ASTM A333 Gr 6 CapASTM A420 · ASME B16.9 · Manufacturer, stockist & exporter, India
SA-333 Gr 6 · Low-temperature carbon steel pipe
An ASTM A333 Gr 6 cap is a fitting that closes the end of a pipe, for use with ASTM A333 Gr 6 pipe. ASTM A333 Gr 6 itself is a pipe or plate specification, so the matching cap is made to ASTM A420 WPL6 (buttweld) · ASTM A350 LF2 (forged) — which is what we supply for A333 Gr 6 lines. 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 A420
- 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 ASTM A333 Gr 6 Cap?
- What it is
- A fitting that closes the end of a pipe
- Material
- ASTM A420 WPL6 (buttweld) · ASTM A350 LF2 (forged)
- Dimensions
- ASME B16.9 · B16.11
- Grade
- ASTM A333 Gr 6
- Best at
- Cold-climate and refrigerated piping down to −45 °C
ASTM A333 Gr 6 Cap Specification
| Product | ASTM A333 Gr 6 Cap |
|---|---|
| Material standard | ASTM A420 WPL6 (buttweld) · ASTM A350 LF2 (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 | Chemical & mechanical per heat · NDT · impact where specified |
| 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
ASTM A333 Gr 6 Cap Chemical Composition
| Element | Weight % |
|---|---|
| Carbon | 0.30 max |
| Manganese | 0.29 – 1.06 |
| Silicon | 0.10 min |
| Phosphorus | 0.025 max |
| Sulphur | 0.025 max |
ASTM A333 Gr 6 Cap Mechanical Properties
| Minimum values | Value |
|---|---|
| Tensile strength | 415 MPa · 60 ksi |
| Yield strength 0.2% | 240 MPa · 35 ksi |
| Elongation | 30% |
| Charpy impact | Tested at −45 °C |
Full chemistry, properties and equivalents are on the ASTM A333 Gr 6 grade page.
Other ASTM A333 Gr 6 pipe fittings
ASTM A333 Gr 6 Caps for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A333 Gr 6 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.
ASTM A333 Gr 6 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 ASTM A333 Gr 6 caps?
The material is ASTM A420 WPL6 (buttweld) · ASTM A350 LF2 (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 ASTM A333 Gr 6 cap?
The steel price, the size and schedule or 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