


Huaxia-Steel manufactures and exports carbon steel square bars in hot-rolled and cold-drawn conditions. Square bars provide excellent torsional rigidity, clean joining surfaces, and efficient material utilization for frames, gates, railings, and machine bases. We supply standard merchant bars and precision cold-drawn squares with sharp corners or full-radius edges, tailored to your fabrication requirements.
Product Overview
Carbon steel square bar is a solid section product with equal width and height dimensions. Hot-rolled square bars feature mill scale and slightly rounded corners, suitable for welded structures and general fabrication. Cold-drawn square bars offer precise dimensions, smooth bright surfaces, and enhanced strength for machined components and precision assemblies.
Specifications
| Parameter | Range / Standard |
|---|---|
| Size (side length) | 5mm x 5mm to 200mm x 200mm |
| Length | 3m, 6m, 9m, 12m, or custom |
| Corner Radius | Sharp (0.5mm max) or standard (1.5-3mm) |
| Tolerance | Standard (+/- 0.5mm), precision (+/- 0.05mm CD) |
| Straightness | 2mm/m (HR), 0.5mm/m (CD) |
Available Grades
- Structural: ASTM A36, Q235B, S235JR, S275JR, S355JR, SS400
- Machinery: SAE 1020, SAE 1045, S45C, S50C, C45, C50
- Free-machining: 1215, 12L14, 11SMn30
- Case-hardening: SAE 1018, 20CrMnTi, 20MnCr5
Manufacturing Standards
Hot-rolled square bars are produced on continuous or reversing mills from heated billets, conforming to ASTM A29, JIS G3101, and EN 10025. Cold-drawn squares are produced by drawing round bar through a shaped die or by flat rolling and drawing, achieving precise corner geometry and surface finish.
All bars are traceable to heat number and mill of origin. Mill test certificates include chemical composition, mechanical properties, and dimensional verification per EN 10204 3.1 or 3.2.
Applications
- Machine tool frames and bases
- Conveyor frames and support structures
- Security gates, fences, and railings
- Architectural metalwork and furniture
- Shaft keys and locking components
- Press dies and fixture components
- Agricultural equipment frames
- General welded and bolted structures
Quality Assurance
Each production batch is inspected for dimensional accuracy (caliper and micrometer across flats and diagonals), straightness, surface quality, and corner radius. Mechanical testing includes tensile test and hardness test. For structural grades, bend testing confirms ductility. Third-party inspection is available for export orders.
Packing and Shipping
Square bars are bundled with steel strapping (1-3 tons per bundle) and tagged with heat number, grade, and size. For cold-drawn precision bars, protective wrapping with oiled paper or VCI film prevents rust. Export containers use wooden dunnage and edge protectors to prevent bundle shifting and surface damage during ocean transit.
Request a quote for carbon steel square bars today. Specify size, grade, delivery condition, quantity, and destination. Huaxia-Steel delivers competitive mill-direct pricing with 7-15 day lead time for standard sizes and full certification.





