" | 32 | 184 | 38.1 | 63.5 | 130.0 | 4 | 1⅛" | 1" | 7.3 |
| 1½" | 40 | 203 | 44.4 | 73 | 146.0 | 4 | 1¼" | 1⅛" | 10.4 |
| 2" | 50 | 235 | 50.8 | 91.9 | 171.4 | 8 | 1⅛" | 1" | 15.6 |
| 2½" | 65 | 267 | 57.2 | 104.6 | 196.8 | 8 | 1¼" | 1⅛" | 22.7 |
| 3" | 80 | 305 | 66.5 | 127 | 228.6 | 8 | 1⅜" | 1¼" | 34.8 |
| 4" | 100 | 356 | 76.2 | 157.2 | 273.0 | 8 | 1⅝" | 1½" | 54.1 |
| 5" | 125 | 419 | 91.9 | 185.7 | 323.8 | 8 | 1⅞" | 1¾" | 90.6 |
| 6" | 150 | 483 | 108.0 | 215.9 | 368.3 | 8 | 2⅛" | 2" | 141.7 |
| 8" | 200 | 552 | 127.0 | 269.7 | 438.2 | 12 | 2⅛" | 2" | 214.1 |
| 10" | 250 | 673 | 165.1 | 323.8 | 539.8 | 12 | 2⅝" | 2½" | 410.9 |
| 12" | 300 | 762 | 184.2 | 381 | 619.3 | 12 | 2⅞" | 2¾" | 592.5 |
Section drawing, proportional to the table dimensions (mm).
O = outside diameter · tf = thickness without raised face · R = raised face diameter · W = bolt circle. * Weight estimated from geometry in carbon steel.
Frequently asked questions
What is the asme b16.5 blind flange: dimensions and weight by class used for?
Disc without a central bore that closes the end of lines, nozzles and vessels. Also used as a hydrostatic test point and for future expansion.
Do the dimensions include the raised face?
No. Since the 2017 edition, the thickness (tf) and length (Y) in ASME B16.5 are measured without the raised face. Add 1.6 mm for classes 150 and 300 and 6.4 mm from class 400 upward.
In which materials does Dustre supply it?
A105 and A350 LF2 carbon steel, F304L and F316L stainless, F51/F60 duplex, F53/F55 super duplex, F11, F22 and F91 Cr-Mo, nickel alloys and titanium, forged and machined with 3.1 certificate.
Blind in special alloysForged and machined at Dustre, in any class, with 3.1 certificate.
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