flange standards table

Flange Standards & Dimensions

Flanges are essential components used to connect valves into pipework, facilitating easier removal and maintenance. There are various common flange standards, each with distinct features. Flanges within the same standard can either be flat (typically cast iron or ductile iron) or raised face (commonly cast steel and stainless steel). Below is a reference table detailing critical flange dimensions to aid in identifying the standard you have:

Hazardous areas
15mm (1/2")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 95 67 4 M12 14
AS 2129 Table C 95 67 4 M12 14
Table D 95 67 4 M12 14
Table E 95 67 4 M12 14
Table F 95 67 4 M12 14
Table H 114 83 4 M16 17
Table J 114 83 4 M16 17
ANSI B16.5 ANSI 150 89 60 4 13 16
ANSI 300 95 67 4 13 16
ANSI 600 95 67 4 13 16
ANSI 900 121 83 4 19 22
ANSI 1500 121 83 4 19 22
ISO 7005 (DIN) PN6 80 55 4 M10 11
PN10 95 65 4 M12 14
PN16 95 65 4 M12 14
PN20 90 60.5 4 M14 16
PN25 95 65 4 M12 14
PN40 95 65 4 M12 14
20mm (3/4")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 100 73 4 M12 14
AS 2129 Table C 100 73 4 M12 14
Table D 100 73 4 M12 14
Table E 100 73 4 M12 14
Table F 100 73 4 M12 14
Table H 115 83 4 M12 18
Table J 115 83 4 M12 18
ANSI B16.5 ANSI 150 98 70 4 M13 16
ANSI 300 117 83 4 M16 19
ANSI 600 117 83 4 M16 19
ANSI 900 130 89 4 19 22
ANSI 1500 130 89 4 19 22
ISO 7005 (DIN) PN6 90 65 4 M10 11
PN10 105 75 4 M12 14
PN16 105 75 4 M12 14
PN20 100 70 4 M14 16
PN25 105 75 4 M12 14
PN40 105 75 4 M12 14
25mm (1")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 115 83 4 M12 14
AS 2129 Table C 115 83 4 M12 14
Table D 115 83 4 M12 14
Table E 115 83 4 M12 14
Table F 120 87 4 M16 18
Table H 120 87 4 M16 18
Table J 120 87 4 M16 18
ANSI B16.5 ANSI 150 110 79 4 13 16
ANSI 300 125 89 4 16 19
ANSI 600 125 89 4 16 19
ANSI 900 102 4 22 25
ANSI 1500 102 4 22 25
ISO 7005 (DIN) PN6 100 78 4 M10 11
PN10 155 85 4 M12 14
PN16 155 85 4 M12 14
PN20 110 79.5 4 M14 16
PN25 115 85 4 M12 14
PN40 115 85 4 M12 14
32mm (1 1/4")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 120 87 4 M12 14
AS 2129 Table C 120 87 4 M12 14
Table D 120 87 4 M12 14
Table E 120 87 4 M12 14
Table F 135 98 4 M16 18
Table H 135 98 4 M16 18
Table J 135 98 4 M16 18
ANSI B16.5 ANSI 150 117 89 4 13 16
ANSI 300 133 98 4 16 19
ANSI 600 133 98 4 16 19
ANSI 900 159 111 4 22 25
ANSI 1500 159 111 4 22 25
ISO 7005 (DIN) PN6 120 90 4 M12 14
PN10 140 100 4 M16 18
PN16 140 100 4 M16 18
PN20 120 89 4 M14 16
PN25 140 100 4 M16 18
PN40 140 100 4 M16 18
40mm (1 1/2")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 135 98 4 M12 14
AS 2129 Table C 135 98 4 M12 14
Table D 135 98 4 M12 14
Table E 135 98 4 M12 14
Table F 140 105 4 M16 18
Table H 140 105 4 M16 18
Table J 140 105 4 M16 18
ANSI B16.5 ANSI 150 127 98 4 13 16
ANSI 300 156 114 4 19 22
ANSI 600 156 114 4 19 22
ANSI 900 178 124 4 25 29
ANSI 1500 178 124 4 25 29
ISO 7005 (DIN) PN6 130 100 4 M12 14
PN10 150 110 4 M16 18
PN16 150 110 4 M16 18
PN20 130 98.5 4 M14 16
PN25 150 110 4 M16 18
PN40 150 110 4 M16 18
50mm (2")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 150 114 4 M16 18
PN16 150 114 4 M16 18
PN21 165 127 4 M16 18
PN35 165 127 4 M16 18
AS 2129 Table C 150 114 4 M16 18
Table D 150 114 4 M16 18
Table E 150 114 4 M16 18
Table F 165 127 4 M16 18
Table H 165 127 4 M16 18
Table J 165 127 4 M20 22
ANSI B16.5 ANSI 150 152 121 4 16 19
ANSI 300 165 127 8 16 19
ANSI 600 165 127 8 16 19
ANSI 900 216 165 8 22 25
ANSI 1500 216 165 8 22 25
ISO 7005 (DIN) PN6 140 110 4 M12 14
PN10 165 125 4 M16 18
PN16 165 125 4 M16 18
PN20 150* 120.5 4 M16 18
PN25 165 125 4 M16 18
PN40 165 125 4 M16 18
* When made from cast or ductile iron the OD is 155mm.
65mm (2 1/2")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 165 127 4 M16 18
PN16 165 127 4 M16 18
PN21 185 146 8 M16 18
PN35 185 146 8 M16 18
AS 2129 Table C 165 127 4 M16 18
Table D 165 127 4 M16 18
Table E 165 127 4 M16 18
Table F 185 146 8 M16 18
Table H 185 146 8 M16 18
Table J 185 146 8 M20 22
ANSI B16.5 ANSI 150 178 140 4 16 19
ANSI 300 191 149 8 19 22
ANSI 600 191 149 8 19 22
ANSI 900 244 191 8 22 25
ANSI 1500 244 191 8 25 29
ISO 7005 (DIN) PN6 160 130 4 M12 14
PN10 185 145 4 M16 18
PN16 185 145 4 M16 18
PN20 180 139.5 4 M16 18
PN25 185 145 8 M16 18
PN40 185 145 8 M16 18
80mm (3")
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 185 146 4 M16 18
PN16 185 146 4 M16 18
PN21 205 165 8 M16 18
PN35 205 165 8 M16 18
AS 2129 Table C 185 146 4 M16 18
Table D 185 146 4 M16 18
Table E 185 146 4 M16 18
Table F 205 165 8 M16 18
Table H 205 165 8 M16 18
Table J 205 165 8 M20 22
ANSI B16.5 ANSI 150 191 152 4 16 19
ANSI 300 210 168 8 19 22
ANSI 600 210 168 8 19 22
ANSI 900 241 192 8 22 25
ANSI 1500 267 203 8 29 32
ISO 7005 (DIN) PN6 190 150 4 M16 18
PN10 200 160 8 M16 18
PN16 200 160 8 M16 18
PN20 190 152.5 4 M16 18
PN25 200 160 8 M16 18
PN40 185 160 8 M16 18
100mm (4") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 215 178 4 M16 18
PN16 215 178 4 M16 18
PN21 230 191 8 M16 18
PN35 230 191 8 M16 18
AS 2129 Table C 215 178 4 M16 18
Table D 215 178 4 M16 18
Table E 215 178 8 M16 18
Table F 230 191 8 M16 18
Table H 230 191 8 M16 18
Table J 230 191 8 M20 22
ANSI B16.5 ANSI 150 229 191 8 16 19
ANSI 300 254 200 8 19 22
ANSI 600 273 216 8 22 25
ANSI 900 292 235 8 29 32
ANSI 1500 311 241 8 32 35
ISO 7005 (DIN) PN6 210 170 4 M16 18
PN10 220 180 8 M16 24
PN16 220 180 8 M16 18
PN20 230 190.5 8 M16 18
PN25 235 190 8 M20 22
PN40 235 190 8 M20 22
125mm (5") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 255 210 8 M16 18
PN16 255 210 8 M16 18
PN21 280 235 8 M20 22
PN35 280 235 8 M20 22
AS 2129 Table C 255 210 8 M16 18
Table D 255 210 8 M16 18
Table E 255 210 8 M16 18
Table F 280 235 8 M20 22
Table H 280 235 8 M20 22
Table J 280 235 8 M24 26
ANSI B16.5 ANSI 150 254 216 8 19 22
ANSI 300 279 235 8 19 22
ANSI 600 330 267 8 25 29
ANSI 900 349 279 8 32 35
ANSI 1500 375 292 8 38 41
ISO 7005 (DIN) PN6 240 200 8 M16 18
PN10 250 210 8 M16 18
PN16 250 210 8 M16 18
PN20 255 216 8 M20 22
PN25 270 220 8 M24 26
PN40 270 220 8 M24 26
150mm (6") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 280 235 8 M16 18
PN16 280 235 8 M16 18
PN21 305 260 12 M20 22
PN35 305 260 12 M20 22
AS 2129 Table C 280 235 8 M16 18
Table D 280 235 8 M16 18
Table E 280 235 8 M20 22
Table F 305 260 12 M20 22
Table H 305 260 12 M20 22
Table J 305 260 12 M24 26
ANSI B16.5 ANSI 150 279 241 8 19 22
ANSI 300 318 270 12 19 22
ANSI 600 356 292 12 25 29
ANSI 900 381 318 12 29 32
ANSI 1500 394 318 12 35 38
ISO 7005 (DIN) PN6 265 225 8 M16 18
PN10 285 240 8 M20 22
PN16 285 240 8 M20 22
PN20 280 241.5 8 M20 22
PN25 300 250 8 M24 26
PN40 300 250 8 M24 26
200mm (8") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 335 292 8 M16 18
PN16 335 292 8 M16 18
PN21 370 324 12 M20 22
PN35 370 324 12 M20 22
AS 2129 Table C 335 292 8 M16 18
Table D 335 292 8 M16 18
Table E 335 292 8 M20 22
Table F 370 324 12 M20 22
Table H 370 324 12 M20 22
Table J 370 324 12 M24 26
ANSI B16.5 ANSI 150 343 298 8 19 22
ANSI 300 381 330 12 19 22
ANSI 600 419 349 12 29 32
ANSI 900 470 394 12 35 38
ANSI 1500 483 394 12 41 44
ISO 7005 (DIN) PN6 320 280 8 M16 18
PN10 340 295 8 M20 22
PN16 340 295 12 M20 22
PN20 335 298.5 12 M20 22
PN25 360 310 12 M24 26
PN40 360 310 12 M24 26
250mm (10") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 405 356 8 M20 22
PN16 405 356 8 M20 22
PN21 430 381 12 M24 26
PN35 430 381 12 M24 26
AS 2129 Table C 405 356 8 M20 22
Table D 405 356 8 M20 22
Table E 405 356 12 M20 22
Table F 430 381 12 M24 26
Table H 430 381 12 M24 26
Table J 430 381 12 M27 30
ANSI B16.5 ANSI 150 406 362 12 22 25
ANSI 300 445 387 16 25 29
ANSI 600 508 432 16 32 35
ANSI 900 546 470 16 35 38
ANSI 1500 584 483 12 41 51
ISO 7005 (DIN) PN6 375 335 12 M16 18
PN10 395 350 12 M20 22
PN16 405 355 12 M24 26
PN20 405 362 12 M24 26
PN25 425 370 12 M27 30
PN40 450 385 12 M30 33
300mm (12") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 455 406 12 M20 22
PN16 455 406 12 M20 22
PN21 490 438 16 M24 26
PN35 490 438 16 M24 26
AS 2129 Table C 455 406 12 M20 22
Table D 455 406 12 M20 22
Table E 455 406 12 M24 26
Table F 490 438 16 M24 26
Table H 490 438 16 M24 26
Table J 490 438 16 M27 30
ANSI B16.5 ANSI 150 483 432 12 22 25
ANSI 300 521 451 16 29 32
ANSI 600 559 489 20 32 35
ANSI 900 610 533 20 35 38
ANSI 1500 673 571 16 51 54
ISO 7005 (DIN) PN6 440 395 12 M20 22
PN10 445 400 12 M20 22
PN16 460 410 12 M24 26
PN20 485 432 12 M24 26
PN25 485 430 16 M27 30
PN40 515 450 16 M30 33
350mm (14") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 525 470 12 M24 26
PN16 525 470 12 M24 26
PN21 550 495 16 M27 30
PN35 550 495 16 M27 30
AS 2129 Table C 525 470 12 M24 26
Table D 525 470 12 M24 26
Table E 525 470 12 M24 26
Table F 550 495 16 M27 30
Table H 550 495 16 M27 30
Table J 550 495 16 M30 32
ANSI B16.5 ANSI 150 533 476 12 25 29
ANSI 300 584 514 20 29 32
ANSI 600 603 527 20 38 41
ANSI 900 641 559 20 38 41
ANSI 1500 749 635 16 57 60
ISO 7005 (DIN) PN6 490 445 12 M20 22
PN10 505 460 16 M20 22
PN16 520 470 16 M24 26
PN20 535 476 12 M27 35
PN25 555 490 16 M30 33
PN40 580 510 16 M33 36
400mm (16") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 580 521 12 M24 26
PN16 580 521 12 M24 26
PN21 610 552 20 M27 30
PN35 610 552 20 M27 30
AS 2129 Table C 580 521 12 M24 26
Table D 580 521 12 M24 26
Table E 580 521 12 M24 26
Table F 610 552 20 M27 30
Table H 610 552 20 M27 30
Table J 610 552 20 M30 33
ANSI B16.5 ANSI 150 597 540 16 1" (M24) 29
ANSI 300 648 572 20 1-1/4" (M30) 35
ANSI 600 686 603 20 1-1/2" (M36) 41
ANSI 900 705 616 20 1-5/8" (M42) 44
ANSI 1500 826 705 16 2-1/2" (M64) 67
ISO 7005 (DIN) PN6 540 495 16 M20 22
PN10 565 515 16 M24 26
PN16 580 525 16 M27 30
PN20 600 540 16 M27 29.5
PN25 620 550 16 M33 36
PN40 660 585 16 M36 39
450mm (18") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 Flange 640 584 12 M24 26
PN16 Flange 640 584 12 M24 26
PN21 Flange 675 610 20 M30 33
PN35 Flange 675 610 20 M30 33
AS 2129 Table C Flange 640 584 12 M24 26
Table D Flange 640 584 12 M24 26
Table E Flange 640 584 16 M24 26
Table F Flange 675 610 20 M30 33
Table H Flange 675 610 20 M30 33
Table J Flange 675 610 20 M33 36
ANSI B16.5 ANSI 150 Flange 635 578 16 1-1/8" (M27) 32
ANSI 300 Flange 711 629 24 1-1/4" (M30) 35
ANSI 600 Flange 743 654 20 1-5/8" (M42) 44
ANSI 900 Flange 787 686 20 1-7/8" (M48) 51
ANSI 1500 Flange 914 775 16 2-3/4" (M72) 73
ISO 7005 (DIN) PN6 Flange 595 550 16 M20 22
PN10 Flange 615 565 20 M24 26
PN16 Flange 640 585 20 M27 30
PN20 Flange 635 578 16 M30 32.5
PN25 Flange - - - - -
PN40 Flange - - - - -
500mm (20") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 705 641 16 M24 26
PN16 705 641 16 M24 26
PN21 735 673 24 M30 33
PN35 735 673 24 M30 33
AS 2129 Table C 705 641 16 M24 26
Table D 705 641 16 M24 26
Table E 705 641 16 M24 26
Table F 735 673 24 M30 33
Table H 735 673 24 M30 33
Table J 735 673 24 M33 36
ANSI B16.5 ANSI 150 711 654 20 1-1/4" (M30) 35
ANSI 300 775 692 20 1-5/8" (M42) 44
ANSI 600 812 727 24 1-7/8" (M48) 51
ANSI 900 845 755 24 2-1/8" (M56) 58
ANSI 1500 984 832 20 3" (M76) 79
ISO 7005 (DIN) PN6 600 560 20 M20 22
PN10 620 570 20 M24 26
PN16 715 650 20 M27 30
PN20 730 660 20 M30 32.5
PN25 745 670 20 M33 36
PN40 810 730 24 M36 39
600mm (24") Flange Standards
Standard Class Diameter Bolt Circle Diameter Number of Bolts Bolt Size Diameter of Bolt Hole
AS 4087 PN14 Flanges 825 756 16 M27 30
PN16 Flanges 825 756 16 M27 30
PN21 Flanges 850 781 24 M33 36
PN35 Flanges 750 781 24 M33 36
AS 2129 Table C Flanges 825 756 16 M27 30
Table D Flanges 825 756 16 M27 30
Table E Flanges 825 756 16 M30 33
Table F Flanges 850 781 24 M33 36
Table H Flanges 850 781 24 M33 36
ANSI B16.5 ANSI 150 Flanges 813 749 20 1-1/4" (M30) 35
ANSI 300 Flanges 914 813 24 1-1/2" (M36) 41
ANSI 600 Flanges 940 838 24 1-7/8" (M48) 51
ANSI 900 Flanges 1041 902 20 2-1/2" (M64) 67
ANSI 1500 Flanges 1168 991 16 3-1/2" (M90) 92
ISO 7005 (DIN) PN6 Flanges 755 705 20 M24 26
PN10 Flanges 780 725 20 M27 30
PN16 Flanges 840 770 20 M33 36
PN20 Flanges 815 749.5 20 M33 36
PN25 Flanges - - - - -
PN40 Flanges - - - - -

DISCLAIMER – this service is provided without warranty or claim of fitness for any purpose. Triple i takes no responsibility for the accuracy of the figures provided and customers should use this service at their own risk.