ASTM A106 is for high-pressure, high-temperature applications like pipelines, while ASTM A179 is for low-pressure, low-temperature heat transfer applications like condensers and heat exchangers. A106 is typically hot-rolled and available in multiple grades (A, B, and C), whereas A179 is a cold-drawn, low-carbon steel tubing with a minimum wall thickness for its specified uses.
Chemical Composition Comparison Table
| Chemical Composition (%) |
A179 Seamless Steel Pipe |
A106 Grade B Seamless Steel Pipe (Typical Values) |
| Carbon (C) |
0.06-0.18 |
0.30 max (typically around 0.23-0.28 for Grade B) |
| Manganese (Mn) |
0.27-0.63 |
0.29-1.06 (Grade B requirement) |
| Phosphorus (P) |
≤0.035 |
≤0.025 |
| Sulfur (S) |
≤0.035 |
≤0.025 (Grade B) |
| Silicon (Si) |
Not specified in A179 |
0.10 min (often 0.10-0.35 for Grade B) |
Mechanical Properties Comparison Table
| Mechanical Properties |
A179 Seamless Steel Pipe |
A106 Grade B Seamless Steel Pipe |
| Tensile Strength (MPa) |
≥325 (usually in the range of 325-425) |
415 min (Grade B, often higher in practice, up to 585 or more) |
| Yield Strength (MPa) |
≥190 |
240 min (Grade B, typically higher) |
| Elongation (%) |
≥35 (or ≥30 in some standards for specific sizes/conditions) |
Varies with pipe size, but generally ≥30 for longitudinal strip specimens under standard specifications |