Inconel 625 Socket Weld FlangeASTM B564 · ASME B16.5 · Manufacturer, stockist & exporter, India
Alloy 625 · UNS N06625 · SWRF
An Inconel 625 socket weld flange is a flange with a counterbore socket into which the pipe is inserted and fillet-welded, made from Inconel 625 to ASTM B564. Socket weld flanges suit small-bore, high-pressure lines, usually 2" and under. A 1.6 mm (1/16") expansion gap is left at the bottom of the socket before welding.
- 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 Inconel 625 Socket Weld Flange?
- What it is
- A flange with a counterbore socket into which the pipe is inserted and fillet-welded
- Material
- ASTM B564
- Dimensions
- ASME B16.5
- Grade
- Inconel 625 · UNS N06625
- Best at
- Seawater, high strength and high temperature in one alloy
Inconel 625 Socket Weld Flange Specification
| Product | Inconel 625 Socket Weld 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 Socket Weld Flange
Socket weld flanges suit small-bore, high-pressure lines, usually 2" and under. A 1.6 mm (1/16") expansion gap is left at the bottom of the socket before welding.
- Leave a 1.6 mm gap before welding
- Not recommended where crevice corrosion is a concern
- Bore to match pipe schedule
More on choosing: Socket weld flange guide.
Inconel 625 Socket Weld Flange: Why 625 for socket weld flanges
Socket weld flanges suit small-bore, high-pressure lines, usually 2" and under. A 1.6 mm (1/16") expansion gap is left at the bottom of the socket before welding. In Inconel 625, 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 625 is picked for seawater, high strength and high temperature in one alloy. |
|---|---|
| Typical service | Offshore & subsea — Risers, flowlines and clad pipe. |
| B16.5 material group | 3.8 |
| Bolting | B7 (coated), B8M or nickel-alloy studs such as Inconel 625 from ASTM B446, 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 | ERNiCrMo-3 (AWS A5.14) |
| Sour service | Listed in NACE MR0175 / ISO 15156-3 within its limits — state it on the order |
Inconel 625 Socket Weld Flange Chemical Composition
| Element | Weight % |
|---|---|
| Nickel | 58.0 min |
| Chromium | 20.0 – 23.0 |
| Molybdenum | 8.0 – 10.0 |
| Niobium + Tantalum | 3.15 – 4.15 |
| Iron | 5.0 max |
| Carbon | 0.10 max |
| Manganese | 0.50 max |
| Silicon | 0.50 max |
Inconel 625 Socket Weld Flange Mechanical Properties
| Grade 1 annealed plate | Value |
|---|---|
| Tensile strength | 827 MPa · 120 ksi |
| Yield strength 0.2% | 414 MPa · 60 ksi |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the Inconel 625 grade page.
Other Inconel 625 flanges
Inconel 625 Socket Weld Flanges for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiInconel 625 Socket Weld 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 625 Socket Weld Flange — questions buyers ask
Why leave a gap in a socket weld?
The gap lets the pipe expand during welding without cracking the fillet weld. ASME B31.3 requires it.
What pressure rating does a Inconel 625 socket weld flange have?
It depends on class and temperature. Inconel 625 forgings are in ASME B16.5 material group 3.8; read your class column in that group's table at the design temperature.
Can Inconel 625 socket weld 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 625 socket weld 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 Inconel 625 socket weld 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 625 socket weld flanges to NACE MR0175?
Yes. Inconel 625 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 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