Product Overview
Huaxia-Steel supplies hot-rolled carbon steel square bars in sizes from 10 × 10 mm to 200 × 200 mm, directly from Chinese rolling mills to international buyers. Square bar combines the machining convenience of round bar with the flat-sided geometry needed for keyways, slides, and structural connections where wrench flats or square mortises are required.
We stock and roll square bars to GB/T 702, ASTM A29, and EN 10058 tolerances, in grades from Q235B/S235JR to S45C/1045/C45, with mill cutting to length and EN 10204 3.1 certification on every shipment.
Standard Sizes and Weight Table
| Size (mm) | Weight (kg/m) | Common Lengths |
|---|---|---|
| 10 × 10 | 0.79 | 3 – 6 m |
| 16 × 16 | 2.01 | 3 – 6 m |
| 20 × 20 | 3.14 | 3 – 6 m |
| 25 × 25 | 4.91 | 3 – 6 m |
| 30 × 30 | 7.07 | 3 – 6 m |
| 40 × 40 | 12.56 | 3 – 6 m |
| 50 × 50 | 19.63 | 3 – 6 m; 5.8 m for containers |
| 60 × 60 | 28.26 | 3 – 6 m |
| 80 × 80 | 50.24 | 3 – 6 m |
| 100 × 100 | 78.50 | 3 – 6 m; 5.8 m for containers |
Larger sizes up to 200 × 200 mm available by hot forging or continuous casting with 25 – 40 day lead time. Non-standard sizes and tight tolerances (+/−0.5 mm) available on request.
Dimensional Tolerances
| Parameter | Tolerance (hot-rolled, GB/T 702) |
|---|---|
| Width ≤ 25 mm | ±0.3 to ±0.5 mm |
| Width 25 – 50 mm | ±0.4 to ±0.6 mm |
| Width 50 – 100 mm | ±0.6 to ±0.8 mm |
| Width > 100 mm | ±0.9 to ±1.2 mm |
| Corner radius | ≤ 2.0 mm (typical for hot-rolled) |
| Straightness | ≤ 4 mm per meter; ≤ 0.4% of total length |
| Length tolerance | +50 / 0 mm standard; ±3 mm precision cut on request |
Available Grades
| Grade | Standard | Yield (Min) | Typical Use |
|---|---|---|---|
| Q235B / S235JR | GB/T 700 / EN 10025-2 | 235 MPa | Structural frames, brackets, general fabrication |
| SS400 | JIS G3101 | 245 MPa | Japanese-standard structures |
| S45C / 1045 / C45 | JIS G4051 / ASTM A29 / EN 10083-2 | 345 MPa | Shafts, keys, machine parts requiring strength |
| S20C / 1020 / C22 | JIS G4051 / ASTM A29 / EN 10083-2 | 245 MPa | Cold-formed parts, welded components |
Manufacturing Standards
- Dimensional standards: GB/T 702, ASTM A29, EN 10058
- Material standards: GB/T 700, GB/T 1591, JIS G3101, JIS G4051, ASTM A29, EN 10025-2, EN 10083-2
- Rolling: hot-rolled from continuously cast billets; delivery condition +AR or +N
- Certification: EN 10204 3.1 mill test certificate with heat-number traceability
Applications
- Machine keys and key stock for shaft couplings
- Slide rails and guide bars in automation equipment
- Structural connections where wrench flats or square mortises are needed
- Forging feedstock for crankshafts, connecting rods, and hammer heads
- Grating frames, railing posts, and architectural metalwork
- Cold-formed brackets and clamps (low-carbon grades)
Quality Assurance
- Heat-number traceability from ladle analysis to each bundle
- Tensile testing per lot; results reported on EN 10204 3.1 certificate
- Dimensional inspection against GB/T 702 / EN 10058 tolerances before packing
- Straightness check on long bars; end-squareness verified on cut pieces
- Surface standard: free of rolled-in scale pits, cracks, and laps
- Optional third-party inspection (SGS, BV, TUV, Intertek) at mill before shipment
Packaging and Shipping
- Standard bundles 2 – 4 tonnes, secured with steel strapping and end caps
- Heat-number tags wired to each bundle; packing list cross-referenced
- 20ft container: up to ~26 tonnes in bundles (5.8 m standard length)
- IPPC-compliant wooden dunnage; seaworthy packaging standard
- FOB, CFR, CIF, DAP terms; ports of loading: Tianjin, Qingdao, Shanghai
Why Buy Square Bar from Huaxia-Steel
- Factory-direct pricing from rolling mills, no trading layers
- Wide size range and grade selection from a single source
- Cut-to-length service (±3 mm precision) reducing your waste
- 15+ years export experience; documentation accepted worldwide
Request a Quote
Send us your size, grade, and quantity for pricing within 24 hours. Mixed sizes and grades in one container are our specialty. Email [email protected] or use the inquiry form below.
