Inconel 718 CapASME B16.9 · Manufacturer, trader & exporter, India
Alloy 718 · UNS N07718
An Inconel 718 cap is a fitting that closes the end of a pipe, made from Inconel 718 to a specification not yet established (buttweld) · a specification not yet established (forged). Buttweld caps are dished ends welded to the pipe; forged caps are threaded or socket-weld. Used at dead ends and future connection points.
- Inconel 718
- ASME B16.9
- 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 Cap?
- What it is
- A fitting that closes the end of a pipe
- Material
- a specification not yet established (buttweld) · a specification not yet established (forged)
- Dimensions
- ASME B16.9 · B16.11
- Grade
- Inconel 718 · UNS N07718
- Best at
- Very high strength at temperatures up to about 650 °C
Inconel 718 Cap Specification
| Product | Inconel 718 Cap |
|---|---|
| Material standard | a specification not yet established (buttweld) · a specification not yet established (forged) |
| Dimensional standard | ASME B16.9 · B16.11 |
| Sizes | Buttweld ½" – 48" · forged ⅛" – 4" |
| Wall / class | Schedule to match pipe · Class 3000 / 6000 (forged) |
| Ends | Bevelled to ASME B16.25 |
| 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 Cap
Buttweld caps are dished ends welded to the pipe; forged caps are threaded or socket-weld. Used at dead ends and future connection points.
- Buttweld dished caps
- Threaded and socket-weld caps
- Wall to match the pipe
More on choosing: Cap guide.
Inconel 718 Cap: Why 718 for caps
Buttweld caps are dished ends welded to the pipe; forged caps are threaded or socket-weld. Used at dead ends and future connection points. 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 fittings match nickel-alloy pipe in aggressive media. 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. |
| 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 Cap 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 Cap 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 pipe fittings
Inconel 718 Cap dimensions — ASME B16.9
Values in mm, the same for every material; the wall thickness matches the pipe schedule.
| NPS | OD | Cap length E |
|---|---|---|
| ½" | 21.3 | 25 |
| ¾" | 26.7 | 25 |
| 1" | 33.4 | 38 |
| 1½" | 48.3 | 38 |
| 2" | 60.3 | 38 |
| 3" | 88.9 | 51 |
| 4" | 114.3 | 64 |
| 6" | 168.3 | 89 |
| 8" | 219.1 | 102 |
| 10" | 273.1 | 127 |
| 12" | 323.9 | 152 |
| 16" | 406.4 | 178 |
| 20" | 508.0 | 229 |
| 24" | 610.0 | 267 |
Full chart: ASME B16.9 fitting dimensions.
Inconel 718 Cap — questions buyers ask
Can a cap take full line pressure?
Yes — a buttweld cap of matching schedule is rated like the pipe it closes.
Can Inconel 718 caps 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 caps?
The material is a specification not yet established (buttweld) · a specification not yet established (forged); dimensions follow ASME B16.9 · B16.11. Always state both on your purchase order, with the edition if your project specifies one.
What decides the price of a Inconel 718 cap?
The alloy price, the size and schedule or class, quantity, and the testing and documents required. Send your list and we quote the same working day.
Can you supply Inconel 718 caps 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