Carbon Steel Angle Section – Hot Rolled Structural Angle | Factory Direct | Huaxia-Steel
Carbon steel equal and unequal angle sections are the workhorses of welded fabrication, transmission towers, ship hulls, crane booms, building frames and general braced structures. Huaxia-Steel supplies factory-direct hot rolled carbon steel angle section per ASTM A36 / A572, EN 10056-1 / 10056-2 (European standard for equal / unequal leg structural angle), and GB/T 9787 / 9788 (Chinese standard). Equal-leg sizes run from 20×20 mm to 200×200 mm in leg length, with thickness 3 to 24 mm. Material grades include Q235B, Q355B, S275JR, S275J0, S355JR, S355J0, SS400, SM490, A36 and A572 Gr.50, all with EN 10204 Type 3.1 mill test certificate and optional third-party witnessed inspection by SGS / BV / Intertek before shipment.
1. Product Types and Tolerances
| Parameter | Equal angle | Unequal angle |
|---|---|---|
| Leg length range (a x b mm) | 20 x 20 to 200 x 200 | 30 x 20 to 200 x 100 |
| Thickness range (t mm) | 3 to 24 | 3 to 16 |
| Standard length | 6 m, 9 m, 12 m (other lengths to order) | 6 m, 9 m, 12 m |
| Tolerances – leg length | plus or minus 1 mm (small), plus or minus 2 mm (large) | plus or minus 2 mm each leg |
| Tolerances – thickness | per EN 10056-2 / ASTM A6 / GB 9787 | same |
| Squareness (90 deg leg) | plus or minus 1 deg | plus or minus 1.5 deg |
| Standard delivery | hot rolled, mill scale intact or shot blasted to Sa 2-1/2 | same |
| Weight (kg/m) | 0.89 (20x20x3) to 71.1 (200x200x24) | proportional |
The weight per metre is calculated as: kg/m = t x (a + b – t) x 0.00785 for unequal angle, and kg/m = t x (2a – t) x 0.00785 for equal angle, where a, b and t are in millimetres. This formula assumes square-edged profile; rounded radii reduce the weight by 1 to 3 percent in small sections.
2. Available Grades and Cross Reference
| EN 10025 | ASTM / AISC | JIS G3101 / G3106 | GB / T 1591 / 700 |
|---|---|---|---|
| S235JR | A36 (Grade 36) | SS400 | Q235B |
| S275JR / S275J0 | A36 / A572 Gr.42 | SS400 / SM400 | Q275 |
| S355JR / S355J0 | A572 Gr.50 | SM490 | Q355B |
| S355J2 | A572 Gr.50 | SM490YA | Q355C / Q355D |
| S460J0 / S460J2 | A572 Gr.65 | SM570 | Q460C / Q460D |
For most transmission tower, building brace and industrial rack applications, Q235B and Q355B grades cover the common duty. A572 Gr.50 is the high-strength choice when the leg stress exceeds 250 MPa and the structure would otherwise require a thicker section.
3. Chemical Composition (Typical Heat Analysis)
| Element (percent) | Q235B / S235JR | Q355B / S355JR | A36 | A572 Gr.50 |
|---|---|---|---|---|
| Carbon (C, max) | 0.20 (Q235B 0.22) | 0.20 (Q355B 0.20) | 0.25 | 0.23 |
| Manganese (Mn) | 1.40 max (Q235B 1.40) | 1.60 max (Q355B 1.70) | – | 1.35 max |
| Phosphorus (P, max) | 0.035 | 0.035 | 0.04 | 0.04 |
| Sulfur (S, max) | 0.035 | 0.035 | 0.05 | 0.05 |
| Silicon (Si) | 0.35 max (Q235B 0.35) | 0.50 max | 0.40 max | 0.40 max |
| CEV max | 0.35 | 0.43 | – | 0.45 |
Q235B / S235JR is the cost-effective choice for low-stress bracing and structural framing. Q355B / S355JR carries the higher CEV but allows higher stress and thinner sections, often cheaper overall when the steel-to-fabrication-labor ratio is high.
4. Mechanical Properties
| Property | Q235B / S235JR | Q355B / S355JR | A36 | A572 Gr.50 |
|---|---|---|---|---|
| Yield strength min (MPa) | 235 | 355 | 250 | 345 |
| Tensile strength (MPa) | 370 to 500 | 470 to 630 | 400 to 550 | 450 min |
| Elongation min (percent) | 26 (200 mm) | 22 (200 mm) | 20 | 18 |
| Charpy at 20 deg C (J) | 27 | 27 (B) | not required | optional |
| Charpy at 0 deg C (J) | optional | 27 (J0) | optional | optional |
| Charpy at -20 deg C (J) | not required | 27 (J2) | optional | optional |
For transmission towers in cold-climate installation, specify S355J0 or J2. For towers exposed to seismic risk or extreme low temperatures, J2 at -20 deg C is the safe minimum.
5. Manufacturing Standard Mapping
| Region | Standard | Title |
|---|---|---|
| USA | ASTM A6 / A36 / A572 Gr.50 | General Requirements for Rolled Structural Steel Shapes; Carbon Steel; High-Strength Columbium-Vanadium Steels |
| Europe | EN 10056-1, EN 10056-2, EN 10025-2 | Structural Steel Equal and Unequal Leg Angles; Hot Rolled Products in Non-Alloy Steels |
| Japan | JIS G3101, JIS G3106 | Rolled Steel for General Structure; Rolled Steel for Welded Structure |
| China | GB/T 700, GB/T 1591, GB/T 9787, GB/T 9788 | Carbon Structural Steels; High Strength Low Alloy; Hot Rolled Equal / Unequal Angle |
| Australia | AS 3679.1 | Structural Steel – Hot Rolled Bars and Sections |
| India | IS 2062 | Hot Rolled Medium and High Tensile Structural Steel |
Most export orders are dual-certified on the MTC – the steel complies with both ASTM A36 and EN 10025-2 S235JR on the same heat, because the mill runs the same chemistry across all customers and the dual-certified report allows the buyer to claim either standard for the project.
6. Common Applications
Carbon steel angle section is used in:
- Transmission towers (lattice steel legs, cross-arms) – typically Q355B / S355JR or A572 Gr.50
- Substation gantries and switchyard structures – Q355B / A36
- Building roof trusses and gable wall bracing – Q235B / A36
- Crane booms and jibs – Q355B / S355JR for high-stress sections
- Industrial racks and warehouse frames – Q235B / A36
- Solar PV mounting structures – Q235B / Q355B depending on wind zone
- Ship hulls – grades A, B, D, E, AH32 etc. ship-class structural angle
- Bridge bracing – A36 / A572 Gr.50 / S355JR
- General welded frames for machinery bases – any grade to suit
- Truck trailer and chassis – Q355B / S355JR
For corrosive service, the angle is typically hot dip galvanized per ASTM A123 after fabrication. Galvanizing adds 50 to 80 microns of zinc coating with a typical service life of 30 to 50 years in rural atmosphere.
7. Quality Assurance and Traceability
Every bundle of hot rolled carbon steel angle from Huaxia-Steel carries:
- Mill stamp at 1 m intervals with size, length, grade, heat number
- Bundle strap tag with heat number, weight, quantity, MTC reference
- Stencil on each piece (small sections – one stencil per bundle, large sections – one per piece) with heat number
- EN 10204 Type 3.1 mill certificate (Type 3.2 with third-party stamp optional)
- Visual inspection per ASTM A6 / EN 10056-2 / GB 9787
- Dimensional check on 5 percent of pieces per bundle
Third-party witnessed inspection by SGS, BV, Intertek, TUV or Lloyds Register can be arranged at the mill before shipment. Witnessed inspection adds 0.3 to 1.5 percent to the order value and is recommended for orders above 200 tonnes or for first-time suppliers.
8. Pack, Mark and Shipping
Standard export packing:
- Bundle strapped with steel banding at 2 m intervals
- Bundles ranged in 20 ft or 40 ft container
- Mill stamp on each piece visible on inspection
- Shipping marks on bundles per buyer’s requirement (e.g. “BUYER / ORDER NO. / HEAT NO. / SIZE / GRADE / PORT”)
- Wooden dunnage between bundles
- Fumigated wooden crate optional for delicate instrumentation hooks
A 20 ft container can hold approximately 22 to 25 tonnes of hot rolled equal angle in 100x100x10 mm; larger sections reach the weight limit earlier. A 40 ft container can hold approximately 26 to 28 tonnes.
9. Specification Checklist for RFQ
For a fast mill response, include the following on the inquiry:
- Profile type – equal or unequal, leg a x leg b (mm) x thickness (mm)
- Grade – per EN 10025 / ASTM / JIS / GB
- Quantity – pieces or tonnes
- Length – standard 6 / 9 / 12 m or custom cut
- Surface condition – hot rolled mill scale, shot blast Sa 2-1/2, painted, galvanized
- Tolerance – per EN 10056-2, ASTM A6 or GB 9787
- MTC – EN 10204 Type 3.1 or 3.2
- Marking – buyer’s specific shipping mark
- Inspection – mill standard or third-party witnessed
- Delivery – FOB, CIF, CFR or DDP; port of discharge
Request a Quotation
Huaxia-Steel is a mill-direct Chinese supplier of hot rolled carbon steel angle section (equal and unequal leg) per ASTM, EN, JIS and GB standards. We deliver Q235B / Q355B / S235JR / S355JR / A36 / A572 Gr.50 / SS400 / SM490 with full EN 10204 3.1 mill certificate, optional third-party inspection, and bundle-marked shipments. Send your section size, grade, quantity, surface and target port to [email protected] for a complete offer.
