Incoloy 800 / 800H / 800HT Lap Joint FlangeASTM B564 · ASME B16.5 · Manufacturer, stockist & exporter, India
Alloy 800 · UNS N08800 / N08810 / N08811 · LJ
An Incoloy 800 / 800H / 800HT lap joint flange is a loose flange that sits behind a stub end welded to the pipe, made from Incoloy 800 / 800H / 800HT to ASTM B564. A lap joint flange rotates freely, making bolt alignment easy on lines that are dismantled often. In corrosive service the flange never touches the fluid, so it can be carbon steel while the stub end is the alloy — a big saving.
- ASTM B564
- ASME B16.5
- EN 10204 3.1 / 3.2
- Export packing
Reviewed by the Kanak Steel & Engineering Co. technical team · Updated October 2026
What is an Incoloy 800 / 800H / 800HT Lap Joint Flange?
- What it is
- A loose flange that sits behind a stub end welded to the pipe
- Material
- ASTM B564
- Dimensions
- ASME B16.5
- Grade
- Incoloy 800 / 800H / 800HT · UNS N08800
- Best at
- Furnaces, petrochemical heaters and high-temperature piping
Incoloy 800 / 800H / 800HT Lap Joint Flange Specification
| Product | Incoloy 800 / 800H / 800HT Lap Joint Flange |
|---|---|
| Material standard | ASTM B564 |
| Dimensional standard | ASME B16.5 |
| Sizes | ½" – 24" (ASME B16.5) · 26" – 60" (ASME B16.47) |
| Pressure class | Class 150, 300, 400, 600, 900, 1500, 2500 · PN 6 – PN 100 |
| Facing | RF · FF · RTJ · tongue & groove |
| Bore | To match pipe schedule (state on order) |
| Testing | PMI · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
When to Choose a Lap Joint Flange
A lap joint flange rotates freely, making bolt alignment easy on lines that are dismantled often. In corrosive service the flange never touches the fluid, so it can be carbon steel while the stub end is the alloy — a big saving.
- Used with a stub end (MSS SP-43 or ASME B16.9)
- Flange can be a cheaper material than the stub end
- Lower pressure rating than a weld neck
Incoloy 800 / 800H / 800HT Lap Joint Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 30.0 – 35.0 |
| Chromium | 19.0 – 23.0 |
| Iron | 39.5 min |
| Carbon | 0.10 max (800) · 0.05 – 0.10 (800H) |
| Aluminium | 0.15 – 0.60 |
| Titanium | 0.15 – 0.60 |
| Copper | 0.75 max |
| Manganese | 1.5 max |
Incoloy 800 / 800H / 800HT Lap Joint Flange Mechanical Properties
| Annealed plate | Value |
|---|---|
| Tensile strength | 520 MPa · 75 ksi (800) · 450 MPa · 65 ksi (800H) |
| Yield strength 0.2% | 205 MPa · 30 ksi (800) · 170 MPa · 25 ksi (800H) |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the Incoloy 800 / 800H / 800HT grade page.
Other Incoloy 800 / 800H / 800HT flanges
Incoloy 800 / 800H / 800HT Lap Joint Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiIncoloy 800 / 800H / 800HT Lap Joint Flange dimensions — ASME B16.5 Class 150 & 300
Outside diameter, thickness and bolting are set by size and class. Values in mm; thickness excludes the 1.6 mm raised face.
| NPS | Cl 150 OD | Cl 150 thickness | Cl 150 bolt circle | Cl 150 bolts | Cl 300 OD | Cl 300 thickness | Cl 300 bolt circle | Cl 300 bolts |
|---|---|---|---|---|---|---|---|---|
| ½" | 90 | 9.6 | 60.3 | 4 × ½" | 95 | 12.7 | 66.7 | 4 × ½" |
| 1" | 110 | 12.7 | 79.4 | 4 × ½" | 125 | 15.9 | 88.9 | 4 × ⅝" |
| 1½" | 125 | 15.9 | 98.4 | 4 × ½" | 155 | 19.1 | 114.3 | 4 × ¾" |
| 2" | 150 | 17.5 | 120.7 | 4 × ⅝" | 165 | 20.7 | 127.0 | 8 × ⅝" |
| 3" | 190 | 22.3 | 152.4 | 4 × ⅝" | 210 | 27.0 | 168.3 | 8 × ¾" |
| 4" | 230 | 22.3 | 190.5 | 8 × ⅝" | 255 | 30.2 | 200.0 | 8 × ¾" |
| 6" | 280 | 23.9 | 241.3 | 8 × ¾" | 320 | 35.0 | 269.9 | 12 × ¾" |
| 8" | 345 | 27.0 | 298.5 | 8 × ¾" | 380 | 39.7 | 330.2 | 12 × ⅞" |
| 10" | 405 | 28.6 | 362.0 | 12 × ⅞" | 445 | 46.1 | 387.4 | 16 × 1" |
| 12" | 485 | 30.2 | 431.8 | 12 × ⅞" | 520 | 49.3 | 450.8 | 16 × 1⅛" |
Full chart: ASME B16.5 flange dimensions.
Incoloy 800 / 800H / 800HT Lap Joint Flange — questions buyers ask
Does a lap joint flange have to be the same alloy as the pipe?
No. Only the stub end touches the fluid, so the backing flange is often carbon steel, saving the cost of an alloy forging.
Which standard covers Incoloy 800 / 800H / 800HT lap joint flanges?
The material is ASTM B564; dimensions follow ASME B16.5. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Incoloy 800 / 800H / 800HT lap joint flange?
The alloy price, the size and pressure class, quantity, and the testing and documents required. Send your list and we quote the same working day.
What documents do you supply?
EN 10204 3.1 mill certificates as standard, 3.2 with third-party inspection on request, plus dimensional and PMI reports.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026