ASTM A106 Grade B Carbon Steel Fittings – A234 WPB & A105
Quick answer: ASTM A106 Grade B is a specification for seamless carbon steel pipe, not fittings. The fittings used with A106 Gr B pipe are made to matching material specifications:
- Butt-weld fittings (elbows, tees, reducers, caps) – ASTM A234 WPB, dimensions to ASME B16.9.
- Forged socket-weld and threaded fittings – ASTM A105, dimensions to ASME B16.11.
Both have chemistry and strength compatible with A106 Grade B, so they weld and perform together in the same piping system. ASC LLP supplies complete A106 Grade B fittings packages – pipe, A234 WPB butt-weld fittings, A105 forged fittings and A105 flanges – with EN 10204 3.1 certificates.
A106 Gr B Pipe vs A234 WPB vs A105 Fittings
| Property | A106 Gr B (pipe) | A234 WPB (butt-weld) | A105 (forged) |
| Product | Seamless pipe | Seamless / welded butt-weld fittings | Forgings – socket-weld, threaded, flanges |
| Dimensional standard | ASME B36.10M | ASME B16.9, B16.28, MSS SP-75 | ASME B16.11, B16.5 |
| Tensile strength | 415 MPa min (60 ksi) | 415 – 585 MPa (60 – 85 ksi) | 485 MPa min (70 ksi) |
| Yield strength | 240 MPa min (35 ksi) | 240 MPa min (35 ksi) | 250 MPa min (36 ksi) |
| Hardness | – | 197 HB max | 187 HB max |
| Carbon (C) | 0.30 max | 0.30 max | 0.35 max |
| Manganese (Mn) | 0.29 – 1.06 | 0.29 – 1.06 | 0.60 – 1.05 |
Why Use A234 WPB and A105 Fittings with A106 Grade B Pipe?
- Matching chemistry and strength: similar carbon and manganese limits give good weldability and equal strength across the joint.
- Code acceptance: A106 B pipe, A234 WPB and A105 are the standard carbon-steel combination in ASME B31.1 and B31.3 piping.
- High-temperature service: suited to steam, hot water, oil and gas lines in refineries and power plants.
- Full range: butt-weld fittings for larger lines, forged fittings for small-bore branches, vents and drains.
- Economical: the lowest-cost option for non-corrosive service; use galvanising, coating or lining where corrosion is a concern.
Need higher strength or low-temperature toughness? See A860 WPHY 52 and A420 WPL6 fittings.
A106 Grade B Fitting Types, Standards & Sizes
| Fitting type | Material | Standard | Sizes / class |
| Elbows (45°, 90°, 180°, LR / SR) | A234 WPB | ASME B16.9 / B16.28 | 1/2″ – 48″, SCH 10 – XXS |
| Tees (equal / reducing), crosses | A234 WPB | ASME B16.9 | 1/2″ – 48″, SCH 10 – XXS |
| Reducers (concentric / eccentric) | A234 WPB | ASME B16.9 | 1/2″ – 48″, SCH 10 – XXS |
| Caps, stub ends | A234 WPB | ASME B16.9 | 1/2″ – 48″ |
| Socket-weld fittings | A105 | ASME B16.11 | 1/8″ – 4″, Class 3000 / 6000 / 9000 |
| Threaded fittings | A105 | ASME B16.11 | 1/8″ – 4″, Class 2000 / 3000 / 6000 |
| Flanges | A105 | ASME B16.5 / B16.47 | 1/2″ – 60″, Class 150 – 2500 |
Butt-weld fitting wall thickness is matched to the pipe schedule (SCH 10, 20, 40/STD, 80/XS, 160, XXS).
ASTM A106 Grade B Pipe – Mechanical Properties
| Property | Requirement |
| Tensile strength | 415 MPa (60 ksi) min |
| Yield strength | 240 MPa (35 ksi) min |
| Elongation (longitudinal) | As per ASTM A106 table (≈ 30% for standard specimen) |
For fitting properties see the comparison table above, or the A234 WPB and A105 pages.
Specifications
| Item | Details |
| Pipe | ASTM A106 / ASME SA106 Grade B, seamless |
| Butt-weld fittings | ASTM A234 / ASME SA234 WPB (WPC for higher strength) |
| Forged fittings & flanges | ASTM A105 / ASME SA105 |
| Dimensions | ASME B16.9, B16.28, B16.11, B16.5, MSS SP-75 / SP-97 |
| Ends | Bevelled (butt-weld), socket-weld, threaded (NPT / BSPT) |
| Certificate | EN 10204 3.1; NACE MR0175, IBR and third-party inspection on request |
Chemical Composition – A106 Gr B, A234 WPB, A105 (wt %)
| Element | A106 Gr B | A234 WPB | A105 |
| Carbon (C) | 0.30 max | 0.30 max | 0.35 max |
| Manganese (Mn) | 0.29 – 1.06 | 0.29 – 1.06 | 0.60 – 1.05 |
| Phosphorus (P) | 0.035 max | 0.050 max | 0.035 max |
| Sulphur (S) | 0.035 max | 0.058 max | 0.040 max |
| Silicon (Si) | 0.10 min | 0.10 min | 0.10 – 0.35 |
| Chromium (Cr) | 0.40 max | 0.40 max | 0.30 max |
| Copper (Cu) | 0.40 max | 0.40 max | 0.40 max |
| Molybdenum (Mo) | 0.15 max | 0.15 max | 0.12 max |
| Nickel (Ni) | 0.40 max | 0.40 max | 0.40 max |
| Vanadium (V) | 0.08 max | 0.08 max | 0.08 max |
Physical Properties of Carbon Steel Fittings
| Property | Value (approx.) |
| Density | 7.85 g/cm³ |
| Melting range | ≈ 1,425 – 1,530 °C |
| Thermal conductivity | ≈ 50 W/m·K |
| Coefficient of thermal expansion | ≈ 11.7 µm/m·°C |
| Modulus of elasticity | ≈ 200 GPa |
Applications of A106 Grade B Pipe Fittings
| Industry | Typical uses |
| Oil & gas / refineries | Process, utility and hydrocarbon lines |
| Power generation | Steam, feed-water, condensate and cooling-water piping |
| Petrochemical & chemical | Plant piping for non-corrosive fluids |
| Industrial plants | Compressed air, hot water, fire-water and utility systems |
Why Buy A106 Grade B Pipe & Fittings from ASC LLP?
- One-stop package: A106 Gr B pipe, A234 WPB butt-weld fittings, A105 forged fittings and A105 flanges from one source.
- Certified material: EN 10204 3.1 certificates with full heat traceability; IBR and NACE on request.
- All sizes and schedules to ASME B16.9 and B16.11.
- Inspection: PMI, dimensional checks and third-party inspection on request.
- Export packing and worldwide delivery.
Send your fitting list (type, size, schedule or class, quantity) to sales@amardeepsteel.com or call 022-67439130.
Frequently Asked Questions – A106 Grade B Fittings
Are there ASTM A106 Grade B fittings?
ASTM A106 covers seamless pipe only. Fittings for A106 Grade B pipe are made to ASTM A234 WPB (butt-weld, ASME B16.9) and ASTM A105 (forged socket-weld and threaded, ASME B16.11). They are often ordered as “A106 Grade B fittings”.
What is the fitting material for A106 Grade B pipe?
Use ASTM A234 WPB for butt-weld elbows, tees, reducers and caps, and ASTM A105 for forged socket-weld and threaded fittings and flanges.
What is the difference between A234 WPB and A105?
A234 WPB covers wrought butt-weld fittings made from pipe or plate, with 415–585 MPa tensile strength. A105 covers carbon steel forgings – socket-weld and threaded fittings and flanges – with 485 MPa minimum tensile strength.
What are the mechanical properties of ASTM A106 Grade B?
ASTM A106 Grade B pipe has a minimum tensile strength of 415 MPa (60 ksi) and a minimum yield strength of 240 MPa (35 ksi).
Can A234 WPB fittings be used with A53 Grade B pipe?
Yes. A234 WPB is the usual butt-weld fitting material for both A106 Grade B and A53 Grade B carbon steel pipe.
Global Reach
ASC LLP supplies carbon steel pipes, fittings and flanges to oil & gas, power and process-industry customers worldwide, with prompt delivery and full documentation. Buyers in the USA, Europe, the Middle East and Asia rely on our A106 Grade B pipe fittings for certified material and traceability.
Countries We Export To
UNITED STATES, EUROPE, UK, UAE, SAUDI ARABIA, OMAN, KUWAIT, JORDAN, QATAR, INDONESIA, MALAYSIA, BRAZIL, SPAIN, ITALY, FRANCE, GERMANY, BAHRAIN, SRI LANKA, AZERBAIJAN, AUSTRALIA, AUSTRIA, PHILIPPINES, TURKEY, RUSSIA, IRAN, IRAQ, CANADA, KOREA, JAPAN, YEMEN, FINLAND, ZIMBABWE, HUNGARY, PORTUGAL, VIETNAM, MOROCCO, THAILAND, SOUTH AFRICA, MEXICO, SINGAPORE, GREECE, KUWAIT, POLAND, NEW ZEALAND, SWEDEN, SWITZERLAND, BELGIUM, BHUTAN, BANGLADESH, TAIWAN, ROMANIA, CAMBODIA, KAZAKHSTAN, AFGHANISTAN.
