Both ASTM A387 Grade 11 Class 1 and SA387 Grade 11 Class 1 are chromium-molybdenum alloy steel plates used for pressure vessels and boilers designed for elevated temperature service.
While they share similar chemical compositions and mechanical properties, there are subtle differences in standards, applications, and inspection requirements.
Overview of ASTM A387 Grade 11 Class 1 and SA387 Grade 11 Class 1
| Feature | ASTM A387 Grade 11 Class 1 | SA387 Grade 11 Class 1 |
|---|---|---|
| Standard | ASTM A387 / ASME | ASME SA-387 |
| Material Type | Chromium-molybdenum alloy steel | Chromium-molybdenum alloy steel |
| Application | Welded boilers, pressure vessels, high-temperature service | Welded boilers, pressure vessels, high-temperature service |
| Heat Treatment | Normalized and Tempered | Normalized and Tempered |
| Global Use | Widely used internationally, especially US, Europe, Middle East | Primarily used in ASME code applications, North America |
Chemical Composition of ASTM A387 Grade 11 Class 1 and SA387 Grade 11 Class 1
| Element | ASTM A387 Grade 11 Class 1 (%) | SA387 Grade 11 Class 1 (%) |
|---|---|---|
| Carbon (C) | 0.05 – 0.17 | 0.05 – 0.17 |
| Manganese (Mn) | 0.40 – 0.65 | 0.40 – 0.65 |
| Phosphorus (P) | ≤ 0.035 | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 | ≤ 0.035 |
| Silicon (Si) | 0.50 – 0.80 | 0.50 – 0.80 |
| Chromium (Cr) | 1.00 – 1.50 | 1.00 – 1.50 |
| Molybdenum (Mo) | 0.45 – 0.65 | 0.45 – 0.65 |
Both steel grades have almost identical chemical compositions, ensuring similar strength, corrosion resistance, and heat-resistance properties.
Mechanical Properties of ASTM A387 Grade 11 Class 1 and SA387 Grade 11 Class 1
| Property | ASTM A387 Grade 11 Class 1 | SA387 Grade 11 Class 1 |
|---|---|---|
| Yield Strength (MPa) | ≥ 240 | ≥ 240 |
| Tensile Strength (MPa) | 415 – 585 | 415 – 585 |
| Elongation % | 19 – 22 | 19 – 22 |
| Impact Toughness (Optional) | Can meet Charpy V-notch requirements | Can meet Charpy V-notch requirements |
Mechanical performance is essentially the same, making both suitable for high-temperature pressure vessels and boilers.
Heat Treatment and Process Performance
| Feature | ASTM A387 Grade 11 Class 1 | SA387 Grade 11 Class 1 |
|---|---|---|
| Heat Treatment | Normalized and Tempered | Normalized and Tempered |
| Cold Forming & Welding | Excellent | Excellent |
| Surface Finish | Hot rolled / cold rolled | Hot rolled / cold rolled |
| Inspection | Third-party testing (mill certificate, chemical & mechanical) | ASME code compliance testing |
Both grades support welding, stamping, and forming. SA387 may have additional ASME-specific documentation requirements.
Applications of ASTM A387 Grade 11 Class 1 and SA387 Grade 11 Class 1
ASTM A387 Grade 11 Class 1:
- Welded boilers
- Pressure vessels in chemical, petrochemical, and oil industries
- High-temperature piping components
SA387 Grade 11 Class 1:
- ASME code pressure vessels and boilers
- Industrial heat exchangers
- High-temperature gas and steam storage equipment
While the applications overlap significantly, SA387 is more aligned with ASME-certified equipment, whereas ASTM A387 is widely accepted globally for general high-temperature pressure vessel applications.
| Aspect | ASTM A387 Grade 11 Class 1 | SA387 Grade 11 Class 1 |
|---|---|---|
| Standards | ASTM / ASME | ASME SA-387 |
| Chemical Composition | Same | Same |
| Mechanical Properties | Same | Same |
| Heat Resistance | Same | Same |
| Typical Use | International industrial vessels | ASME pressure vessels, boilers |
| Documentation | Mill Test Certificate | ASME Code documentation |
Choose ASTM A387 Grade 11 Class 1 if your project requires global standard compliance and flexibility for international applications.
Choose SA387 Grade 11 Class 1 if your project specifically follows ASME code-certified pressure vessel standards, particularly in North America or when ASME certification is mandatory.
If you are sourcing ASTM A387 Grade 11 steel plates, provide your required specifications such as thickness, width, quantity, and application. A detailed quotation and technical support can be arranged to meet your project requirements.
Contact now to get A387 Steel Plate Quote
What is a A387 steel equivalent to?
Other designations that are equivalent to AISI A387 grade 22-PVQ alloy steel include the following: ASTM A182 (F22-1) ASTM A199 (T22)
What is A387 grade 22 material?
ASTM A387 Grade 22 (ASME SA387 Grade 22) is Chrom-Moly steel plate used for making boilers and pressure vessles designed for high temperature high pressure serivce, chrome content at 2.00% to 2.50%, and Moly 0.90% to 1.10% for SA387 GRADE 22 material.
What is the chemical composition of ASTM A387 Grade 12?
ASTM A387 GR 12 CL 2 Plates is designed with chemical components such as silicon, chromium, vanadium, molybdenum, sulfur, phosphorus, carbon, and manganese. Alloy Gr 12 has some tensile requirements, such as tensile strength, area reduction, elongation, and yield strength.
What is the difference between ASTM A182 and A387?
Both ASTM A182 grade F11 class 2 and ASTM A387 grade 22 steel are iron alloys. They have a very high 99% of their average alloy composition in common. There are 32 material properties with values for both materials. Properties with values for just one material (1, in this case) are not shown.