Flanges
What are Flanges?
Flanges are mechanical components used to connect pipes, valves, pumps, and other equipment within piping systems. They provide easy access for cleaning, inspection, modification, or maintenance without dismantling the system entirely. Typically joined using bolts and gaskets, flanges ensure a secure, pressure-tight, and leak-proof seal.
Asiad Steel Industries is a leading manufacturer, supplier, and exporter of high-quality flanges in various pressure classes, sizes, and materials for diverse industrial applications.
Key Features
Strong & Reliable Connection
Durable
Construction
Easy Installation
& Removal
Wide
Compatibility
Corrosion
Resistant
Specifications
| Specification Category | Parameter / Feature | Details / Options |
|---|---|---|
| Size Range | Nominal Pipe Size (NPS) | ½” to 48” (DN15 – DN1200) |
| Custom Sizes | Available on request for special projects | |
| Pressure Ratings | ANSI / ASME Class | Class 150, 300, 400, 600, 900, 1500, 2500 |
| PN Ratings | PN6, PN10, PN16, PN25, PN40, PN64 | |
| Flange Face Types | Standard Faces | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ) |
| Specialty Faces | Tongue & Groove, Male-Female, Spiral Wound | |
| Connection Types | Welding & Joining | Welded (Butt Weld, Socket Weld), Slip-On |
| Mechanical Connections | Threaded, Lap Joint, Blind | |
| Material Options | Stainless Steel | SS 304, SS 304L, SS 316, SS 316L, SS 321 |
| Carbon Steel | CS A105, CS A350 LF2 | |
| Alloy / Superalloy | Alloy Steel, Inconel 625, Inconel 825 | |
| Duplex & Super Duplex | Duplex 2205, Super Duplex 2507 | |
| Other Materials | Monel, Titanium, Nickel Alloys | |
| Standards & Certifications | ASME / ANSI | ASME B16.5, ASME B16.47 |
| European Standards | DIN EN 1092-1, BS 4504 | |
| Testing & Quality | ISO 9001, PED 2014/68/EU, NACE MR0175 | |
| Design Features | Flange Thickness | As per ASME/ANSI, Customized options are available |
| Hub Length & Bore | Standard & Customized | |
| Bolt Holes & Bolt Circle Diameter | Precision drilled as per class | |
| Raised Face Height | 1.6 mm standard; other heights optional | |
| Coating & Surface Finish | Anti-Corrosion Coating | Rust preventive, Black oxide, Hot-dip galvanized |
| Optional Coatings | Epoxy, PTFE, Polyurethane | |
| Surface Finish | Machined, Polished, Passivated | |
| Testing & Inspection | Pressure Testing | Hydrostatic, Pneumatic |
| Nondestructive Testing (NDT) | RT, UT, PT, MT | |
| Dimensional Inspection | Full inspection per ASME / EN standards | |
| Applications | Industries | Oil & Gas, Petrochemical, Water Treatment, Power, Shipbuilding, Chemical |
| Fluid Type | Water, Oil, Gas, Steam, Corrosive Liquids | |
| Tolerance & Compliance | Dimensional Tolerance | ±1% standard; ±0.5% available for critical projects |
| Pressure & Rating Tolerance | As per ANSI/ASME Class standards | |
| Material Traceability | Full traceability with Mill Test Certificates (MTC) |
Dimensions of forged flanges ANSI 16.5 - ASA 150 class
| Size | Size | O | A | D | Holes | C | E | Y (WN) | Y (SW/Thd) | Y (LJ) | Bore (SW/Thd) | Bore (LJ) | R | F | X |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inch | mm | Flange Outer Dia (OD) | Bolt Circle | Bolt Hole Dia | No. of Holes | Thk | Hub Dia | Length Through Hub | Length Through Hub | Length Through Hub | Bore Dia | Bore Dia | R/F Dia | Socket Depth | Pipe OD |
| 1/2″ | 15 | 95.2 | 66.7 | 15.9 | 4 | 14.3 | 38.1 | 52.4 | 22.2 | 22.2 | 22.3 | 22.9 | 34.9 | 9.5 | 21.33 |
| 3/4″ | 20 | 117.5 | 82.5 | 19.0 | 4 | 15.9 | 47.6 | 57.1 | 25.4 | 25.4 | 27.7 | 28.2 | 42.9 | 11.1 | 26.67 |
| 1″ | 25 | 123.8 | 88.9 | 19.0 | 4 | 17.5 | 54.0 | 61.9 | 27.0 | 27.0 | 34.5 | 35.0 | 50.8 | 12.7 | 33.40 |
| 1 1/4″ | 32 | 133.3 | 98.4 | 19.0 | 4 | 20.6 | 63.5 | 66.7 | 28.6 | 28.4 | 43.2 | 43.6 | 63.5 | 14.2 | 42.16 |
| 1 1/2″ | 40 | 155.6 | 114.3 | 22.2 | 4 | 22.2 | 69.8 | 69.8 | 31.7 | 31.7 | 49.5 | 50.0 | 73.0 | 15.8 | 48.26 |
| 2″ | 50 | 165.1 | 127.0 | 19.0 | 8 | 25.4 | 84.1 | 73.0 | 36.5 | 36.5 | 62.0 | 62.4 | 92.1 | 17.4 | 60.31 |
| 2 1/2″ | 65 | 190.5 | 149.2 | 22.2 | 8 | 28.6 | 100.0 | 79.4 | 41.3 | 41.1 | 74.7 | 75.4 | 104.8 | 19.0 | 73.02 |
| 3″ | 80 | 209.5 | 168.3 | 22.2 | 8 | 31.8 | 117.5 | 82.5 | 46.0 | 45.9 | 90.7 | 91.4 | 127.0 | — | 88.90 |
| 3 1/2″ | 90 | 228.6 | 184.2 | 22.2 | 8 | 34.9 | 133.3 | 85.7 | 49.3 | 49.3 | 103.4 | 104.1 | 139.7 | — | 101.60 |
| 4″ | 100 | 273.0 | 215.9 | 25.4 | 8 | 38.1 | 152.4 | 101.6 | 54.0 | 53.8 | 116.1 | 116.8 | 157.2 | — | 114.30 |
| 5″ | 125 | 330.2 | 266.7 | 28.6 | 8 | 44.4 | 188.9 | 114.3 | 60.3 | 60.4 | 143.8 | 144.5 | 185.7 | — | 141.30 |
| 6″ | 150 | 355.6 | 292.1 | 28.6 | 12 | 47.6 | 222.2 | 117.5 | 66.7 | 66.5 | 170.7 | 171.4 | 215.9 | — | 168.27 |
| 8″ | 200 | 419.1 | 349.2 | 31.7 | 12 | 55.6 | 273.0 | 133.3 | 76.2 | 76.2 | 221.5 | 222.2 | 269.9 | — | 219.07 |
| 10″ | 250 | 508.0 | 431.8 | 34.9 | 16 | 63.5 | 342.9 | 152.4 | 85.7 | 111.2 | 276.3 | 277.3 | 323.8 | — | 273.05 |
| 12″ | 300 | 558.8 | 488.9 | 34.9 | 20 | 66.7 | 400.0 | 155.6 | 92.1 | 117.3 | 327.1 | 328.1 | 381.0 | — | 323.85 |
| 14″ | 350 | 603.2 | 527.0 | 38.1 | 20 | 69.9 | 431.8 | 165.1 | 93.7 | 127.0 | 359.1 | 360.1 | 412.7 | — | 355.60 |
| 16″ | 400 | 685.8 | 603.2 | 41.3 | 20 | 76.2 | 495.3 | 177.8 | 106.4 | 139.7 | 410.5 | 411.2 | 469.9 | — | 406.40 |
| 18″ | 450 | 742.9 | 654.0 | 44.4 | 20 | 82.6 | 546.1 | 184.1 | 117.5 | 152.4 | 461.8 | 462.2 | 533.4 | — | 457.20 |
| 20″ | 500 | 812.8 | 723.9 | 44.4 | 24 | 88.9 | 609.6 | 190.5 | 127.0 | 165.1 | 513.1 | 514.3 | 584.2 | — | 508.00 |
| 24″ | 600 | 939.8 | 838.2 | 50.8 | 24 | 101.6 | 717.5 | 203.2 | 139.7 | 184.1 | 615.9 | 615.9 | 692.1 | — | 609.60 |
Dimensions of forged flanges ANSI 16.5 - ASA 300 class
| Size | Size | O | A | D | Holes | C | E | Y (WN) | Y (SW/Thd) | Y (LJ) | Bore (SW/Thd) | Bore (LJ) | R | F | X |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inch | mm | Flange Outer Dia (OD) | Bolt Circle | Bolt Hole Dia | No. of Holes | Thk | Hub Dia | Length Through Hub | Length Through Hub | Length Through Hub | Bore Dia | Bore Dia | R/F Dia | Socket Depth | Pipe OD |
| 1/2″ | 15 | 95.2 | 66.7 | 15.9 | 4 | 14.3 | 38.1 | 52.4 | 22.2 | 22.2 | 22.3 | 22.9 | 34.9 | 9.5 | 21.33 |
| 3/4″ | 20 | 117.5 | 82.5 | 19.0 | 4 | 15.9 | 47.6 | 57.1 | 25.4 | 25.4 | 27.7 | 28.2 | 42.9 | 11.1 | 26.67 |
| 1″ | 25 | 123.8 | 88.9 | 19.0 | 4 | 17.5 | 54.0 | 61.9 | 27.0 | 27.0 | 34.5 | 35.0 | 50.8 | 12.7 | 33.40 |
| 1 1/4″ | 32 | 133.3 | 98.4 | 19.0 | 4 | 20.6 | 63.5 | 66.7 | 28.6 | 28.4 | 43.2 | 43.6 | 63.5 | 14.2 | 42.16 |
| 1 1/2″ | 40 | 155.6 | 114.3 | 22.2 | 4 | 22.2 | 69.8 | 69.8 | 31.7 | 31.7 | 49.5 | 50.0 | 73.0 | 15.8 | 48.26 |
| 2″ | 50 | 165.1 | 127.0 | 19.0 | 8 | 25.4 | 84.1 | 73.0 | 36.5 | 36.5 | 62.0 | 62.4 | 92.1 | 17.4 | 60.31 |
| 2 1/2″ | 65 | 190.5 | 149.2 | 22.2 | 8 | 28.6 | 100.0 | 79.4 | 41.3 | 41.1 | 74.7 | 75.4 | 104.8 | 19.0 | 73.02 |
| 3″ | 80 | 209.5 | 168.3 | 22.2 | 8 | 31.8 | 117.5 | 82.5 | 46.0 | 45.9 | 90.7 | 91.4 | 127.0 | — | 88.90 |
| 3 1/2″ | 90 | 228.6 | 184.2 | 22.2 | 8 | 34.9 | 133.3 | 85.7 | 49.3 | 49.3 | 103.4 | 104.1 | 139.7 | — | 101.60 |
| 4″ | 100 | 273.0 | 215.9 | 25.4 | 8 | 38.1 | 152.4 | 101.6 | 54.0 | 53.8 | 116.1 | 116.8 | 157.2 | — | 114.30 |
| 5″ | 125 | 330.2 | 266.7 | 28.6 | 8 | 44.4 | 188.9 | 114.3 | 60.3 | 60.4 | 143.8 | 144.5 | 185.7 | — | 141.30 |
| 6″ | 150 | 355.6 | 292.1 | 28.6 | 12 | 47.6 | 222.2 | 117.5 | 66.7 | 66.5 | 170.7 | 171.4 | 215.9 | — | 168.27 |
| 8″ | 200 | 419.1 | 349.2 | 31.7 | 12 | 55.6 | 273.0 | 133.3 | 76.2 | 76.2 | 221.5 | 222.2 | 269.9 | — | 219.07 |
| 10″ | 250 | 508.0 | 431.8 | 34.9 | 16 | 63.5 | 342.9 | 152.4 | 85.7 | 111.2 | 276.3 | 277.3 | 323.8 | — | 273.05 |
| 12″ | 300 | 558.8 | 488.9 | 34.9 | 20 | 66.7 | 400.0 | 155.6 | 92.1 | 117.3 | 327.1 | 328.1 | 381.0 | — | 323.85 |
| 14″ | 350 | 603.2 | 527.0 | 38.1 | 20 | 69.9 | 431.8 | 165.1 | 93.7 | 127.0 | 359.1 | 360.1 | 412.7 | — | 355.60 |
| 16″ | 400 | 685.8 | 603.2 | 41.3 | 20 | 76.2 | 495.3 | 177.8 | 106.4 | 139.7 | 410.5 | 411.2 | 469.9 | — | 406.40 |
| 18″ | 450 | 742.9 | 654.0 | 44.4 | 20 | 82.6 | 546.1 | 184.1 | 117.5 | 152.4 | 461.8 | 462.2 | 533.4 | — | 457.20 |
| 20″ | 500 | 812.8 | 723.9 | 44.4 | 24 | 88.9 | 609.6 | 190.5 | 127.0 | 165.1 | 513.1 | 514.3 | 584.2 | — | 508.00 |
| 24″ | 600 | 939.8 | 838.2 | 50.8 | 24 | 101.6 | 717.5 | 203.2 | 139.7 | 184.1 | 615.9 | 615.9 | 692.1 | — | 609.60 |
Dimensions of forged flanges ANSI 16.5 - ASA 600 class
| Size | Size | O | A | D | Holes | C | E | Y (WN) | Y (SW/Thd) | Y (LJ) | Bore (SW/Thd) | Bore (LJ) | R | F | X |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inch | mm | Flange Outer Dia (OD) | Bolt Circle | Bolt Hole Dia | No. of Holes | Thk | Hub Dia | Length Through Hub | Length Through Hub | Length Through Hub | Bore Dia | Bore Dia | R/F Dia | Socket Depth | Pipe OD |
| 1/2″ | 15 | 95.2 | 66.7 | 15.9 | 4 | 14.3 | 38.1 | 52.4 | 22.2 | 22.3 | 22.3 | 22.8 | 34.9 | 9.5 | 21.33 |
| 3/4″ | 20 | 117.5 | 82.5 | 19.0 | 4 | 15.9 | 47.6 | 57.1 | 25.4 | 25.4 | 27.7 | 28.1 | 42.9 | 11.1 | 26.67 |
| 1″ | 25 | 123.8 | 88.9 | 19.0 | 4 | 17.5 | 54.0 | 61.9 | 27.0 | 26.9 | 34.5 | 35.0 | 50.8 | 12.7 | 33.40 |
| 1 1/4″ | 32 | 133.3 | 98.4 | 19.0 | 4 | 20.6 | 63.5 | 66.7 | 28.6 | 28.4 | 43.2 | 43.6 | 63.5 | 14.2 | 42.16 |
| 1 1/2″ | 40 | 155.6 | 114.3 | 22.2 | 4 | 22.2 | 69.8 | 69.8 | 31.7 | 31.7 | 49.5 | 50.0 | 73.0 | 15.8 | 48.26 |
| 2″ | 50 | 165.1 | 127.0 | 19.0 | 8 | 25.4 | 84.1 | 73.0 | 36.5 | 36.5 | 62.0 | 62.4 | 92.1 | 17.4 | 60.31 |
| 2 1/2″ | 65 | 190.5 | 149.2 | 22.2 | 8 | 28.6 | 100.0 | 79.4 | 41.3 | 41.1 | 74.7 | 75.4 | 104.8 | 19.0 | 73.02 |
| 3″ | 80 | 209.5 | 168.3 | 22.2 | 8 | 31.8 | 117.5 | 82.5 | 46.0 | 45.9 | 90.7 | 91.4 | 127.0 | — | 88.90 |
| 3 1/2″ | 90 | 228.6 | 184.2 | 22.2 | 8 | 34.9 | 133.3 | 85.7 | 49.3 | 49.3 | 103.4 | 104.1 | 139.7 | — | 101.60 |
| 4″ | 100 | 273.0 | 215.9 | 25.4 | 8 | 38.1 | 152.4 | 101.6 | 54.0 | 53.8 | 116.1 | 116.8 | 157.2 | — | 114.30 |
| 5″ | 125 | 330.2 | 266.7 | 28.6 | 8 | 44.4 | 188.9 | 114.3 | 60.3 | 60.4 | 143.8 | 144.5 | 185.7 | — | 141.30 |
| 6″ | 150 | 355.6 | 292.1 | 28.6 | 12 | 47.6 | 222.2 | 117.5 | 66.7 | 66.5 | 170.7 | 171.4 | 215.9 | — | 168.27 |
| 8″ | 200 | 419.1 | 349.2 | 31.7 | 12 | 55.6 | 273.0 | 133.3 | 76.2 | 76.2 | 221.5 | 222.2 | 269.9 | — | 219.07 |
| 10″ | 250 | 508.0 | 431.8 | 34.9 | 16 | 63.5 | 342.9 | 152.4 | 85.7 | 111.2 | 276.3 | 277.3 | 323.8 | — | 273.05 |
| 12″ | 300 | 558.8 | 488.9 | 34.9 | 20 | 66.7 | 400.0 | 155.6 | 92.1 | 117.3 | 327.1 | 328.1 | 381.0 | — | 323.85 |
| 14″ | 350 | 603.2 | 527.0 | 38.1 | 20 | 69.9 | 431.8 | 165.1 | 93.7 | 127.0 | 359.1 | 360.1 | 412.7 | — | 355.60 |
| 16″ | 400 | 685.8 | 603.2 | 41.3 | 20 | 76.2 | 495.3 | 177.8 | 106.4 | 139.7 | 410.5 | 411.2 | 469.9 | — | 406.40 |
| 18″ | 450 | 742.9 | 654.0 | 44.4 | 20 | 82.6 | 546.1 | 184.1 | 117.5 | 152.4 | 461.8 | 462.2 | 533.4 | — | 457.20 |
| 20″ | 500 | 812.8 | 723.9 | 44.4 | 24 | 88.9 | 609.6 | 190.5 | 127.0 | 165.1 | 513.1 | 514.3 | 584.2 | — | 508.00 |
| 24″ | 600 | 939.8 | 838.2 | 50.8 | 24 | 101.6 | 717.5 | 203.2 | 139.7 | 184.1 | 615.9 | 615.9 | 692.1 | — | 609.60 |
Dimensions of forged flanges ANSI 16.5 - ASA 900 class
| Size | Size | O | A | D | Holes | C | E | Y (WN) | Y (SW/Thd) | Y (LJ) | Bore (SW/Thd) | Bore (LJ) | R | F | X |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Inch | mm | Flange Outer Dia (OD) | Bolt Circle | Bolt Hole Dia | No. of Holes | Thk | Hub Dia | Length Through Hub | Length Through Hub | Length Through Hub | Bore Dia | Bore Dia | R/F Dia | Socket Depth | Pipe OD |
| 1/2″ | 15 | 120.6 | 82.5 | 22.2 | 4 | 22.4 | 38.1 | 60.3 | 31.7 | 31.7 | 22.3 | 22.8 | 35.0 | 9.5 | 21.33 |
| 3/4″ | 20 | 130.0 | 88.9 | 22.2 | 4 | 25.4 | 44.4 | 69.8 | 35.0 | 35.0 | 27.7 | 28.2 | 42.9 | 11.1 | 26.67 |
| 1″ | 25 | 149.3 | 101.6 | 25.4 | 4 | 28.4 | 52.3 | 73.0 | 41.1 | 41.1 | 34.5 | 35.0 | 50.8 | 12.7 | 33.40 |
| 1 1/4″ | 32 | 158.7 | 111.1 | 25.4 | 4 | 28.4 | 63.5 | 73.0 | 41.1 | 41.1 | 43.1 | 43.6 | 63.5 | 14.3 | 42.16 |
| 1 1/2″ | 40 | 177.8 | 123.8 | 28.6 | 4 | 31.8 | 69.8 | 82.5 | 44.4 | 44.4 | 49.5 | 50.0 | 73.0 | 15.9 | 48.26 |
| 2″ | 50 | 215.9 | 165.1 | 25.4 | 8 | 38.1 | 104.8 | 101.6 | 57.1 | 57.1 | 62.0 | 62.4 | 92.1 | 17.4 | 60.31 |
| 2 1/2″ | 65 | 244.3 | 190.5 | 28.6 | 8 | 41.1 | 123.9 | 104.6 | 63.5 | 63.5 | 74.6 | 75.4 | 104.6 | 19.0 | 73.02 |
| 3″ | 80 | 241.3 | 190.5 | 25.4 | 8 | 38.1 | 127.0 | 101.6 | 53.8 | 53.8 | 90.6 | 91.4 | 127.0 | — | 88.90 |
| 4″ | 100 | 292.1 | 234.9 | 31.7 | 8 | 44.5 | 158.7 | 114.3 | 69.8 | 69.8 | 116.0 | 116.8 | 157.2 | — | 114.30 |
| 5″ | 125 | 349.2 | 279.4 | 35.0 | 8 | 50.8 | 190.5 | 127.0 | 79.3 | 79.3 | 143.7 | 144.5 | 185.7 | — | 141.30 |
| 6″ | 150 | 381.0 | 317.5 | 31.7 | 12 | 55.6 | 234.9 | 139.7 | 85.8 | 85.8 | 170.6 | 171.4 | 215.9 | — | 168.27 |
| 8″ | 200 | 469.9 | 393.7 | 38.1 | 12 | 63.5 | 298.4 | 162.0 | 101.6 | 114.3 | 221.4 | 222.2 | 269.7 | — | 219.07 |
| 10″ | 250 | 546.1 | 469.9 | 38.1 | 16 | 69.8 | 368.3 | 184.1 | 107.9 | 127.0 | 276.3 | 277.3 | 323.8 | — | 273.05 |
| 12″ | 300 | 609.6 | 533.4 | 38.1 | 20 | 79.2 | 419.1 | 200.1 | 117.3 | 142.7 | 327.1 | 328.1 | 381.0 | — | 323.85 |
| 14″ | 350 | 641.3 | 558.8 | 41.1 | 20 | 85.9 | 450.8 | 212.7 | 130.0 | 155.4 | 359.2 | 360.2 | 412.8 | — | 355.60 |
| 16″ | 400 | 704.8 | 615.9 | 44.4 | 20 | 88.9 | 508.0 | 215.9 | 133.4 | 165.1 | 410.5 | 411.2 | 469.9 | — | 406.40 |
| 18″ | 450 | 787.4 | 685.8 | 50.8 | 20 | 101.6 | 565.1 | 228.6 | 152.4 | 190.5 | 461.8 | 462.3 | 533.4 | — | 457.20 |
| 20″ | 500 | 857.2 | 749.3 | 53.8 | 20 | 107.9 | 622.3 | 247.7 | 158.8 | 209.6 | 513.1 | 514.3 | 584.2 | — | 508.00 |
| 24″ | 600 | 1041.4 | 901.7 | 66.6 | 20 | 139.7 | 749.3 | 292.1 | 203.2 | 266.7 | 615.9 | 615.9 | 692.2 | — | 609.60 |
Applications of Flanges
Construction &
Infrastructure
Power Generation &
Energy Sector
Manufacturing &
Fabrication
Medical & Laboratory
Equipment
Electrical &
Electronics Assembly
Oil, Gas & Petrochemical
Installations
Do you have questions?
What type of flange is best for high-pressure applications?
Are stainless steel flanges compatible with standard piping systems?
Are stainless steel flanges suitable for corrosive media?
Can I mix flange classes in a piping system?
