Lap Joint Flanges
What are Lap Joint Flanges?
Lap Joint Flanges are two-piece pipe connection components consisting of a flange and a stub end. The flange slides freely over the pipe and is positioned behind the stub end, which is welded to the pipe. This design allows for easy alignment and rotation of the flange, making it ideal for piping systems that require frequent disassembly or realignment.
Asiad Steel Industries is a leading manufacturer and exporter of high-quality Lap Joint Flanges in stainless steel, carbon steel, and special alloys for diverse industries worldwide.
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) |
| Pressure Ratings | ANSI / ASME Class Class 150, 300, 600, 900, 1500, 2500PN Ratings PN6, PN10, PN16, PN25, PN40, PN64 |
|
| Fitting Types | Lap Joint Flanges | Standard Lap Joint, Slip-On Lap Joint, Weld Neck Lap Joint |
| Material Options | Stainless Steel | SS 304, SS 304L, SS 316, SS 316L, SS 321 |
| Carbon Steel | ASTM A105, ASTM A350 LF2 | |
| Alloy / Superalloy | Alloy Steel (A182 F1, F5, F9, F11, F22, F91), Inconel 600/625/825 | |
| Duplex & Super Duplex | Duplex 2205, Super Duplex 2507 | |
| Other Materials | Monel 400/K500, Nickel 200/201, Titanium (Grade 2, Grade 5) | |
| Standards & Certifications | ASME / ANSI | ASME B16.5, ASME B16.47 (Series A & B) |
| ASTM | ASTM A182, ASTM A105 | |
| European Standards | DIN 2501, EN 1092-1 | |
| Certifications | ISO 9001, PED 2014/68/EU, NACE MR0175, IBR Approved | |
| Design Features | Wall Thickness | As per ASME B16.5, customized options |
| Face Type | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ) | |
| End Connections | Socket Weld Ends, Beveled Ends, Plain Ends | |
| Tolerance | As per ASME/ANSI standards | |
| Coating & Surface Finish | Anti-Corrosion Coating | Rust Preventive Oil, Black Oxide, Hot-Dip Galvanized |
| Optional Coatings | Epoxy, PTFE, Polyurethane | |
| Surface Finish | Machined, Pickled, Polished, Passivated | |
| Testing & Inspection | Pressure Testing | Hydrostatic, Pneumatic |
| Non-Destructive Testing | Radiography (RT), Ultrasonic (UT), Magnetic Particle (MPI), Dye Penetrant (DPT) | |
| Destructive Testing | Tensile, Hardness, Impact |
Dimensions of Lap Joint Flanges – ASME B16.5
Also commonly known as ANSI B16.5.
| NPS (in) | Class | Flange OD (mm) | Thickness (mm) | Bolt Circle (mm) | Bolt Hole Dia. (mm) | No. of Bolts | Bolt Size |
|---|---|---|---|---|---|---|---|
| 1/2″ | 150 | 90 | 11.2 | 60.3 | 15.9 | 4 | 1/2″ |
| 1/2″ | 300 | 95 | 14.3 | 66.7 | 15.9 | 4 | 1/2″ |
| 1/2″ | 600 | 95 | 14.3 | 66.7 | 15.9 | 4 | 1/2″ |
| 1/2″ | 900 | 120 | 22.3 | 82.6 | 22.2 | 4 | 3/4″ |
| 1/2″ | 1500 | 120 | 22.3 | 82.6 | 22.2 | 4 | 3/4″ |
| 1/2″ | 2500 | 135 | 30.2 | 88.9 | 22.2 | 4 | 3/4″ |
| 3/4″ | 150 | 100 | 12.7 | 69.8 | 15.9 | 4 | 1/2″ |
| 3/4″ | 300 | 115 | 15.9 | 82.6 | 19.1 | 4 | 5/8″ |
| 3/4″ | 600 | 115 | 15.9 | 82.6 | 19.1 | 4 | 5/8″ |
| 3/4″ | 900 | 130 | 25.4 | 88.9 | 22.2 | 4 | 3/4″ |
| 3/4″ | 1500 | 130 | 25.4 | 88.9 | 22.2 | 4 | 3/4″ |
| 3/4″ | 2500 | 140 | 31.8 | 95.3 | 22.2 | 4 | 3/4″ |
| 1″ | 150 | 110 | 14.3 | 79.4 | 15.9 | 4 | 1/2″ |
| 1″ | 300 | 125 | 17.5 | 88.9 | 19.1 | 4 | 5/8″ |
| 1″ | 600 | 125 | 17.5 | 88.9 | 19.1 | 4 | 5/8″ |
| 1″ | 900 | 150 | 28.6 | 101.6 | 25.4 | 4 | 7/8″ |
| 1″ | 1500 | 150 | 28.6 | 101.6 | 25.4 | 4 | 7/8″ |
| 1″ | 2500 | 160 | 35.0 | 108.0 | 25.4 | 4 | 7/8″ |
| 1 1/4″ | 150 | 115 | 15.9 | 88.9 | 15.9 | 4 | 1/2″ |
| 1 1/4″ | 300 | 135 | 19.1 | 98.4 | 19.1 | 4 | 5/8″ |
| 1 1/4″ | 600 | 135 | 20.7 | 98.4 | 19.1 | 4 | 5/8″ |
| 1 1/4″ | 900 | 160 | 28.6 | 111.1 | 25.4 | 4 | 7/8″ |
| 1 1/4″ | 1500 | 160 | 28.6 | 111.1 | 25.4 | 4 | 7/8″ |
| 1 1/4″ | 2500 | 185 | 38.1 | 130.2 | 28.6 | 4 | 1″ |
| 1 1/2″ | 150 | 125 | 17.5 | 98.4 | 15.9 | 4 | 1/2″ |
| 1 1/2″ | 300 | 155 | 20.7 | 114.3 | 22.2 | 4 | 3/4″ |
| 1 1/2″ | 600 | 155 | 22.3 | 123.8 | 28.6 | 4 | 1″ |
| 1 1/2″ | 900 | 180 | 31.8 | 123.8 | 28.6 | 4 | 1″ |
| 1 1/2″ | 1500 | 180 | 31.8 | 123.8 | 28.6 | 4 | 1″ |
| 1 1/2″ | 2500 | 205 | 44.5 | 146.1 | 31.8 | 4 | 1 1/8″ |
| 2″ | 150 | 150 | 19.1 | 120.7 | 19.1 | 4 | 5/8″ |
| 2″ | 300 | 165 | 22.3 | 127.0 | 19.1 | 8 | 5/8″ |
| 2″ | 600 | 165 | 25.4 | 127.0 | 22.2 | 8 | 3/4″ |
| 2″ | 900 | 215 | 38.1 | 165.1 | 25.4 | 8 | 7/8″ |
| 2″ | 1500 | 215 | 38.1 | 165.1 | 25.4 | 8 | 7/8″ |
| 2″ | 2500 | 235 | 50.9 | 177.8 | 28.6 | 8 | 1″ |
| 2 1/2″ | 150 | 180 | 22.3 | 139.7 | 19.1 | 4 | 5/8″ |
| 2 1/2″ | 300 | 190 | 25.4 | 149.2 | 22.2 | 8 | 3/4″ |
| 2 1/2″ | 600 | 190 | 28.6 | 149.2 | 28.6 | 8 | 1″ |
| 2 1/2″ | 900 | 245 | 41.3 | 190.5 | 28.6 | 8 | 1″ |
| 2 1/2″ | 1500 | 245 | 41.3 | 190.5 | 28.6 | 8 | 1″ |
| 2 1/2″ | 2500 | 265 | 57.2 | 196.9 | 31.8 | 8 | 1 1/8″ |
| 3″ | 150 | 190 | 23.9 | 152.4 | 19.1 | 4 | 5/8″ |
| 3″ | 300 | 210 | 28.6 | 168.3 | 22.2 | 8 | 3/4″ |
| 3″ | 600 | 210 | 31.8 | 168.3 | 28.6 | 8 | 1″ |
| 3″ | 900 | 240 | 38.1 | 190.5 | 25.4 | 8 | 7/8″ |
| 3″ | 1500 | 265 | 47.7 | 203.2 | 31.8 | 8 | 1 1/4″ |
| 3″ | 2500 | 305 | 66.7 | 228.6 | 34.9 | 8 | 1 3/8″ |
| 4″ | 150 | 230 | 23.9 | 190.5 | 19.1 | 8 | 3/4″ |
| 4″ | 300 | 255 | 31.8 | 200.0 | 22.2 | 8 | 3/4″ |
| 4″ | 600 | 275 | 38.1 | 215.9 | 31.8 | 8 | 1 1/8″ |
| 4″ | 900 | 290 | 44.5 | 235.0 | 31.8 | 8 | 1 1/8″ |
| 4″ | 1500 | 310 | 54.0 | 241.3 | 31.8 | 8 | 1 1/4″ |
| 4″ | 2500 | 355 | 76.2 | 273.1 | 41.3 | 8 | 1 1/2″ |
| 5″ | 150 | 255 | 23.9 | 215.9 | 22.2 | 8 | 3/4″ |
| 5″ | 300 | 280 | 35.0 | 235.0 | 22.2 | 8 | 3/4″ |
| 5″ | 600 | 330 | 44.5 | 266.7 | 34.9 | 8 | 1 1/4″ |
| 5″ | 900 | 350 | 50.8 | 279.4 | 34.9 | 8 | 1 3/8″ |
| 5″ | 1500 | 375 | 73.1 | 292.1 | 38.1 | 8 | 1 1/2″ |
| 5″ | 2500 | 420 | 92.1 | 323.9 | 47.6 | 8 | 1 7/8″ |
| 6″ | 150 | 280 | 25.4 | 241.3 | 22.2 | 8 | 3/4″ |
| 6″ | 300 | 320 | 36.6 | 269.9 | 25.4 | 12 | 7/8″ |
| 6″ | 600 | 355 | 47.7 | 292.1 | 31.8 | 12 | 1″ |
| 6″ | 900 | 380 | 55.6 | 317.5 | 31.8 | 12 | 1 1/8″ |
| 6″ | 1500 | 395 | 82.6 | 317.5 | 38.1 | 12 | 1 1/2″ |
| 6″ | 2500 | 485 | 108.0 | 368.3 | 54.0 | 8 | 2″ |
| 8″ | 150 | 345 | 28.6 | 298.5 | 22.2 | 8 | 3/4″ |
| 8″ | 300 | 380 | 41.3 | 330.2 | 28.6 | 12 | 1″ |
| 8″ | 600 | 420 | 55.6 | 349.2 | 31.8 | 12 | 1 1/8″ |
| 8″ | 900 | 470 | 63.5 | 393.7 | 38.1 | 12 | 1 1/2″ |
| 8″ | 1500 | 485 | 92.1 | 393.7 | 44.5 | 12 | 1 3/4″ |
| 8″ | 2500 | 550 | 127.0 | 438.2 | 54.0 | 12 | 2″ |
| 10″ | 150 | 405 | 30.2 | 362.0 | 25.4 | 12 | 7/8″ |
| 10″ | 300 | 445 | 47.7 | 387.4 | 28.6 | 16 | 1″ |
| 10″ | 600 | 510 | 63.5 | 431.8 | 35.0 | 16 | 1 1/4″ |
| 10″ | 900 | 545 | 69.9 | 469.9 | 38.1 | 16 | 1 1/2″ |
| 10″ | 1500 | 585 | 108.0 | 482.6 | 50.8 | 12 | 2″ |
| 10″ | 2500 | 675 | 165.1 | 539.8 | 66.7 | 12 | 2 1/2″ |
| 12″ | 150 | 485 | 31.8 | 431.8 | 25.4 | 12 | 7/8″ |
| 12″ | 300 | 520 | 50.8 | 450.8 | 31.8 | 16 | 1 1/8″ |
| 12″ | 600 | 560 | 66.7 | 489.0 | 35.0 | 20 | 1 1/4″ |
| 12″ | 900 | 610 | 79.4 | 533.4 | 38.1 | 20 | 1 1/2″ |
| 12″ | 1500 | 675 | 123.9 | 571.5 | 54.0 | 16 | 2″ |
| 12″ | 2500 | 760 | 184.2 | 619.1 | 73.0 | 12 | 2 3/4″ |
| 14″ | 150 | 535 | 35.0 | 476.3 | 28.6 | 12 | 1″ |
| 14″ | 300 | 585 | 54.0 | 514.4 | 31.8 | 20 | 1 1/8″ |
| 14″ | 600 | 605 | 69.9 | 527.0 | 38.1 | 20 | 1 3/8″ |
| 14″ | 900 | 640 | 85.8 | 558.8 | 41.3 | 20 | 1 1/2″ |
| 14″ | 1500 | 750 | 133.4 | 635.0 | 60.3 | 16 | 2 1/4″ |
| 16″ | 150 | 595 | 36.6 | 539.8 | 28.6 | 16 | 1″ |
| 16″ | 300 | 650 | 57.2 | 571.5 | 35.0 | 20 | 1 1/4″ |
| 16″ | 600 | 685 | 76.2 | 603.3 | 41.3 | 20 | 1 5/8″ |
| 16″ | 900 | 705 | 88.9 | 616.0 | 44.5 | 20 | 1 3/4″ |
| 16″ | 1500 | 825 | 146.1 | 704.8 | 66.7 | 16 | 2 1/2″ |
| 18″ | 150 | 635 | 39.7 | 577.9 | 31.8 | 16 | 1 1/8″ |
| 18″ | 300 | 710 | 60.4 | 628.7 | 35.0 | 24 | 1 1/4″ |
| 18″ | 600 | 745 | 82.6 | 654.1 | 44.5 | 20 | 1 3/4″ |
| 18″ | 900 | 785 | 101.6 | 685.8 | 50.8 | 20 | 2″ |
| 18″ | 1500 | 915 | 162.0 | 774.7 | 73.0 | 16 | 2 3/4″ |
| 20″ | 150 | 700 | 42.9 | 635.0 | 31.8 | 20 | 1 1/4″ |
| 20″ | 300 | 775 | 63.5 | 685.8 | 35.0 | 24 | 1 1/4″ |
| 20″ | 600 | 815 | 88.9 | 723.9 | 44.5 | 24 | 1 3/4″ |
| 20″ | 900 | 855 | 108.0 | 749.3 | 54.0 | 20 | 2 1/8″ |
| 20″ | 1500 | 985 | 177.8 | 831.9 | 79.4 | 16 | 3″ |
| 24″ | 150 | 815 | 47.7 | 749.3 | 35.0 | 20 | 1 1/4″ |
| 24″ | 300 | 915 | 69.9 | 812.8 | 41.3 | 24 | 1 1/2″ |
| 24″ | 600 | 940 | 101.6 | 838.2 | 50.8 | 24 | 2″ |
| 24″ | 900 | 1040 | 139.7 | 901.7 | 66.7 | 20 | 2 1/2″ |
| 24″ | 1500 | 1170 | 203.2 | 990.6 | 92.1 | 16 | 3 1/2″ |
Mechanical Properties
| Property | Value | Unit / Standard |
|---|---|---|
| Tensile Strength | 485 – 750 | MPa (Carbon Steel, Stainless Steel, Alloy Steel) |
| Yield Strength | 170 – 450 | MPa |
| Hardness | 120 – 200 | HB (Brinell) |
| Elongation | ≥ 20 – 30 | % |
| Density | 7.8 – 8.0 | g/cm³ |
| Impact Toughness | ≥ 27 – 70 | J (Charpy, grade-dependent) |
| Modulus of Elasticity (E) | ~200 | GPa |
| Fatigue Strength | 200 – 400 | MPa |
| Corrosion Resistance | Good to Excellent (SS > CS > Alloy Steel) | – |
| Thermal Conductivity | 15 – 50 | W/m·K |
| Coefficient of Thermal Expansion | 11 – 17 ×10⁻⁶ | /°C |
| Yield Ratio (YS/UTS) | 0.40 – 0.65 | – |
| Poisson’s Ratio | 0.27 – 0.30 | – |
| Brinell Hardness Range | 120 – 200 | HB |
| Surface Finish | Serrated / Stock / Smooth finish per ASME B16.5 | – |
| Welding Type | Socket weld or butt weld to pipe (as per application) | – |
| Operating Temperature Range | -46 to 600 | °C (material-dependent) |
| Pressure Rating | Class 150, 300, 600, 900, 1500 | ASME B16.5 Standards |
Chemical Composition
| Element | SS 304 (%) | SS 304L (%) | SS 316 (%) | SS 316L (%) |
|---|---|---|---|---|
| Carbon (C) | ≤ 0.08 | ≤ 0.03 | ≤ 0.08 | ≤ 0.03 |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 | ≤ 0.030 |
| Chromium (Cr) | 18.0 – 20.0 | 18.0 – 20.0 | 16.0 – 18.0 | 16.0 – 18.0 |
| Nickel (Ni) | 8.0 – 10.5 | 8.0 – 12.0 | 10.0 – 14.0 | 10.0 – 14.0 |
| Molybdenum (Mo) | — | — | 2.0 – 3.0 | 2.0 – 3.0 |
| Iron (Fe) | Balance | Balance | Balance | Balance |
Applications of Lap Joint Flanges
Construction &
Infrastructure
Power Generation &
Energy Sector
Manufacturing &
Fabrication
Medical & Laboratory
Equipment
Electrical &
Electronics Assembly
Oil, Gas & Petrochemical
Installations
Do you have questions?
Why choose a Lap Joint Flange over other types?
Can Lap Joint Flanges handle high-pressure environments?
Are Lap Joint Flanges reusable?
Do you offer stub ends along with the flanges?
