Carbon Square Steel Bar - ASTM Certified Mill Direct Supplier

Technical Specifications of Carbon Square Steel Bar

Carbon Square Steel Bar - ASTM Certified Mill Direct Supplier

Carbon square steel bar is a fundamental structural product valued across construction, manufacturing, and heavy industrial sectors for its combination of mechanical strength, machinability, and cost efficiency. As a mill-direct supplier with ASTM-certified inventory, we deliver premium-grade carbon square bars in a comprehensive range of sizes and steel grades to meet demanding project specifications. Whether you require hot-rolled or cold-drawn profiles for structural frameworks, machine components, or fabrication stock, our carbon square steel bars are produced under strict quality management systems to ensure dimensional accuracy, consistent chemical composition, and reliable mechanical performance. With direct access to integrated steel mills, we offer competitive mill-direct rates, flexible order quantities, and global shipping capabilities that streamline your procurement process.

What Is Carbon Square Steel Bar?

A carbon square steel bar is a solid steel product with a square cross-section manufactured from carbon steel grades ranging from low-carbon (AISI 1018/1020) to medium-carbon (AISI 1045) and high-carbon (AISI 1060–1095) compositions. These bars are produced through hot-rolling or cold-drawing processes, yielding profiles that serve critical roles in structural supports, shafting, axles, anchor bolts, grating, and general machining stock. The carbon content—typically between 0.18% and 0.95%—directly governs hardness, tensile strength, and weldability, allowing engineers to select the optimal grade for each application.

Carbon Square Steel Bar Technical Specifications

Our carbon square steel bars conform to internationally recognized standards, ensuring consistent quality for critical applications. Below are the key technical parameters:

• Applicable Standards: ASTM A36, ASTM A529, ASTM A576, EN 10025 S235JR/S355JR, JIS SS400
• Side Dimensions: 8 mm × 8 mm to 250 mm × 250 mm
• Lengths: 6 m, 9 m, 12 m standard; custom cut-to-length available
• Carbon Content: 0.18%–0.95% depending on grade
• Tensile Strength: 400–850 MPa (e.g., ASTM A36 minimum yield strength of 250 MPa, tensile strength of 400–550 MPa)
• Density: 7.85 g/cm³ at 20°C
• Surface Finish: Black (as-rolled), peeled, ground, or polished per customer requirement
• Tolerances: Compliant with ASTM A6/A6M dimensional tolerances for hot-rolled bars

Cold-drawn carbon square bars offer tighter dimensional tolerances (typically ±0.05 mm) and superior surface quality compared to hot-rolled equivalents, making them ideal for precision machining applications where minimal post-processing is required.

Applications of Carbon Square Steel Bars

Carbon square steel bars find extensive application across diverse industries. In construction, ASTM A36 square bars serve as structural bracing, column reinforcements, and base plates. In manufacturing, medium-carbon grades like AISI 1045—with a tensile strength of approximately 585 MPa in the normalized condition—are selected for shafts, gears, studs, and machine keys requiring balanced strength and toughness. High-carbon variants support tooling, spring manufacturing, and wear-resistant components where hardness values exceeding 55 HRC after heat treatment are achievable.

Get a Competitive Quote for Carbon Square Steel Bar

Partner with a trusted mill-direct supplier committed to delivering superior quality carbon square steel bars at cost-effective pricing. Our dedicated team provides end-to-end support—from grade selection and technical consultation to logistics coordination and after-sales service.

• 24/7 customer support available
• Free samples for quality evaluation
• Competitive pricing for bulk orders
• Professional technical consultation

Contact us today to get your free quote within 24 hours!