Hot Rolled Steel Building Material Black Metal A36 Ss400 Q235B S235jr Unequal Bar Angle Bar

Hot Rolled Steel Building Material Black Metal A36 Ss400 Q235B S235jr Unequal Bar Angle Bar is a high-performance structural steel product specifically designed for building and construction applications, characterized by its unequal L-shaped cross-section-featuring two legs of different lengths with uniform thickness, and a natural black metal surface formed during the hot-rolling process. Engineered to comply with international and national standards, this unequal angle bar integrates four premium-grade steel materials, delivering exceptional structural stability, load-bearing capacity, and workability, making it an indispensable building material for diverse construction and industrial scenarios.

As a core building material, this unequal angle bar is crafted from four high-quality black metal grades, each with strictly controlled chemical compositions and mechanical properties to adapt to different project requirements and regional standard specifications. Q235B, a Chinese national standard (GB/T 700) carbon structural steel, is an upgraded version of Q235 with a "B" grade indicating notch impact resistance at 20°C. It has a carbon content of 0.12%-0.20%, supplemented by manganese (0.30%-0.70%) and silicon, offering a minimum yield strength of 235 MPa and tensile strength of 370-500 MPa, ensuring reliable basic load-bearing performance and cost-effectiveness for general building structures.

ASTM A36, an American standard (ASTM A36/A36M) carbon structural steel, is widely recognized globally for its excellent ductility and weldability. With a minimum yield strength of 250 MPa and tensile strength of 400-550 MPa, its chemical composition (carbon ≤0.25%, manganese 0.80%-1.20%) ensures superior formability, allowing for easy cutting, bending, and welding without compromising structural integrity. It is extensively used in North American and global building projects that adhere to ASTM standards.

S235JR is a European standard (EN 10025-2) non-alloy structural steel, comparable to Q235B and ASTM A36 in performance. It features a minimum yield strength of 235 MPa (at room temperature) and tensile strength of 360-510 MPa, with the "JR" grade guaranteeing notch impact resistance at 20°C. Its strictly controlled chemical composition (carbon ≤0.17%, manganese 0.30%-0.60%) ensures stable mechanical properties, making it ideal for building projects in the European market and global projects following EN specifications.

SS400 is a Japanese industrial standard (JIS G 3101) carbon structural steel, renowned for its high strength and durability. With a minimum yield strength of 245 MPa and tensile strength of 400-510 MPa, it has a carbon content of 0.17%-0.23% and manganese content of 0.60%-1.00%, providing excellent toughness and workability. This grade is widely used in Japanese and Asian building projects, complementing the other three grades to meet the diverse needs of global construction markets.

The product is manufactured using advanced hot-rolling technology, which is critical to its superior quality and black metal surface. During production, steel billets are heated to a high temperature (above 1000°C) to soften the material, then subjected to precision rolling to form the unequal L-shaped cross-section. This hot-rolling process refines the internal grain structure, eliminates internal defects such as pores, inclusions, and microcracks, and enhances the material's ductility and toughness. The natural black metal surface, formed by the oxidation of the steel during hot rolling, not only retains the material's inherent properties but also provides a foundation for subsequent surface treatments if needed.

The unequal cross-section design is a key feature of this angle bar, offering unique structural advantages. Unlike equal-angle steel, the unequal legs (one longer, one shorter) allow for flexible load distribution, making it particularly suitable for applications where uneven force bearing is required-such as supporting beams, wall brackets, and structural connections in buildings. In terms of specifications, the product offers a comprehensive range of dimensions: the longer leg length ranges from 30mm to 200mm, the shorter leg length from 20mm to 125mm, thicknesses from 3mm to 25mm, and standard lengths of 6m, 9m, and 12m. Custom lengths and special dimensions are available for bulk orders to meet project-specific requirements.

As a professional hot-rolled building material, this unequal angle bar is widely applied in various construction and industrial fields. In building engineering, it is used for building frames, roof trusses, floor joists, wall supports, balcony railings, and scaffolding. In industrial fabrication, it serves as supports for machinery, equipment bases, and factory frameworks. In infrastructure projects, it is utilized in bridge bracing, transmission towers, road guardrails, and drainage systems. Its unequal cross-section design also makes it suitable for special structural connections, such as beam-column joints and corner supports, demonstrating its versatility in building applications.

Each batch of this hot-rolled unequal angle bar undergoes strict quality control procedures to ensure consistent performance and reliability. Quality inspections include chemical composition analysis, mechanical property testing (yield strength, tensile strength, impact toughness), dimensional accuracy verification, and surface quality assessment. The black metal surface can be further treated with hot-dip galvanization, electro-galvanization, or painting to enhance corrosion resistance, extending its service life in outdoor, humid, or corrosive building environments. Combining high quality, diverse material options, and practical structural design, this unequal angle bar is a reliable choice for modern building projects worldwide.