ASTM A106 Carbon Steel Pipe: Grades, Specs & Applications
ASTM A106 is the most widely specified standard for seamless carbon steel pipe in high-temperature service. If your project calls for boiler piping, refinery lines or power plant steam service, this is the standard your engineers will reference first. Here is what you need to know before you order.
What Is ASTM A106?
ASTM A106 (full title: Standard Specification for Seamless Carbon Steel Pipe for High-Temperature Service) covers seamless carbon steel pipe intended for use at elevated temperatures. It is manufactured from killed carbon steel and is produced in three grades: A, B and C.
Because it is seamless, A106 pipe has no weld seam, which makes it the default choice for pressure-containing systems where a weld could be the weakest point.
Grades A, B and C — Key Differences
| Grade | Yield Strength (min) | Tensile Strength (min) | Typical Use |
|---|---|---|---|
| A | 205 MPa (30 ksi) | 415 MPa (60 ksi) | Low-pressure, low-cost service |
| B | 240 MPa (35 ksi) | 415 MPa (60 ksi) | Most common grade, general pressure service |
| C | 275 MPa (40 ksi) | 485 MPa (70 ksi) | Higher-pressure and heavy-wall applications |
Grade B is by far the most common in export orders. Grade C is specified when higher strength is required without moving to an alloy grade.
Chemical Composition
The main elements are carbon, manganese, phosphorus, sulfur and silicon. For Grade B, typical limits are:
- Carbon: max 0.30%
- Manganese: 0.29–1.06%
- Phosphorus: max 0.035%
- Sulfur: max 0.035%
- Silicon: min 0.10%
Silicon is added as a deoxidizer (the pipe is fully killed), which improves high-temperature stability.
Temperature Limits
A106 pipe is designed for high-temperature service, but it is a carbon grade, not a creep-resistant alloy. Practical guidance:
- Normal operating range: up to about 425 °C (800 °F) for continuous service
- Above 425 °C, consider alloy grades such as A335 P11, P22 or P91
- At low temperatures, impact testing or a low-temperature grade (such as A333) is usually required
Surface Finish, Ends and Testing
Standard supply options include plain end, beveled end (for welding) and threaded & coupled. Common supplementary requirements include:
- Hydrostatic testing (standard requirement)
- Nondestructive electric testing (ET or UT)
- Ultrasonic inspection per supplementary requirement S1 or S2
- Impact testing for low-temperature service
Always confirm which supplementary requirements your project specification demands, because they affect both price and lead time.
ASTM A106 vs. ASTM A53
A53 is a similar carbon steel pipe standard but covers both seamless and welded pipe, and it is generally considered a “utility grade.” A106 has stricter requirements and is preferred for high-temperature and pressure service. When in doubt, specify A106 Grade B for pressure applications.
How to Order ASTM A106 Pipe
When requesting a quote, provide:
- Standard and grade (e.g. ASTM A106 Grade B)
- Outside diameter and wall thickness (or schedule number)
- Length (SR/DR — single/double random, or fixed)
- End type (plain, beveled or threaded)
- Supplementary testing requirements
- Certificate requirements (EN 10204 3.1/3.2) and third-party inspection (SGS, BV, TUV)
If you are sourcing A106 pipe for a boiler, refinery or power project, send our engineers your pressure, temperature and specification sheet. We will confirm grade, sizes and testing within 24 hours.
