Inconel 718 Weld Neck FlangeASME B16.5 · Manufacturer, trader & exporter, India
Alloy 718 · UNS N07718 · WNRF
An Inconel 718 weld neck flange is a flange with a long tapered hub that is butt-welded to the pipe, made from Inconel 718 to project / purchase specification dependent. Choose a weld neck flange for high pressure, high or low temperature and cyclic loading. The tapered hub moves stress away from the flange face, and the full-penetration butt weld can be radiographed.
- Inconel 718
- 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 Inconel 718 Weld Neck Flange?
- What it is
- A flange with a long tapered hub that is butt-welded to the pipe
- Material
- project / purchase specification dependent
- Dimensions
- ASME B16.5 · B16.47
- Grade
- Inconel 718 · UNS N07718
- Best at
- Very high strength at temperatures up to about 650 °C
Inconel 718 Weld Neck Flange Specification
| Product | Inconel 718 Weld Neck Flange |
|---|---|
| Material standard | project / purchase specification dependent |
| Dimensional standard | ASME B16.5 · B16.47 |
| 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 (as specified in the PO) · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 or 3.2 on request / as specified in the PO |
When to Choose a Weld Neck Flange
Choose a weld neck flange for high pressure, high or low temperature and cyclic loading. The tapered hub moves stress away from the flange face, and the full-penetration butt weld can be radiographed.
- Bore must match the pipe schedule — state it on the order
- Hub length and taper per ASME B16.5 / B16.47 tables
- Most common facing: raised face; RTJ for high-pressure classes
More on choosing: Weld neck flange guide.
Inconel 718 Weld Neck Flange: Why 718 for weld neck flanges
Choose a weld neck flange for high pressure, high or low temperature and cyclic loading. The tapered hub moves stress away from the flange face, and the full-penetration butt weld can be radiographed. In Inconel 718, the choice usually comes down to the medium and temperature — the rows here are the points buyers check for this exact combination.
| Why this grade | Nickel-alloy flanges are used where acids, chlorides or heat defeat stainless. Inconel 718 is picked for very high strength at temperatures up to about 650 °C. |
|---|---|
| Typical service | Oil & gas — Wellhead parts, hangers and high-strength bolting. |
| Bolting | B7 (coated), B8M or nickel-alloy studs in Inconel 718 (bar to ASTM B637, where applicable), as the project specifies |
| Welding to carbon steel | A nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel |
| Matching filler | ERNiFeCr-2 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 718 Weld Neck Flange Chemical Composition
| Element | Weight % (producer reference) |
|---|---|
| Nickel (+Co) | 50.00 – 55.00 |
| Chromium | 17.00 – 21.00 |
| Iron | Balance |
| Niobium (+Ta) | 4.75 – 5.50 |
| Molybdenum | 2.80 – 3.30 |
| Titanium | 0.65 – 1.15 |
| Aluminium | 0.20 – 0.80 |
| Cobalt | 1.00 max |
Inconel 718 Weld Neck Flange Mechanical Properties
No specification requirement is asserted for this product form; requirements are to the purchase specification.
Full chemistry, properties and equivalents are on the Inconel 718 grade page.
Other Inconel 718 flanges
Inconel 718 Weld Neck 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.
Inconel 718 Weld Neck Flange — questions buyers ask
Why is the bore important on a weld neck flange?
The flange bore is machined to the inside diameter of the pipe schedule, so the weld is smooth inside. A wrong bore leaves a step that disturbs flow and complicates the weld.
Can Inconel 718 weld neck flanges be welded to carbon steel?
Yes — a nickel-base filler such as ERNiCr-3 (or ERNiCrMo-3) is used when joining it to carbon steel.
Which standard covers Inconel 718 weld neck flanges?
The finished flange specification is project / purchase specification dependent, so none is named here; dimensions follow ASME B16.5 · B16.47. State the flange specification your project requires on the purchase order.
What decides the price of a Inconel 718 weld neck 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.
Can you supply Inconel 718 weld neck flanges to NACE MR0175?
Yes. Inconel 718 is listed in NACE MR0175 / ISO 15156-3 within its limits; state NACE compliance on the order and it is confirmed on the certificate.
What documents do you supply?
EN 10204 3.1 or 3.2 certificates available on request / as specified in the PO; dimensional reports as required. PMI can be arranged depending on product and requirements, as specified in the PO.
Sources: the ASTM / ASME specifications named on this page and producer datasheets · Last updated October 2026