Monel 400 CapASTM B366 · ASME B16.9 · Manufacturer, stockist & exporter, India
Alloy 400 · UNS N04400
A Monel 400 cap is a fitting that closes the end of a pipe, made from Monel 400 to ASTM B366 WPNC (buttweld) · ASTM B564 (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.
- ASTM B366
- 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 a Monel 400 Cap?
- What it is
- A fitting that closes the end of a pipe
- Material
- ASTM B366 WPNC (buttweld) · ASTM B564 (forged)
- Dimensions
- ASME B16.9 · B16.11
- Grade
- Monel 400 · UNS N04400
- Best at
- Seawater, hydrofluoric acid and marine service
Monel 400 Cap Specification
| Product | Monel 400 Cap |
|---|---|
| Material standard | ASTM B366 WPNC (buttweld) · ASTM B564 (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 · dimensional · NDT and IGC on request |
| Documents | EN 10204 3.1 · 3.2 with third-party inspection |
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
Monel 400 Cap Chemical Composition
| Element | Weight % |
|---|---|
| Nickel (+Co) | 63.0 min |
| Copper | 28.0 – 34.0 |
| Iron | 2.5 max |
| Manganese | 2.0 max |
| Carbon | 0.3 max |
| Silicon | 0.5 max |
| Sulphur | 0.024 max |
Monel 400 Cap Mechanical Properties
| Annealed plate | Value |
|---|---|
| Tensile strength | 480 MPa · 70 ksi |
| Yield strength 0.2% | 195 MPa · 28 ksi |
| Elongation | 35% |
Full chemistry, properties and equivalents are on the Monel 400 grade page.
Other Monel 400 pipe fittings
Monel 400 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.
Monel 400 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.
Which standard covers Monel 400 caps?
The material is ASTM B366 WPNC (buttweld) · ASTM B564 (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 Monel 400 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 Monel 400 caps to NACE MR0175?
Yes. Monel 400 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