SM400 Steel Plate
SM400 structural steel plate for welded structures, delivering reliable strength, weldability, and toughness for construction and fabrication projects.
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Designed for Welding: Manufactured for excellent weldability in welded structures and bridges.
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Good Mechanical Strength: Provides stable yield and tensile performance for structural loads.
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Reliable Toughness: Available grades for improved low-temperature impact resistance.
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Easy Fabrication: Excellent machinability, cutting, bending, and forming performance.
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Cost-Effective: Widely used, economical choice for general structural applications.
SM400 Steel Description
SM400 is a high-quality structural steel grade defined under JIS G3106, specially intended for welded structural applications such as bridges, buildings, ship components, and heavy machinery frames. Available in grades SM400A / SM400B / SM400C, it balances strength, ductility and weldability to meet the needs of fabricators and structural engineers.
SM400 supports reliable welding processes and offers consistent mechanical performance—yield strength around 245 MPa and tensile strength typically 400–510 MPa—making it suitable for load-bearing members and welded assemblies. Choose SM400B or SM400C when improved low-temperature toughness is required.
SM400 Technical Data Sheet
| SM400 Chemical Composition | |
| Element | Max / Range (%) |
| Carbon (C) | ≤ 0.20 |
| Silicon (Si) | ≤ 0.55 |
| Manganese (Mn) | ≤ 1.60 |
| Phosphorus (P) | ≤ 0.035 |
| Sulfur (S) | ≤ 0.035 |
| SM400 Mechanical Properties | |
| Property | Minimum Value / Note |
| Yield Strength (ReL) | ≥ 245 MPa (typical, t ≤ 16 mm) |
| Tensile Strength (Rm) | 400–510 MPa |
| Elongation (A5) | ≥ 21% |
| Impact Energy (Charpy V) | SM400A: not specified / SM400B: 27 J @ 0°C / SM400C: 27 J @ -20°C |
SM400 Applications
SM400 plates are widely used in welded structural engineering and fabrication, including:
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Bridges and overpasses
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Building and civil engineering steelwork
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Shipbuilding and marine structures
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Cranes, frames and heavy machinery supports
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Storage tanks and welded containers
Its good weldability and balanced mechanical properties make SM400 ideal where welded joints and long-term structural integrity are critical.
