Flange dimensions: ASME B16.5 chart and finder, Class 150 to 2500
Every ASME B16.5 dimension for ½ to 24 inch flanges in all six pressure classes, drawn to scale for weld neck, slip-on, socket weld, threaded, lap joint and blind.
Flange finder
Choose size, class, type and facing. Values appear on the drawing and can be sent to us as an enquiry.
Flange dimension finder
Every ASME B16.5 dimension for weld neck, slip-on, socket weld, threaded, lap joint and blind flanges, Class 150 to 2500. The section redraws to scale as you change type, size and class.
Dimensions per ASME B16.5. The raised face is not included in thickness or hub length. Matching stud bolts come from Teshi Fasteners as a set.
What OD, PCD and bolts mean
- ODOutside diameter
- PCDPitch circle (bolt circle) diameter
- BoltsNumber of holes x stud diameter
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Send sizes, grades and quantities. Our estimation team usually replies within one working day.
ASME B16.5 tables by class
Full tables for every size and flange type, in mm and inch.
OD, bolt circle and bolting, Class 150 to 2500
| Size | Class 150 | Class 300 | Class 600 | Class 900 | Class 1500 | Class 2500 | |
|---|---|---|---|---|---|---|---|
| 1/2" (15 NB) | 88.9 / 60.5 4 × 1/2" | 95.2 / 66.5 4 × 1/2" | 95.2 / 66.5 4 × 1/2" | 120.6 / 82.5 4 × 3/4" | 120.6 / 82.5 4 × 3/4" | 133.3 / 88.9 4 × 3/4" | Quote |
| 3/4" (20 NB) | 98.6 / 69.8 4 × 1/2" | 117.3 / 82.5 4 × 5/8" | 117.3 / 82.5 4 × 5/8" | 130.0 / 88.9 4 × 3/4" | 130.0 / 88.9 4 × 3/4" | 139.7 / 95.2 4 × 3/4" | Quote |
| 1" (25 NB) | 107.9 / 79.2 4 × 1/2" | 124.0 / 88.9 4 × 5/8" | 124.0 / 88.9 4 × 5/8" | 149.4 / 101.6 4 × 7/8" | 149.4 / 101.6 4 × 7/8" | 158.8 / 107.9 4 × 7/8" | Quote |
| 1-1/4" (32 NB) | 117.3 / 88.9 4 × 1/2" | 133.3 / 98.6 4 × 5/8" | 133.3 / 98.6 4 × 5/8" | 158.8 / 111.3 4 × 7/8" | 158.8 / 111.3 4 × 7/8" | 184.1 / 130.3 4 × 1" | Quote |
| 1-1/2" (40 NB) | 127.0 / 98.6 4 × 1/2" | 155.4 / 114.3 4 × 3/4" | 155.4 / 114.3 4 × 3/4" | 177.8 / 124.0 4 × 1" | 177.8 / 124.0 4 × 1" | 203.2 / 146.0 4 × 1-1/8" | Quote |
| 2" (50 NB) | 152.4 / 120.6 4 × 5/8" | 165.1 / 127.0 8 × 5/8" | 165.1 / 127.0 8 × 5/8" | 215.9 / 165.1 8 × 7/8" | 215.9 / 165.1 8 × 7/8" | 234.9 / 171.4 8 × 1" | Quote |
| 2-1/2" (65 NB) | 177.8 / 139.7 4 × 5/8" | 190.5 / 149.4 8 × 3/4" | 190.5 / 149.4 8 × 3/4" | 244.3 / 190.5 8 × 1" | 244.3 / 190.5 8 × 1" | 266.7 / 196.8 8 × 1-1/8" | Quote |
| 3" (80 NB) | 190.5 / 152.4 4 × 5/8" | 209.5 / 168.1 8 × 3/4" | 209.5 / 168.1 8 × 3/4" | 241.3 / 190.5 8 × 7/8" | 266.7 / 203.2 8 × 1-1/8" | 304.8 / 228.6 8 × 1-1/4" | Quote |
| 3-1/2" (90 NB) | 215.9 / 177.8 8 × 5/8" | 228.6 / 184.1 8 × 3/4" | 228.6 / 184.1 8 × 7/8" | – | – | – | Quote |
| 4" (100 NB) | 228.6 / 190.5 8 × 5/8" | 254.0 / 200.2 8 × 3/4" | 273.1 / 215.9 8 × 7/8" | 292.1 / 234.9 8 × 1-1/8" | 311.1 / 241.3 8 × 1-1/4" | 355.6 / 273.1 8 × 1-1/2" | Quote |
| 5" (125 NB) | 254.0 / 215.9 8 × 3/4" | 279.4 / 234.9 8 × 3/4" | 330.2 / 266.7 8 × 1" | 349.2 / 279.4 8 × 1-1/4" | 374.6 / 292.1 8 × 1-1/2" | 419.1 / 323.8 8 × 1-3/4" | Quote |
| 6" (150 NB) | 279.4 / 241.3 8 × 3/4" | 317.5 / 269.7 12 × 3/4" | 355.6 / 292.1 12 × 1" | 381.0 / 317.5 12 × 1-1/8" | 393.7 / 317.5 12 × 1-3/8" | 482.6 / 368.3 8 × 2" | Quote |
| 8" (200 NB) | 342.9 / 298.4 8 × 3/4" | 381.0 / 330.2 12 × 7/8" | 419.1 / 349.2 12 × 1-1/8" | 469.9 / 393.7 12 × 1-3/8" | 482.6 / 393.7 12 × 1-5/8" | 552.4 / 438.1 12 × 2" | Quote |
| 10" (250 NB) | 406.4 / 361.9 12 × 7/8" | 444.5 / 387.3 16 × 1" | 508.0 / 431.8 16 × 1-1/4" | 546.1 / 469.9 16 × 1-3/8" | 584.2 / 482.6 12 × 1-7/8" | 673.1 / 539.8 12 × 2-1/2" | Quote |
| 12" (300 NB) | 482.6 / 431.8 12 × 7/8" | 520.7 / 450.8 16 × 1-1/8" | 558.8 / 488.9 20 × 1-1/4" | 609.6 / 533.4 20 × 1-3/8" | 673.1 / 571.5 16 × 2" | 762.0 / 619.3 12 × 2-3/4" | Quote |
| 14" (350 NB) | 533.4 / 476.2 12 × 1" | 584.2 / 514.4 20 × 1-1/8" | 603.2 / 527.0 20 × 1-3/8" | 641.3 / 558.8 20 × 1-1/2" | 749.3 / 635.0 16 × 2-1/4" | – | Quote |
| 16" (400 NB) | 596.9 / 539.8 16 × 1" | 647.7 / 571.5 20 × 1-1/4" | 685.8 / 603.2 20 × 1-1/2" | 704.8 / 615.9 20 × 1-5/8" | 825.5 / 704.8 16 × 2-1/2" | – | Quote |
| 18" (450 NB) | 635.0 / 577.9 16 × 1-1/8" | 711.2 / 628.6 24 × 1-1/4" | 742.9 / 654.0 20 × 1-5/8" | 787.4 / 685.8 20 × 1-7/8" | 914.4 / 774.7 16 × 2-3/4" | – | Quote |
| 20" (500 NB) | 698.5 / 635.0 20 × 1-1/8" | 774.7 / 685.8 24 × 1-1/4" | 812.8 / 723.9 24 × 1-5/8" | 857.2 / 749.3 20 × 2" | 984.2 / 831.8 16 × 3" | – | Quote |
| 24" (600 NB) | 812.8 / 749.3 20 × 1-1/4" | 914.4 / 812.8 24 × 1-1/2" | 939.8 / 838.2 24 × 1-7/8" | 1041.4 / 901.7 20 × 2-1/2" | 1168.4 / 990.6 16 × 3-1/2" | – | Quote |
Questions buyers ask
What is PCD on a flange?
PCD is the pitch circle diameter, the diameter of the circle through the centres of the bolt holes. It must match on both flanges of a joint.
Are Class 150 and PN16 flanges interchangeable?
Not in general. ASME B16.5 and EN 1092-1 flanges have different bolt circles and bolt sizes in most sizes. Tell us which standard your mating equipment uses.
Get a quotation from the manufacturer
Send your BOQ, drawing or tender reference. You deal directly with the manufacturer.
- Reply from our estimation team, usually within one working day
- Carbon steel to titanium on one order
- EN 10204 3.1 or 3.2 certificates, third-party inspection welcome
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