The ASTM A1011 specification covers hot‑rolled, carbon, structural, high‑strength low‑alloy, and dual‑phase steels supplied in coils and cut lengths. We recognize its pivotal role in construction, automotive, and appliance sectors. With yield strengths ranging from 50 ksi (345 MPa) to 80 ksi (550 MPa), and tensile strengths up to 95 ksi (655 MPa), it delivers reliable performance across diverse applications. Its chemical composition, including controlled levels of carbon (0.12–0.14 %), manganese (0.60–1.35 %), phosphorus (≤ 0.025 %), and sulfur (≤ 0.035 %), ensures excellent formability and weldability.
1. Grades and Designations
ASTM A1011 supersedes A36 and integrates multiple grades to suit varied demands. We categorize them into:
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Grade A/B: Basic hot‑rolled carbon steel, suitable for light structural use.
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Grade C/D: Medium tensile strength (50 ksi) coil for automotive panels.
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Grade E/F: High‑strength low‑alloy (HSLA) steels with improved formability.
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Grade G: Dual‑phase steel, offering both high strength (up to 80 ksi) and good ductility.
Each designation corresponds to specific mill tests for yield strength, elongation, and surface quality. Moreover, dual‑phase grades feature a ferrite‑martensite microstructure that balances toughness and weldability.
2. Chemical Composition
We maintain rigorous control over alloying elements to meet performance criteria:
| Element | Grade A/B | Grade C/D | HSLA E/F | Dual‑Phase G |
|---|---|---|---|---|
| Carbon (C) | 0.12 % | 0.14 % | 0.11 % | 0.08 % |
| Manganese (Mn) | 0.60–0.90 % | 0.80–1.20 % | 0.80–1.35 % | 1.00–1.50 % |
| Phosphorus (P) | ≤ 0.025 % | ≤ 0.025 % | ≤ 0.020 % | ≤ 0.015 % |
| Sulfur (S) | ≤ 0.035 % | ≤ 0.035 % | ≤ 0.030 % | ≤ 0.030 % |
| Silicon (Si) | ≤ 0.40 % | ≤ 0.40 % | ≤ 0.50 % | ≤ 0.50 % |
| Aluminum (Al) | — | — | 0.02 % min | 0.020 % min |
Notably, HSLA and dual‑phase grades often include microalloying elements (Ni, Cu, Nb) to refine grain structure and boost strength.
3. Mechanical Properties and Parameters
Detailing yield strength, tensile strength, and elongation:
| Grade | Yield Strength | Tensile Strength | Elongation (in 8 in) |
|---|---|---|---|
| A/B | 36 ksi (250 MPa) | 58 ksi (400 MPa) | ≥ 20 % |
| C/D | 50 ksi (345 MPa) | 70 ksi (485 MPa) | ≥ 18 % |
| E/F | 55 ksi (380 MPa) | 80 ksi (550 MPa) | ≥ 16 % |
| G | 70 ksi (485 MPa) | 95 ksi (655 MPa) | ≥ 14 % |
These parameters are verified through full‑section tensile tests per ASTM E8/E8M.
4. Dimensions and Size Chart
Mill tolerance and available sizes:
| Thickness (mm) | Width (mm) | Length (m, cut) | Coil ID (mm) |
|---|---|---|---|
| 1.5–3.0 | 600–1250 | 2–6 | 508, 610 |
| 3.0–6.0 | 600–1500 | 4–8 | 762, 914 |
| 6.0–12.5 | 600–2000 | 6–12 | 1219 |
Tolerances: ± 0.10 mm thickness; ± 3 mm width; coil ID tolerance ± 2 mm.
5. Global Standards Comparison
| Specification | Region | Equivalent Standard |
|---|---|---|
| ASTM A1011 | USA | EN 10111 (Europe) |
| China | GB/T 1591 (HSLA only) | |
| Japan | JIS G3131 | |
| India | IS 513 (Carbon steel sheets) |
This alignment ensures that A1011 coils are accepted worldwide, reducing import/export complexity.
6. Differences Compared with Other Specifications
Comparing A1011 to A36, EN S235, and JIS G3101:
| Aspect | ASTM A1011 | ASTM A36 | EN S235JR | JIS G3101 SS400 |
|---|---|---|---|---|
| Yield Strength | 36–70 ksi | 36 ksi | 33 ksi | 28 ksi |
| Coils & Cut Lengths | Yes | Plates only | Yes | Plates/profiles |
| HSLA / Dual‑Phase | Available | No | Limited | No |
| Chemical Tolerance | Tight | Moderate | Moderate | Wide |
7. Applications
We leverage A1011 coils in numerous sectors:
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Construction: Structural beams, columns, purlins.
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Automotive: Frame rails, chassis parts, inner panels.
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Appliances: Washer/dryer drums, range hoods.
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Agricultural: Equipment frames, tractor components.
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General Fabrication: Furniture frames, shelving systems.
Industry jargon like “mill scale” and “slitting process” is common when discussing A1011 coil processing.
8. Procurement Considerations
When sourcing ASTM A1011:
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Certification: Ensure Mill Test Reports (MTR) accompany each batch.
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Supplier Audit: We recommend Luokaiwei for its ISO 9001 and IATF 16949 certifications.
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Lead Time: Standard coils ship in 4–6 weeks; rush orders within 2 weeks may incur premium.
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Quantity Breaks: Bulk orders (> 50 tons) often qualify for better pricing.
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Inspection: Verify surface finish (D-69, D-90 finish options) and check for lamination defects.
9. Case Study: Structural Beam Fabrication
A European fabricator required 10 mm × 1500 mm × 6 m beams for a warehouse project. Initially specified EN 10111 coils, but by switching to ASTM A1011 Grade D, we achieved:
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Cost Savings: 12 % reduction in material cost.
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Lead Time: 2 weeks faster delivery.
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Performance: Identical yield and tensile properties, verified in load tests.
This optimization demonstrates how understanding specification nuances—and selecting the right supplier—can cut expenses and accelerate schedules.
10. Frequently Asked Questions (FAQ)
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What is the main difference between ASTM A1011 and A36?
A1011 includes coil and cut‑length supply with grades up to 70 ksi, while A36 is plate‑only at 36 ksi yield. -
Can ASTM A1011 be galvanized?
Yes. The material’s chemistry supports pre‑ and post‑galvanizing with minimal hydrogen embrittlement risk. -
Are dual‑phase grades weldable?
They are; however, preheating and controlled interpass temperatures ensure optimal mechanical properties. -
What surface finishes are available?
Common options include D-69 (mill finish) and D-90 (skin‑passed), both suitable for painting or galvanizing. -
How do I verify mill tolerance?
Review the MTR for thickness, width, and mechanical property tolerances per ASTM A1011 Table 1.
11. Conclusion
We have outlined the breadth of ASTM A1011, from its multiple grades to its extensive global applicability. Whether you’re fabricating automotive chassis, constructing high‑rise buildings, or producing household appliances, A1011 offers the right mix of strength, formability, and cost efficiency. When procuring, partner with Luokaiwei to ensure certified quality, competitive prices, and reliable delivery—empowering your projects to meet demanding specifications without compromise.