On December 12, 2024, we received an inquiry from an old customer in Vietnam, requiring a batch of ASTM A333 Grade 6 steel pipes. We have cooperated with this customer many times before.
After receiving the quotation, the customer was very interested in the price and delivery time, and asked if we had produced similar products before. We provided the customer with product pictures and packaging pictures of previous orders, and the customer was very satisfied.
One month later, we received a purchase order from the customer. The list is as follows:
| NO | Description | Material |
| 1 | PIPE Ø168.3*10.97 L=0.25M | SA-333 GR.6 |
| 2 | PIPE Ø219.1*12.7 L=0.35M | SA-333 GR.6 |
| 3 | PIPE Ø273*12.7 L=0.2M | SA-333 GR.6 |
| 4 | PIPE Ø356*19.05 L=0.5M | SA-333 GR.6 |
| 5 | PIPE Ø406.4*12.7 L=0.5M | SA-333 GR.6 |
| 6 | PIPE Ø406.4*9.53 L=1M | SA-333 GR.6 |
| 7 | PIPE Ø88.9*15.2 L=3.3M | SA-333 GR.6 |
ASTM A333 Grade 6 (A333 Gr.6) is a seamless and welded carbon steel pipe designed for low-temperature applications, ensuring high impact toughness. It is widely used in industries such as oil & gas, petrochemical, power plants, and refineries.
Manufacturing Process:
Available in Seamless & Welded types
Heat Treatment: Normalized, Quenched & Tempered (if required)
Hydrostatic Testing & Non-Destructive Testing (NDT) performed
ASTM A333 Grade 6 Pipe Specification
| Processing Method | Seamless and Welded |
| Size Range | 1/8″- 48″ / DN6 – 1200 |
| Thickness Schedule | SCH 10, SCH 20, SCH 40, STD, XS, SCH 100, SCH 120, SCH 160, XXS |
| Length | 6m or 12 m or Random |
| Standard | ASME B36.10M |
| Surface Treatment | Blasting and Painting , Epoxy Powder FBE, 2PE, 3PE Coating |
| Material Grade | ASTM A106B / A53, API 5L B / X42 / 46 / 52 / 56 / 60 / 65 / 70, A333 GR 6 |
Equivalent Grades Of Grade 6 ASTM A333 Pipe
| Former | New | |||
| Execution | Standard | Material | Standard | Material |
| Seamless | ASTM A333 | GRADE 6 | EN 10216-4 | P265NL |
| DIN | EN | BS | NFA | ASTM | ASME |
| DIN 17178 Grade FGP 28 | EN P265NL Grade 10216-4 | NFA A 36-2051) Grade A 42 AP | ASTM A333 Grade6 | ASME SA 333 Grade 6 | UNI C20 |
ASTM A333 Grade 6 Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Cu | Ni | Cr | Mo | V | Nb |
| ASTM A333 GR 6 | MIN | 0.29 | 0.10 | |||||||||
| MAX | 0.30 | 1.06 | 0.025 | 0.025 | 0.40 | 0.40 | 0.30 | 0.12 | 0.08 | 0.02 |
ASTM A333 Grade 6 Mechanical Property
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % |
| ASTM A333 GR 6 | 415 min | 240 min | 30 min |
Carbon Steel Pipe Thickness Schedule
| DN | NPS | OD | SCH20 | SCH30 | STD | SCH40 | SCH60 | XS | 80 |
| 6 | 1/8 | 10.3 | – | 1.45 | 1.73 | 1.73 | – | 2.41 | 2.41 |
| 8 | 1/4 | 13.7 | – | 1.85 | 2.24 | 2.24 | – | 3.02 | 3.02 |
| 10 | 3/8 | 17.1 | – | 1.85 | 2.31 | 2.31 | – | 3.20 | 3.20 |
| 15 | 1/2 | 21.3 | – | 2.41 | 2.77 | 2.77 | – | 3.73 | 3.73 |
| 20 | 3/4 | 26.7 | – | 2.41 | 2.87 | 2.87 | – | 3.91 | 3.91 |
| 25 | 1 | 33.4 | – | 2.90 | 3.38 | 3.38 | – | 4.55 | 4.55 |
| 32 | 11/4 | 42.2 | – | 2.97 | 3.56 | 3.56 | – | 4.85 | 4.85 |
| 40 | 11/2 | 48.3 | – | 3.18 | 3.68 | 3.68 | – | 5.08 | 5.08 |
| 50 | 2 | 60.3 | – | 3.18 | 3.91 | 3.91 | – | 5.54 | 5.54 |
| 65 | 21/2 | 73.0 | – | 4.78 | 5.16 | 5.16 | – | 7.01 | 7.01 |
| 80 | 3 | 88.9 | – | 4.78 | 5.49 | 5.49 | – | 7.62 | 7.62 |
| 90 | 31/2 | 101.6 | – | 4.78 | 5.74 | 5.74 | – | 8.08 | 8.08 |
| 100 | 4 | 114.3 | – | 4.78 | 6.02 | 6.02 | – | 8.56 | 8.56 |
How to inspect ASTM A333 Grade 6 pipes
1. Visual & Dimensional Inspection
Surface defects: Checked for cracks, seams, and other imperfections.
Dimensions: Outer diameter (OD), wall thickness, and length are measured per ASME B36.10M/B36.19M.
2. Chemical Composition Analysis
Performed using spectro analysis or wet chemical methods to verify compliance with ASTM A333 Grade 6 chemical composition requirements.
3. Mechanical Testing
✔ Tensile Test: Ensures minimum tensile strength (415 MPa) and yield strength (240 MPa).
✔ Hardness Test: Measures material hardness to ensure uniformity.
✔ Impact (Charpy V-Notch) Test: Conducted at -45°C (-50°F) to ensure toughness in low-temperature environments.
Key Features & Benefits:
✅ High toughness at low temperatures (-45°C / -50°F)
✅ Good weldability and machinability
✅ Suitable for pressure vessel & piping applications
✅ Complies with ASME B31.3, ASME B31.1, and API 5L standards
Common Applications:
Cryogenic & Low-Temperature Services
Oil & Gas Pipelines
Chemical & Petrochemical Processing
Power Plants & Refineries
Pressure Vessel Piping