Our high-quality cold-formed and hot-finished hollow steel sections include square, rectangular, and circular tubes, widely used in building structures, bridges, machinery, energy facilities, and industrial frameworks. Made from premium carbon steel via high-frequency welding (HFW) or seamless hot-rolling, these sections offer uniform cross-section, high dimensional accuracy, stable mechanical properties, and excellent weldability. Compared to traditional angles and channels, hollow sections provide superior torsional rigidity and structural efficiency-making them the ideal choice for modern lightweight, high-strength structural design.
Key Features
Standards:
International:
EN 10210-1/-2 (Hot-finished welded & seamless structural hollow sections)
EN 10219-1/-2 (Cold-formed welded structural hollow sections)
ASTM A500 (Cold-formed carbon steel structural tubing)
ASTM A501 (Hot-formed carbon steel structural tubing)
ISO 21610 (Seamless and welded steel tubes for structural use)
Chinese:
GB/T 6728 "Cold-formed Structural Hollow Sections"
GB/T 30067 "Hot-rolled Structural Hollow Sections for High-strength Applications"
JG/T 492 "Welded Steel Tubes for Building Structures"
Custom: Available per customer drawings or technical specs.
Materials:
Carbon Structural Steels:
Q235B/C/D, Q355B/C/D/E (GB/T 700 & 1591)
S235JR, S355JO, S355J2H,S460NH (EN 10025, for export)
Special Grades:
Weathering Steel: Q355NH, Q460NH (for outdoor, paint-free structures)
Z-Toughness Steel: Q355D-Z15/Z25 (for thick-section welded joints)
Process Types:
Cold-Formed Welded (EN 10219 / GB/T 6728): High precision, smooth surface
Hot-Finished (EN 10210 / ASTM A501): Low residual stress, suitable for heavy loads
Seamless: For high-fatigue, weld-free applications
Dimensions:
Square/Rectangular: 20×20 – 600×400 mm, WT: 1.5–30 mm
Circular: OD: 21.3–630 mm, WT: 1.5–30 mm
Length: Fixed (6m, 12m) or multiple, up to 14m
Tolerances (EN 10219 Level 1 / GB/T 6728):
Dimension: ±0.8%
Wall Thickness: +10% / -7.5%
Straightness: ≤2 mm/m
Applications:
Buildings: Trusses, space frames, curtain walls, handrails;
Bridges: Pedestrian, light rail, highway bridge beams;
Machinery: Conveyor supports, equipment frames;
Renewables: PV mounts, wind tower internal structures;
Industrial: Heavy racks, pipe bridges, platforms;
Stadiums & Exhibitions: Roofs, domes, stage structures.
Certifications:
Classification Society Approvals:
For offshore or marine-related applications:
CCS, ABS, BV, LR material & inspection support
Mill Test Certificates (MTC Type 3.1/3.2) with class stamp available.
End-User & Engineering Company Qualifications:
Approved by:
Owners: CSCEC, CREC, CRCC, China Resources, Vanke, SPIC
EPCs: CSCEC Steel, Shanghai Construction, ECADI, CPECC, Beijing Urban Construction
International Projects: Supplied to landmark buildings in Middle East, SE Asia, Africa.
Quality & System Certifications:
ISO 9001:2015, ISO 14001:2015, ISO 45001:2018
GB/T 6728 Compliance Statement
Full traceability via heat/lot number system
Common Customer Questions (Q&A Format)
Q: Are your hollow sections welded or seamless? What's the difference?
A: We offer cold/hot-formed welded (standard) and seamless (special). Welded: high precision, cost-effective. Seamless: no weld, higher fatigue strength for critical zones.
Q: Do you comply with EN 10210 or ASTM A500? Suitable for export projects?
A: Yes, we produce to EN 10210, EN 10219, ASTM A500/A501, and have exported to Middle East, SE Asia, Africa.
Q: Can you supply Q355D or S355J2H? Does it meet -20°C impact requirements?
A: Yes, Q355D (-20°C), Q355E (-40°C), S355J2H (-20°C) are standard grades for low-temperature applications.
Q: What is your maximum square tube size? Suitable for large-span space frames?
A: Up to 600×400×30mm-ideal for large-span structures like airports and exhibition centers.
Q: Are you approved by CSCEC, CREC, or other major Chinese contractors?
A: Yes, we are qualified supplier for CSCEC, CREC, SPIC, and others, with products used in key national projects.
Q: What is the lead time? Do you have stock for common sizes?
A: Lead time: 25–40 days. Common sizes (e.g., 50×50×3, 100×100×5) are in stock for fast delivery.
Q: Do you offer end finishing like beveling or drilling?
A: Yes, we provide end chamfering, V-groove, hole drilling, laser cutting to reduce on-site work.
Q: Can you manufacture non-standard or special-shaped sections?
A: Yes, custom sizes available. Special shapes (e.g., oval, D-tube) require mold cost and MOQ evaluation.
Q: What is your export packaging? Suitable for sea freight?
A: Rust preventive oil, plastic end caps, steel strapping in hex bundles, moisture-proof pads, secured on pallets-safe for long-haul ocean transport.
Q: Can you support third-party inspection (e.g., SGS, BV, client witness)?
A: Yes. We fully support third-party inspections (witness/surveillance) and provide complete inspection records and reports.
Q: Do you have FPCC certificates for Singapore Market.
A: Yes. Our mills are approved with FPCC.
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