A36 SS400 Q235 Q345B Construction MS (Mild Steel) Angle Steel Bar, featuring a standardized 100X100X5mm equal leg dimension, hot-rolled manufacturing, and optional slotted profile, is a high-performance structural steel product specifically engineered for construction applications. Characterized by its iconic L-shaped cross-section-available in both standard and slotted configurations-this mild steel angle bar integrates the grade-specific mechanical properties of four globally recognized steel grades (A36, SS400, Q235, Q345B) with the durability of hot-rolled iron angle, making it an indispensable component in residential, commercial, and industrial building projects. Designed to deliver exceptional load-bearing capacity, excellent workability, and precise dimensional accuracy, it adheres to strict international and national standards, catering to the rigorous structural requirements of modern construction.
As a construction-focused MS (Mild Steel) angle steel bar, it features a controlled low-carbon composition (ranging from 0.12% to 0.28% depending on the grade), which is the foundation of its superior workability and adaptability to construction scenarios. Mild steel endows the product with excellent formability, allowing for easy cutting, punching, bending, and drilling using standard construction equipment-critical for on-site fabrication, customization, and quick installation. Additionally, its carbon-rich matrix ensures superior weldability, compatible with common welding methods such as arc welding, gas welding, and resistance welding, enabling seamless integration with other structural components (e.g., beams, columns, purlins, and concrete reinforcements) without the need for pre-heating or special additives.
This construction angle steel bar is available in four globally recognized grades, each tailored to meet specific mechanical requirements, ensuring adaptability to light, medium, and heavy-duty construction applications:
A36: An American standard (ASTM) mild carbon structural steel grade, renowned for its balanced performance and cost-effectiveness. It features a minimum yield strength of 250 MPa, a tensile strength range of 400–550 MPa, and a minimum elongation of 20%. Ideal for general construction components such as building frames, roof trusses, and bracing, it is a staple in global construction projects due to its reliable performance and wide compatibility.
SS400: A Japanese standard (JIS G 3101) mild carbon structural steel grade, equivalent to A36 in performance. With a minimum yield strength of 245 MPa and a tensile strength range of 400–510 MPa, it exhibits excellent ductility and weldability. Widely used in Asian construction markets, it is suitable for light to medium-duty applications such as equipment supports, wall partitions, and foundation reinforcements.
Q235: A Chinese national standard (GB/T 700-2006) mild carbon structural steel grade, valued for its affordability and balanced properties. It has a minimum yield strength of 235 MPa, a tensile strength range of 375–500 MPa, and a minimum elongation of 26%. Perfect for light-duty construction components like shelving, brackets, and temporary formwork, it is one of the most widely used grades in Chinese construction projects.
Q345B: A Chinese national standard (GB/T 1591-2018) low-alloy high-strength steel grade, offering enhanced load-bearing capacity compared to the other three grades. It features a minimum yield strength of 345 MPa, a tensile strength range of 470–630 MPa, and improved toughness and fatigue resistance (tested at 20°C). The addition of trace alloying elements refines its grain structure, making it ideal for heavy-duty construction applications such as high-rise building frames, bridge bracing, and crane supports.
The product's standardized 100X100X5mm equal leg dimension is a key highlight for construction use, providing balanced load distribution across both perpendicular 100mm legs with a uniform 5mm thickness. This dimension strikes an optimal balance between weight and strength: it is robust enough to withstand heavy static loads in building frameworks, yet lightweight enough to facilitate transportation, handling, and on-site installation. The equal leg design ensures symmetrical support, making it ideal for framing, bracing, and reinforcement in symmetrical structural configurations.
An optional yet valuable feature is its slotted profile, which enhances installation efficiency in construction projects. The prefabricated slots along one or both legs eliminate the need for on-site drilling, allowing for quick alignment, adjustment, and connection with bolts or fasteners. This not only saves labor time but also ensures precise positioning, reducing errors in structural assembly-particularly beneficial for modular construction, adjustable brackets, and temporary or permanent framing systems that require frequent modification or disassembly.
Manufactured via advanced hot-rolling technology, this MS angle steel bar undergoes a rigorous production process to ensure quality and precision. Raw steel billets (conforming to the chemical specifications of each grade) are first subjected to strict pre-inspection to verify purity and composition. The billets are then heated to a controlled high temperature (1100°C–1250°C) to maximize plasticity, eliminating brittleness and enabling seamless shaping. Subsequently, the heated billets are passed through calibrated rolling mills to form the 100X100X5mm L-shaped cross-section (with optional slots), ensuring uniform thickness, tight dimensional tolerances (±0.3mm for leg length and ±0.2mm for thickness), and a refined grain structure. This hot-rolling process further enhances mechanical properties and creates a slightly textured surface that promotes strong adhesion with welding materials and surface coatings.
To extend its service life in harsh construction environments (e.g., outdoor, humid, or industrial settings), the angle steel bar can be equipped with optional surface treatments. Hot-dip galvanizing, anti-corrosive painting, or powder coating forms a protective barrier against moisture, rust, and environmental pollutants, preventing corrosion and reducing long-term maintenance costs-critical for ensuring the longevity of building structures.
Rigorous quality control measures are implemented throughout production and inspection to uphold product integrity. Each batch undergoes comprehensive testing, including chemical composition analysis (to verify grade compliance), mechanical property evaluation (yield strength, tensile strength, elongation, and impact toughness), dimensional accuracy checks, slot precision inspections (for slotted profiles), and surface quality assessments. Defects such as cracks, inclusions, uneven thickness, and surface scratches are strictly eliminated, ensuring every piece meets or exceeds international/national standards and construction project requirements.
In summary, A36 SS400 Q235 Q345B Construction MS Angle Steel Bar 100X100X5 Hot Rolled Iron Angle Size Slotted Profile Steel is a versatile, high-performance structural material tailored for construction applications. Its diverse grade options, standardized 100X100X5mm dimension, optional slotted profile, hot-rolled durability, and excellent workability make it suitable for a wide range of construction needs-from light-duty brackets to heavy-duty framing. Backed by strict quality control and compliance with global standards, it delivers consistent performance, easy installation, and long-term durability, making it the trusted choice for engineers, contractors, and builders worldwide.
| EQUAL ANGLE BAR DIMENSION-I (MM) | ||
| A*B | t | UNIT WEIGHT (KG/M) |
| 20*20 | 3/4 | 0.889/1.145 |
| 25*25 | 3/4 | 1.124/1.459 |
| 30*30 | 3/4 | 1.373/1.786 |
| 36*36 | 3/4/5 | 1.656/2.163/2.654 |
| 40*40 | 3/4/5 | 1.852/2.422/2.976 |
| 45*45 | 3/4/5/6 | 2.088/2.736/3.369/3.985 |
| 50*50 | 3/4/5/6 | 2.332/3.059/3.770/4.465 |
| 56*56 | 3/4/5/8 | 2.624/3.446/4.251/6.568 |
| 60*60 | 4/5 | 3.68/4.55 |
| 63*63 | 4/5/6/8 | 3.907/4.822/5.721/7.469 |
| 65*65 | 5/6/8 | 5.00/5.91/7.66 |
| 70*70 | 4/5/6/7/8 | 4.372/5.397/6.406/7.398/8.373 |
| 75*75 | 5/6/7/8/10 | 5.818/6.905/7.976/9.030/11.089 |
| 75*75 | 9 | 9.96 |
| 80*80 | 5/6/7/8/10 | 6.211/7.376/8.525/9.658/11.874 |
| EQUAL ANGLE BAR DIMENSION-II (MM) | ||
| A*B | t | UNIT WEIGHT (KG/M) |
| 90*90 | 6/7/8/10/12 | 8.350/9.656/10.946/13.476/15.940 |
| 90*90 | 13 | 17.0 |
| 100*100 | 7/8/10/12/14 | 10.830/12.276/15.120/17.898/20.611 |
| 100*100 | 13 | 19.1 |
| 110*110 | 7/8/10/12/14 | 11.928/13.532/16.690/19.782/22.809 |
| 120*120 | 8 | 14.7 |
| 125*125 | 8/10/12/14 | 15.504/19.133/22.696/26.193 |
| 130*130 | 9/12/15 | 17.9/23.4/28.8 |
| 140*140 | 10/12/14/16 | 21.488/25.522/29.490/33.393 |
| 150*150 | 12/15/19 | 27.3/33.6/41.9 |
| 160*160 | 10/12/14/16 | 24.729/29.391/33.987/38.518 |
| 180*180 | 12/14/16/18 | 33.159/38.383/43.542/48.634 |
| 200*200 | 14/16/18/20 | 42.894/48.680/54.401/60.056 |
| 200*200 | 15/25 | 45.3/73.6 |
