ASTM A106 Gr B CapASTM A234 · ASME B16.9 · Manufacturer, stockist & exporter, India
SA-106 Gr B · Seamless carbon steel pipe
An ASTM A106 Gr B cap is a fitting that closes the end of a pipe, for use with ASTM A106 Gr B pipe. ASTM A106 Gr B itself is a pipe or plate specification, so the matching cap is made to ASTM A234 WPB (buttweld) · ASTM A105 (forged) — which is what we supply for A106 B 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 A234
- 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 A106 Gr B Cap?
- What it is
- A fitting that closes the end of a pipe
- Material
- ASTM A234 WPB (buttweld) · ASTM A105 (forged)
- Dimensions
- ASME B16.9 · B16.11
- Grade
- ASTM A106 Gr B
- Best at
- High-temperature process and steam piping in refineries and power plants
ASTM A106 Gr B Cap Specification
| Product | ASTM A106 Gr B Cap |
|---|---|
| Material standard | ASTM A234 WPB (buttweld) · ASTM A105 (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 A106 Gr B Cap Chemical Composition
| Element | Weight % |
|---|---|
| Carbon | 0.30 max |
| Manganese | 0.29 – 1.06 |
| Silicon | 0.10 min |
| Phosphorus | 0.035 max |
| Sulphur | 0.035 max |
| Chromium | 0.40 max |
| Copper | 0.40 max |
| Nickel | 0.40 max |
ASTM A106 Gr B Cap Mechanical Properties
| Minimum values (elongation varies with wall) | Value |
|---|---|
| Tensile strength | 415 MPa · 60 ksi |
| Yield strength 0.2% | 240 MPa · 35 ksi |
| Elongation | 30% |
Full chemistry, properties and equivalents are on the ASTM A106 Gr B grade page.
Other ASTM A106 Gr B pipe fittings
ASTM A106 Gr B Caps for export
FOB / CIF · Nhava Sheva (JNPT), MumbaiASTM A106 Gr B 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 A106 Gr B 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 A106 Gr B caps?
The material is ASTM A234 WPB (buttweld) · ASTM A105 (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 A106 Gr B 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