76~660mm HFW Structural Welded Pipe Steel Frame Construction Tube

Product Description

76~660mm HFW Structural Welded Pipe Steel Frame Construction Tube is high-frequency straight seam circular hollow structural tube (CHS) specially produced for building steel frame, large-span truss and load-bearing support projects, covering complete outer diameter range of 76mm to 660mm. Strictly manufactured in accordance with EN10219-1/2, ASTM A500 Grade B, GB/T3094 structural hollow section standards, it adopts low-carbon structural steel grades S235JR, S275JR, S355JR, ASTM A500 Gr.B, featuring uniform round cross-section, excellent bidirectional compression and torsion resistance, widely used as building steel columns, roof trusses, factory workshop main frames, greenhouse skeletons, temporary scaffolding and municipal landscape support structures.

Adopting mature HFW high-frequency solid-state induction welding process, the weld achieves full metallurgical fusion with base metal without filler metal. Online internal & external welding flash removal plus weld normalization stress relief heat treatment eliminates welding residual stress, effectively avoiding weld deformation and cracking under long-term static load and seismic impact. All structural tubes pass mandatory flattening test, 180° cold bending test and full weld non-destructive inspection to guarantee stable bearing safety. Multiple surface treatments are available: black anti-rust oil, hot-dip galvanized, spray anti-rust primer, supporting customized fixed length, flat cut or beveled pipe ends. As a professional structural HFW pipe factory, we provide full-size series, flexible customization and stable bulk supply for global steel structure construction EPC projects.

## 1. Basic Product Specifications - \\Product Name\\: 76~660mm HFW Structural Welded Pipe Steel Frame Construction Tube - \\Executive Standards\\: EN10219-1/2, ASTM A500 Grade B, GB/T3094 Cold Formed Structural Hollow Section Standard - \\Outer Diameter Range\\: 76mm ~ 660mm full series structural CHS mainstream calibers - \\Wall Thickness Range\\: 2.0mm – 20mm, standard wall + custom thickened wall for heavy load steel columns - \\Structural Steel Grades\\: S235JR, S275JR, S355JR, ASTM A500 Gr.B low carbon structural steel - \\Production Process\\: Hot rolled coil slitting → multi-roll cold forming → HFW high-frequency ERW welding → internal & external burr removal → weld normalization heat treatment → sizing & straightening → fixed-length cutting → full structural performance inspection - \\Standard Length\\: 6m / 9m / 12m; custom arbitrary fixed length within 12m supported, mixed multiple lengths in one batch - \\Core Load-Bearing Characteristic\\: Balanced compressive & torsional rigidity, uniform stress distribution in all directions, superior seismic performance - \\Main Application Scenarios\\: High-rise building steel frame columns, large stadium exhibition hall truss, industrial factory main steel structure, agricultural multi-span greenhouse skeleton, building exterior scaffolding, bridge auxiliary support, municipal landscape railing, temporary construction platform - \\Pipe End Options\\: Plain flat cut ends, 30°~37.5° welding beveled ends, plastic anti-collision protective end caps - \\Surface Anti-Corrosion Options\\: Black anti-rust oil, hot-dip galvanized zinc coating, grey anti-rust primer spray - \\Core Features\\: Full 76–660mm OD structural tube series, HFW stress-relieved defect-free weld, excellent load-bearing & seismic performance, multiple structural steel grades optional, flexible length & surface customization, easy cutting/welding/bending on site, factory direct supply for steel frame construction

## 2. Core Product Advantages ### 2.1 Circular Hollow Section Superior Structural Mechanical Performance Round tube symmetric cross-section delivers equal strength in all directions, torsion resistance far exceeds I-beam and channel steel under the same weight, effectively resisting horizontal wind load and seismic force of buildings. Hollow design greatly reduces self-weight of steel frame, lowers foundation construction cost, ideal for large-span lightweight steel structures such as exhibition centers, gymnasiums and logistics warehouses.

2.2 Complete 76–660mm Full Caliber Series, One-Stop Steel Frame Procurement

Covers all medium and large diameter structural tube specifications required for steel column, truss and support frame, fully matched with EN/ASTM standard structural pipe fittings, connecting couplers and flanges. Steel structure contractors can complete all diameter centralized procurement from single factory, simplify multi-supplier logistics coordination, shorten project production cycle and reduce comprehensive supporting cost.

2.3 HFW Weld + Weld Normalization Treatment, Stable Long-Term Load-Bearing Safety

Flux-free high-frequency concentrated edge heating forms narrow heat-affected zone without coarse grain embrittlement. Independent online normalization heat treatment eliminates massive residual stress generated during forming and welding, avoiding delayed weld cracking under long-term static load, vibration and temperature alternating. Full weld UT/ET non-destructive inspection + flattening & cold bending test ensure no hidden structural defects, meet high safety factor requirements of permanent building steel frames.

2.4 Multiple Structural Steel Grades, Match Different Load Design Standards

S235JR: Light load temporary frame, greenhouse, scaffolding, cost-effective conventional structural material

S275JR: Medium load factory workshop, landscape support, medium-span truss

S355JR: Heavy load high-rise steel column, large-span stadium truss, high seismic zone building main frame

ASTM A500 Gr.B: North American standard steel structure export projects All grades feature good plasticity and weldability, convenient for on-site full penetration welding and bolt connection.

2.5 Diversified Anti-Corrosion Surface Solutions For Different Construction Environments

Black anti-rust oil: Indoor temporary steel frame, short-term construction projects, low cost

Spray anti-rust primer: Indoor permanent factory steel frame, easy for secondary top coat painting

Hot-dip galvanized coating: Outdoor overhead steel frame, coastal salt fog area, agricultural greenhouse, anti-rust service life up to 15–20 years

2.6 Strict Structural Special Inspection, Complete CE & MTR Acceptance Documents

All pipes adopt enhanced structural inspection standards: 180° cold bending test without crack, flattening test, full weld scanning inspection. Comply with EU CPR construction product regulation, support CE marking certification. Complete Mill Test Report, mechanical performance certificate and weld inspection report supplied per shipment, support SGS/BV third-party sampling inspection required by international steel structure bidding projects.

## 3. Dimensional Tolerance Standard (EN10219 & ASTM A500) | Inspection Item | Standard Tolerance | | ---- | ---- | | Outer Diameter (76mm–168mm) | ±0.8% nominal OD | | Outer Diameter (168mm–660mm) | ±1.0% nominal OD | | Wall Thickness | +12% / −10% nominal thickness; tighter tolerance for heavy load thick wall | | Pipe Straightness | ≤1.5mm per meter | | Out-of-Roundness | ≤1.0% of outer diameter | | Custom Cutting Length | +50mm / 0mm, high precision for structural assembly |

## 4. Mechanical & Chemical Properties (Structural Grade CHS) ### 4.1 Mechanical Properties | Steel Grade | Min. Yield Strength | Tensile Strength | Min. Elongation | Mandatory Factory Structural Test | | ---- | ---- | ---- | ---- | ---- | | S235JR | ≥235MPa | 360–510MPa | ≥26% | Flattening test, 180° cold bending test, full weld NDT inspection | | S275JR | ≥275MPa | 410–560MPa | ≥24% | Cold bending test, weld ultrasonic scanning | | S355JR | ≥355MPa | 470–630MPa | ≥22% | Impact sampling inspection, enhanced bending test | | ASTM A500 Gr.B | ≥310MPa | ≥400MPa | ≥20% | Reverse bend test, full weld eddy current inspection |

4.2 Maximum Allowable Chemical Composition (Mass %)

Note: All structural tubes pass flattening and cold bending test without weld crack; low-temperature Charpy impact test report can be customized for cold region seismic building projects.

## 5. Complete HFW Structural Tube Manufacturing Process 1. \\Raw Material Inspection\\: Inspect chemical composition and mechanical performance of EN/ASTM certified structural hot rolled coils, eliminate raw materials with high impurity content unfit for load-bearing construction. 2. \\Slitting & Edge Levelling\\: Precision slitting according to design wall thickness, grind strip edge oxide scale to guarantee uniform stable welding gap for high-strength structural weld. 3. \\Multi-Roll Continuous Cold Forming\\: Gradual rolling molding to ensure uniform roundness and consistent wall thickness of tube blank, meet EN10219 dimensional tolerance limits. 4. \\HFW High-Frequency Induction Welding\\: Closed-loop automatic parameter control, concentrated edge heating to realize full penetration solid-state metallurgical weld without filler metal. 5. \\Internal & External Weld Burr Removal\\: Online mechanical scarving to clear welding flash for smooth inner and outer tube surface, convenient for painting and galvanizing treatment. 6. \\Weld Normalization Stress Relief Heat Treatment\\: Eliminate welding and forming residual stress, improve weld anti-cracking performance under long-term building load and seismic impact. 7. \\Sizing & Straightening\\: Precision sizing mill calibrate outer diameter to standard tolerance, straightener correct tube linearity to avoid assembly deflection. 8. \\Numerical Control Custom Fixed-Length Cutting\\: Neat burr-free cutting according to steel frame project customized length, support mixed multiple length production in one container. 9. \\Structural Standard Full Inspection\\: Flattening test, 180° cold bending test, full weld non-destructive flaw detection, full dimensional reinspection. 10. \\Custom Surface Anti-Corrosion Processing\\: Black anti-rust oil / primer spray / hot-dip galvanized construction as per building indoor/outdoor laying environment. 11. \\Laser Permanent Marking\\: Mark execution standard, steel grade, OD×WT, batch number and surface treatment type on each tube body. 12. \\Steel Structure Export Packaging\\: Wear-resistant PE film wrapping to avoid scratch of galvanized/primer surface, bundled with high-strength steel strips, thick plastic anti-collision end caps to protect pipe ends during transportation and on-site welding assembly.

## 6. Main Steel Frame Construction Application Scope - Commercial & Public Building Steel Frame: High-rise office steel columns, stadium/exhibition hall large-span roof truss, airport terminal supporting structure - Industrial Factory Construction: Logistics warehouse main steel frame, manufacturing workshop load-bearing column, factory overhead support bracket - Agricultural Engineering: Single/multi-span vegetable & flower greenhouse skeleton, livestock breeding shed structural frame - Temporary Construction Engineering: Building exterior scaffolding, temporary construction platform, formwork support pipe - Municipal Landscape & Traffic: Road safety guardrail, park landscape support frame, bridge auxiliary load-bearing pipe - Global Structural EPC Projects: Overseas building steel frame, greenhouse and industrial construction projects complying with EN10219, ASTM A500 international structural standards

## 7. Quality Inspection & Factory Qualification Certification - Fully compliant with EN10219-1/2, ASTM A500 Grade B, GB/T3094 structural hollow section international standards, support CE marking for EU construction projects - ISO 9001 quality management system certified full HFW structural tube production line, independent structural performance inspection workshop - Dual independent inspection system: base tube weld & mechanical performance inspection + finished anti-corrosion coating thickness and adhesion inspection - Complete set of structural engineering official MTR test documents, weld inspection certificates and bending test records supplied per bulk shipment - Support SGS, BV third-party on-site sampling inspection required by global steel structure bidding and EPC contractors - Full batch traceability system covering structural steel coil raw material to finished structural tube delivery to construction sites

## 8. Packaging & Bulk Structural Project Delivery Arrangement - \\Packaging\\: Black bare structural tubes coated with anti-rust oil wrapped with thick waterproof PE film; galvanized/primer coated tubes with double-layer wear-resistant protective film to avoid coating scratch during transportation and welding, bundled with high-strength steel strips, thick plastic anti-collision caps installed at both pipe ends. - \\Product Marking\\: Laser permanent marking including execution standard, structural steel grade, outer diameter × wall thickness, batch number and surface anti-corrosion type. - \\Trade Terms\\: FOB, CIF, CFR, DAP global sea and land bulk delivery, support inland truck transport to steel structure construction sites - \\Main Shipping Ports\\: Tianjin, Qingdao, Shanghai, Ningbo, support full container mixed-length centralized loading for large steel frame project bulk orders - \\Customization Service\\: Arbitrary fixed length within 0.5–12m, mixed multiple lengths per order, adjustable wall thickness for heavy load columns, multi-type anti-corrosion coating and beveled pipe end processing - \\Delivery Cycle\\: Conventional stock structural tube specifications 7–12 working days; customized S355JR thick wall + hot-dip galvanized tubes 12–20 working days

## 9. Why Choose Our HFW Structural Pipe For Steel Frame Construction 1. Professional EN/ASTM standard structural HFW tube production line, full 76–660mm OD complete series for all building steel frame load-bearing specifications 2. Multiple structural steel grades (S235JR/S275JR/S355JR/ASTM A500 Gr.B) to match light, medium and heavy load building design requirements 3. Weld normalization stress relief treatment + full structural mechanical testing, eliminate weld cracking hidden danger under long-term building static load and earthquake impact 4. Circular hollow section with superior torsion & compression resistance, reduce steel frame self-weight and foundation investment cost 5. Diversified anti-corrosion coating customization, adapt to indoor factory, outdoor open-air, coastal salt fog and agricultural greenhouse different construction environments 6. Factory direct bulk supply without intermediate markup, sufficient spot inventory and complete CE/MTR bidding documents, long-term stable supplier for global steel structure EPC projects

## Contact Us For factory bulk wholesale quotations, detailed EN10219 structural technical data sheets, mechanical performance test reports, galvanized coating inspection certificates, large steel frame project order discounts and mass delivery schedules of \\76~660mm HFW Structural Welded Pipe Steel Frame Construction Tube\\, please contact our professional global steel structure sales team. As a reliable HFW structural CHS manufacturer, we supply full OD range structural welded tubes and one-stop anti-corrosion customized solutions for global high-rise building, industrial factory, greenhouse and large-span truss steel frame bulk procurement projects.

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