Carbon Steel Angle Steel for Bridge Construction S235jr S275jr A572 Gr50 Gr60 A36 Ss400 Mild Steel Angle Bar

Material Grade Specifications & Bridge-Specific Performance​

Each grade is selected for its unique mechanical properties, optimized to address the varied stress, environmental, and load conditions of bridge projects:​

S235jr (EN 10025-2): A European standard mild steel grade with a minimum yield strength of 235 MPa and tensile strength of 360-510 MPa. It offers excellent weldability, ductility (elongation ≥26%), and cost-effectiveness, making it ideal for non-critical bridge components such as secondary bracings, handrail supports, and lightweight frame elements. Its room-temperature impact resistance (≥27 J at 20°C) ensures safety under dynamic loads from traffic.​

S275jr (EN 10025-2): With a minimum yield strength of 275 MPa and tensile strength of 370-530 MPa, this grade delivers enhanced load-bearing capacity compared to S235jr. It maintains superior weldability and toughness, suitable for primary bridge components like floor beam connections, cross-bracings, and approach span frames-where moderate stress resistance is required.​

A572 Gr50 (ASTM A572): A high-strength low-alloy (HSLA) steel grade with a minimum yield strength of 345 MPa and tensile strength of 450-550 MPa. It exhibits exceptional fatigue resistance and corrosion resistance (due to copper addition), making it a top choice for heavy-duty bridge components: main truss members, stringers, and load-bearing columns in long-span or high-traffic bridges. Its low carbon content ensures compatibility with high-strength welding processes.​

A572 Gr60 (ASTM A572): Offering a minimum yield strength of 414 MPa and tensile strength of 515-655 MPa, this grade provides maximum load capacity for critical bridge structures. It is used in ultra-long-span bridges, cable-stayed bridge towers, and seismic-resistant bridge frames-where high stress, vibration, and environmental extremes demand superior structural performance.​

A36 (ASTM A36): A versatile mild steel grade with a minimum yield strength of 250 MPa and tensile strength of 400-550 MPa. Equivalent to SS400 and S235jr, it is cost-effective for general bridge components: guardrail posts, drainage brackets, and auxiliary frame elements. Its excellent formability allows for custom bending to fit complex bridge geometries.​

SS400 (JIS G 3101): A Japanese standard mild steel grade with mechanical properties matching A36 (minimum yield strength 235 MPa, tensile strength 400-510 MPa). It is widely used in cross-border bridge projects, offering consistent quality, weldability, and compatibility with international fabrication standards-serving as a reliable alternative for A36 or S235jr in global supply chains.​

Structural Advantages for Bridge Applications​

The L-shaped design of these angle bars provides unique benefits tailored to bridge engineering needs:​

Load Distribution Efficiency: Equal or unequal leg configurations enable balanced transfer of axial, bending, and shear forces-critical for bridge components that bear dynamic loads (e.g., traffic, wind, seismic activity). Unequal legs (e.g., 100x63mm) are particularly useful for connecting dissimilar structural members (e.g., wide beams to narrow columns) without material waste.​

Structural Rigidity: The angular cross-section enhances torsional stiffness, reducing deflection in bridge frames and bracings under heavy loads. This minimizes long-term structural deformation, ensuring bridge safety and extending service life.​

Easy Integration: Flat leg surfaces allow for secure welding, bolting, or riveting to other bridge components (e.g., I-beams, channels, plates). This simplifies on-site assembly, reducing construction time and labor costs-essential for large-scale bridge projects with tight timelines.​

Manufacturing & Quality Control for Bridge Standards​

To meet the stringent requirements of bridge construction, our angle bars undergo specialized production and testing:​

Hot-Rolling Process: Steel billets are heated to 1100-1250°C (above recrystallization temperature) and rolled into precise L-shaped profiles. This process eliminates internal defects, refines grain structure, and ensures uniform mechanical properties-critical for withstanding cyclic bridge loads.​

Bridge-Specific Testing: Each batch undergoes rigorous quality checks beyond standard industrial protocols:​

Fatigue Testing: Simulates millions of load cycles to verify resistance to long-term wear (essential for high-traffic bridges).​

Corrosion Resistance Testing: Salt spray tests or atmospheric exposure tests (for A572 grades) to ensure durability in outdoor, humid, or coastal bridge environments.​

Ultrasonic Flaw Detection: Identifies internal cracks or inclusions that could compromise structural safety in critical bridge components.​

Compliance with Bridge Codes: All grades meet international bridge design standards, including AASHTO LRFD (American Association of State Highway and Transportation Officials Load and Resistance Factor Design), Eurocode 3 (European Committee for Standardization), and JIS A 5525 (Japanese Industrial Standard for Bridge Steel)-ensuring seamless integration into global bridge projects.​

Application Scope in Bridge Construction​

These carbon steel angle bars are integral to all stages and types of bridge projects:​

Beam Bridges: Used as cross-bracings between floor beams, connection brackets for stringers, and handrail supports.​

Truss Bridges: Serve as diagonal truss members (A572 Gr50/Gr60 for main trusses; S275jr for secondary trusses) and node connections, distributing loads across the truss framework.​

Cable-Stayed Bridges: Utilized in tower bracings, deck edge frames, and cable anchor brackets-with A572 Gr60 providing high strength for tower structures.​

Seismic-Resistant Bridges: A572 Gr50/Gr60 grades, with their superior toughness, are used in energy-dissipating bracings and flexible frame connections to mitigate earthquake damage.​

Coastal Bridges: A572 Gr50 (with copper alloying) resists saltwater corrosion, making it suitable for pier columns, pile caps, and coastal approach spans.​

Quality Assurance & Certification​

To guarantee reliability for bridge projects-where structural failure has severe consequences-we implement strict quality management:​

ISO Certifications: Production facilities are ISO 9001 (quality management) and ISO 14001 (environmental management) certified, ensuring consistent manufacturing and sustainable practices.​

Material Traceability: Each angle bar is marked with grade, batch number, and production date, allowing full traceability from raw material (steel billets) to final delivery.​

Third-Party Inspection: Critical batches (e.g., A572 Gr60 for main bridge members) undergo independent testing by accredited laboratories (e.g., SGS, BV) to verify compliance with ASTM/EN/JIS standards.​

Certification Documentation: Every shipment includes a Mill Test Certificate (MTC) with detailed mechanical properties, chemical composition, and test results-required for bridge project approval by engineering firms and regulatory bodies.​

Our carbon steel angle bars for bridge construction combine grade-specific performance, structural efficiency, and rigorous quality control-providing engineers, contractors, and infrastructure developers with a trusted solution for building safe, durable, and long-lasting bridges worldwide.​