Steel A106 Grade B-A (Solution annealed)
Temper
ASTM A106 Grade B · UNS K03006
Softest condition — pick for heavy cold bending, flaring or subsequent machining of fittings from pipe.
Values for the A condition
Other A106 Grade B tempers and conditions
A106 Grade B is listed in 3 conditions; see the grade overview at A106 Grade B.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
AThis page Solution annealed | Softest condition — pick for heavy cold bending, flaring or subsequent machining of fittings from pipe. | 265 | 440 | 36 | 131 HB | 10 % IACS |
Normalized | Choose when uniform fine-grained structure and better low-temperature toughness are required (impact-tested / low-temp supplementary orders). | 300 | 470 | 34 | 140 HB | — |
Cold Drawn Seamless, stress relieved per A106 | Tighter tolerances and smoother bore for hydraulic/instrument lines; A106 requires heat treatment after cold drawing, giving higher yield but lower ductility. | 420 | 550 | 20 | 170 HB | — |
What is A106 Grade B-A?
A106 Grade B-A is A106 Grade B in the A temper — softest condition — pick for heavy cold bending, flaring or subsequent machining of fittings from pipe. A106 Grade B-A has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 92% of steel grades. Elongation at break is 36% and the elastic modulus is 200 GPa (29 Msi). A106 Grade B-A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,470°C (2,678 °F).
Advantages
- Ductile — tolerates forming and impact — 36%, better than 98% of steel grades
- Conducts heat well — 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades
- Readily welded — 95/100, better than 97% of steel grades
- Forms and bends easily — 80/100, better than 93% of steel grades
- High electrical conductivity — 10 % IACS, better than 83% of steel grades
Limitations
- Hard to polish — 40/100, worse than 96% of steel grades
- Low strength — 265 MPa (38.4 ksi), worse than 92% of steel grades
A106 Grade B-A properties
Typical room-temperature values for A106 Grade B-A; 22 are specific to this condition. Other listed values are A106 Grade B reference data and may not represent this condition. Bars are the position among steel grades.
Physical3
A106 Grade B-A has a density of 7.85 g/cm³ (0.284 lb/in³), heavier than 56% of steel grades. It melts at 1,470°C (2,678 °F).
Mechanical16
A106 Grade B-A has a yield strength of 265 MPa (38.4 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 92% of steel grades. Elongation at break is 36% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
A106 Grade B-A is rated for continuous service to 425°C (797 °F). It conducts heat at 52 W/m·K (30 BTU/hr·ft·°F), better than 98% of steel grades. Thermal expansion is 11.7 µm/m·K (6.5 µin/in·°F).
Electrical3
A106 Grade B-A conducts electricity at 10 % IACS, better than 83% of steel grades.
Chemical & Environmental3
Corrosion resistance is not recommended (10/100), worse than 86% of steel grades.
Sustainability4
Producing a kilogram of A106 Grade B-A takes about 25 MJ of energy and emits 2 kg of CO₂ — less than 82% of steel grades. Typical recycled content is 25%.
Manufacturability7
A106 Grade B-A's machinability is good (57/100, better than 71% of steel grades); weldability excellent (95/100); formability very good (80/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with A106 Grade B-A
Is A106 Grade B easy to machine?
Machines like 1020/1025 — free-machining ratings ~65 % of AISI 1212; use sharp tooling and generous feed to avoid built-up edge on the softer as-rolled pipe.
Can A106 Grade B be welded?
Excellent weldability (CE ≈ 0.40); SMAW E7018 / GTAW ER70S-2 root, no preheat under ~25 mm wall, PWHT per ASME B31 above 19 mm.
Can A106 Grade B be formed, bent or molded?
Hot or cold bends to 3D–5D radius are routine; cold bends over 5 % strain should be normalized or stress relieved for code piping.
What surface finishes work on A106 Grade B?
No corrosion resistance of its own — specify shot blast plus epoxy/zinc primer, hot-dip galvanizing or internal lining for wet service.
A106 Grade B chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| C0.30 max per ASTM A106 Gr B | ≤ 0.3 | 0.22 |
| Mn | 0.29 – 1.06 | 0.75 |
| P | ≤ 0.04 | 0.02 |
| S | ≤ 0.04 | 0.01 |
| Sikilled steel, 0.10 min | ≥ 0.1 | 0.25 |
| Cr | ≤ 0.4 | 0.08 |
| Cu | ≤ 0.4 | 0.1 |
| Mo | ≤ 0.15 | 0.02 |
| Ni | ≤ 0.4 | 0.08 |
| VCr+Cu+Mo+Ni+V ≤ 1.00 total | ≤ 0.08 | 0.01 |
| Fe | balance | — |
A106 Grade B-A — frequently asked
What is A106 Grade B-A used for?
A106 Grade B-A is typically used for high-temperature piping, power plants, refineries and steam lines. In short: seamless high-temperature pipe; code piping standard; stronger than A53 service.
What is the yield strength of A106 Grade B-A?
A106 Grade B-A has a typical yield strength of 265 MPa (38.4 ksi) and a tensile strength of 440 MPa (63.8 ksi) — weaker than 92% of steel grades. Strength varies by condition: see the 3 listed tempers.
Is A106 Grade B-A easy to machine?
Reasonably — machinability is rated good (57/100, better than 71% of steel grades). Machines like 1020/1025 — free-machining ratings ~65 % of AISI 1212; use sharp tooling and generous feed to avoid built-up edge on the softer as-rolled pipe.
Can A106 Grade B-A be welded?
Yes — weldability is rated excellent (95/100). Excellent weldability (CE ≈ 0.40); SMAW E7018 / GTAW ER70S-2 root, no preheat under ~25 mm wall, PWHT per ASME B31 above 19 mm.
What surface finishes work on A106 Grade B-A?
No corrosion resistance of its own — specify shot blast plus epoxy/zinc primer, hot-dip galvanizing or internal lining for wet service.
Can A106 Grade B-A be formed, bent or molded?
Hot or cold bends to 3D–5D radius are routine; cold bends over 5 % strain should be normalized or stress relieved for code piping.
What is the maximum service temperature of A106 Grade B-A?
A106 Grade B-A is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASTM A106/A106M — Seamless Carbon Steel Pipe for High-Temperature Service — ASTM International (2019)
- ASME BPVC Section II Part D — Material Properties — ASME (2023)
- ASME B31.3 Process Piping — ASME (2022)
- ASM Handbook Vol.1 — Properties and Selection: Irons, Steels — ASM International (1990)
- GB/T 8163 / GB/T 8162 (20 ) — SAC (2018)
- NACE MR0175 / ISO 15156-2 — NACE/ISO (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.