ALLLAND Steel Pipe Supply
Welcome to ALLLAND Steel Pipe Manufacturing. ASTM A106 Grade C is a high-strength seamless carbon steel pipe designed for use in demanding high-temperature and high-pressure applications. It is primarily used in industrial sectors such as oil and gas transportation, petrochemical plants, and power generation. ALLLAND manufactures this product in strict accordance with international standards, ensuring excellent structural stability, safety, and reliability even under high-temperature and high-pressure conditions. We offer a wide range of ASTM A106 Grade C sizes and specifications, with stable global supply and fast delivery.
Alllandsteel is a steel pipe manufacturer based in China with 25 years of experience.
The facility spans 22,000 square meters, represents a RMB 700 million investment, and operates four production lines (JCOE, ERW, SMLS, SSAW) alongside five coating lines.
With an annual production capacity of 250,000 tons, the factory covers specifications ranging from Ø406 to Ø1524 and holds multiple international certifications (API/ASTM/EN/ISO/JIS). Focused on steel pipes, creating value for you!
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ASTM A106 Grade C is the highest-strength grade within the ASTM A106 series, established by ASTM International. ASTM A106 is a key standard for seamless carbon steel pipes used in high-temperature applications.
ASTM A106 Grade C is a high-strength seamless carbon steel pipe suitable for high-temperature transmission lines, industrial pressure pipelines, and oil and gas transportation.
O.D.:
10.3 mm – 1219 mm
Size Range:
NPS 1/8″ – 48″
W.T.:
Sch 10 – XXS
1.24 mm – 59.54 mm
Length:
SRL / DRL / Fixed; custom lengths per project requirements.
Manufacturing:
Seamless
Steel Type:
Carbon Steel
Heat Treatment:
Hot Finished / Normalized / Stress Relieved
Coating:
Black Painted / Varnish / 3PE / FBE / Galvanized
| NPS | OD (mm) | Common Schedule |
| 1/8″ | 10.3 | Sch 40 / 80 |
| 1/4″ | 13.7 | Sch 40 / 80 |
| 3/8″ | 17.1 | Sch 40 / 80 |
| 1/2″ | 21.3 | Sch 40 / 80 / 160 |
| 3/4″ | 26.7 | Sch 40 / 80 / 160 |
| 1″ | 33.4 | Sch 40 / 80 / 160 |
| 1-1/4″ | 42.2 | Sch 40 / 80 |
| 1-1/2″ | 48.3 | Sch 40 / 80 |
| 2″ | 60.3 | Sch 40 / 80 / 160 |
| 2-1/2″ | 73.0 | Sch 40 / 80 |
| 3″ | 88.9 | Sch 40 / 80 / 160 |
| 4″ | 114.3 | Sch 40 / 80 / XS |
| 5″ | 141.3 | Sch 40 / 80 |
| 6″ | 168.3 | Sch 20 / 40 / 80 |
| 8″ | 219.1 | Sch 20 / 40 / 80 |
| 10″ | 273.0 | Sch 20 / 40 |
| 14″ | 355.6 | Sch STD |
| 16″ | 406.4 | Sch STD |
| 18″ | 457.0 | Sch STD |
| 20″ | 508.0 | Sch STD |
| 24″ | 609.6 | Sch STD |
| 30″ | 762.0 | Custom WT |
| 36″ | 914.0 | Custom WT |
| 42″ | 1067.0 | Custom WT |
| 48″ | 1219.0 | Custom WT |
Large-diameter ASTM A106 Grade C steel pipes are difficult to manufacture and are typically produced on a custom basis.
OD Tolerance:
NPS ≤ 2″: ±0.4 mm
NPS > 2″: ±1%
WT Tolerance: −12.5% / +No Upper Limit Specified
Length Specification：
| Type | Length |
| SRL | Approx. 5.8–6 m |
| DRL | Approx. 11.8 – 12 m |
| Fixed Length | Cut-to-length |
| Element | Grade C |
| Carbon (C) | ≤ 0.35% |
| Manganese (Mn) | 0.29 – 1.06% |
| Phosphorus (P) | ≤ 0.035% |
| Sulfur (S) | ≤ 0.035% |
| Silicon (Si) | ≥ 0.10% |
Based on its chemical composition, ASTM A106 Grade C is essentially a high-strength, medium-carbon seamless steel pipe.
Grade C has a higher carbon content than Grade B: Grade B: ≤0.30%, Grade C: ≤0.35%. While strength and hardness are increased, weldability and ductility are reduced.
| Property | Grade C |
| Tensile Strength | ≥ 485 MPa |
| Yield Strength | ≥ 275 MPa |
Compared to Grade B
| Property | Grade B | Grade C |
| Tensile Strength | ≥ 415 MPa | ≥ 485 MPa |
| Yield Strength | ≥ 240 MPa | ≥ 275 MPa |
As can be seen, Grade C has higher tensile strength and yield strength, making it suitable for applications that require higher pressures and loads.
The elongation of ASTM A106 Grade C varies with thickness and is generally slightly lower than that of Grade B, typically ranging from ~20% to 30%.
ASTM A106 Grade C is the highest strength grade in the ASTM A106 standard and is specifically designed for piping used in high-temperature, high-pressure applications.
Compared to Grade C, it offers higher mechanical strength but is less commonly used in the market; it is typically reserved for applications with extremely stringent requirements for strength, pressure, and temperature, or for special operating conditions.
High-temperature, high-pressure steam transport pipelines, boiler systems, and feedwater systems
High-pressure process pipelines, furnace tubes, and heat exchanger connecting pipes
Industrial piping systems for high-temperature, high-pressure fluids such as water, oil, and gas
Offshore engineering, marine propulsion, and high-pressure piping systems
| Application | Grade B | Grade C |
| General industrial applications | ✔ | ✔ |
| Petrochemical main lines | ✔ | ✔(Higher pressure applications are preferred) |
| Power plant steam | ✔ | ✔✔(Grade C is more recommended) |
| High-pressure extreme conditions | △ | ✔ |
No.
ASTM A106 Grade C applies only to: Seamless Carbon Steel Pipe
Grade C has higher mechanical strength, but its weldability is lower than that of Grade B. It is rarely used in general projects and is primarily intended for more demanding applications with stricter requirements.
Generally, yes.
This is because Grade C has higher strength. However, factors such as cost, welding processes, and project specifications must be taken into account.
