A387 Grade 11 Class 1 boiler steel plates are chromium-molybdenum alloy steel plates designed for high-temperature and high-pressure service conditions.
As a professional steel plate manufacturer and global exporter, GNEE Steel supplies ASTM A387 Grade 11 Class 1 plates strictly in accordance with ASTM standards, ensuring stable quality for pressure vessel and boiler applications.
A387 Grade 11 Class 1 boiler steel plates
Within the first 100 words, it is essential to clarify that GNEE is a manufacturer-focused supplier, not a temporary stock trader. Our A387 Gr11 Cl1 steel plates are produced under controlled rolling and heat treatment processes and are typically supplied in Normalized and Tempered (N+T) condition to guarantee consistent mechanical performance.
With over ten years of experience, we support EPC contractors, fabricators, and end users across oil & gas, petrochemical, refinery, and power generation industries.
Chemical Composition of A387 Grade 11 Class 1 Boiler Steel Plates
The chemical composition of A387 Grade 11 Class 1 steel is carefully balanced to achieve oxidation resistance, corrosion resistance, and excellent weldability under elevated temperatures.
Chemical Composition Table (%)
| Grade | C | Mn | Si | P max | S max |
|---|---|---|---|---|---|
| A387 Grade 11 Class 1 | 0.04–0.17 | 0.35–0.73 | 0.44–0.86 | 0.035 | 0.035 |
Mechanical Properties of A387 Grade 11 Class 1 Steel Plate
A387 Grade 11 Class 1 boiler steel plates are engineered to withstand long-term exposure to pressure and heat without performance degradation.
Mechanical Property Table
| Property | Value |
|---|---|
| Tensile Strength | 415–580 MPa |
| Yield Strength (min) | 240 MPa |
| Elongation (50mm) | ≥22% |
| Impact Test Temperature | -20 / -40 / -60 °C |
A387 Grade 11 Class 1 Steel Plate Specifications & Sizes
GNEE supplies A387 Grade 11 Class 1 steel plates in a wide range of sizes to meet different fabrication needs.
- Specification details:
- Standard: ASTM A387
- Grade: A387 Grade 11 Class 1 / A387 GR11 CL1
- Thickness: 3.0 mm – 150 mm
- Shapes: Plates, sheets, coils
- Finish: Hot Rolled (HR), Cold Rolled (CR)
- Processing services available:
- Cutting and profiling
- Drilling and machining
- Welding and grinding
- Milling and surface testing
Applications of A387 Grade 11 Class 1 Boiler Steel Plates
Thanks to their chromium-molybdenum alloy composition, A387 Grade 11 Class 1 plates are widely used in demanding industrial environments.
Typical applications include:
Boilers and boiler drums
Pressure vessels and reactors
Heat exchangers and condensers
Oil & gas storage tanks
Sour gas and petrochemical equipment
These plates offer excellent resistance to oxidation, pitting corrosion, crevice corrosion, and stress corrosion cracking.
Inspection & Quality Control for A387 Grade 11 Class 1 Plates
To guarantee consistent quality, GNEE supports comprehensive inspection throughout the production and delivery process.
Available inspection options:
Ultrasonic Testing (UT)
Charpy V-Notch Impact Test
Third-party inspection (SGS, BV, Lloyd's)
Z-direction testing (Z15 / Z25 / Z35)
Each shipment is supplied with full inspection documentation to ensure compliance with project specifications and international standards.
Equivalent Grades of A387 Grade 11 Class 1 Steel Plate
A387 Grade 11 Class 1 steel plate is equivalent to several international standards, making it suitable for global projects:
BS: 622-515B
EN: 10CrMo9-10
DIN: 10CrMo9-10
As a reliable manufacturer and exporter, GNEE Steel supplies A387 Grade 11 Class 1 boiler steel plates with stable chemistry, proven mechanical performance, and strict quality control. Our plates are trusted by clients in more than 45 countries, including Saudi Arabia, UAE, Singapore, Malaysia, and beyond.
Contact us for the latest A387 Grade 11 Class 1 boiler steel plates price list, stock availability, and technical support.
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What is ASTM A387 material?
ASTM A387 GR. 91 CL. 2 Alloy Steel Plates manufactured at the world's finest steel mills, this molybdenum-chrome based alloy has excellent resistance to greater working temperatures, making it the right selection for various applications like in gas, oil, chemical, and power generation.
What is ASTM A387 Grade 11 equivalent to?
ASTM A387 grade 11 equivalent steel is ASME SA387 grade 11. ASTM A387 grade 11 covers A387 grade 11 class 1 and A387 grade 11 class 2, which are equivalent to ASME SA387 grade 11 class 1 and SA387 grade 11 class 2 respectively.
What is the difference between ASTM A182 and A387?
A387 is Plate material. A182 is Forging material. You can refer relevant ASTM Book of standards.
What is ASTM A387?
The ASTM A387 specification is the Standard Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum plates used in the application of welded boilers and pressure vessels subjected to elevated temperatures. The two grades SSAB produces are available as Class 1 and/or Class 2.