Description
Direct Mill Supply — Seamless S355JRH square hollow sections produced and tested under one roof, eliminating third-party material sourcing risks.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355JRH/J0H/J0H/J2H/K2H/NH Seamless Square Steel Tube |
| Product Type | Seamless Square / Rectangular Steel Tube (Hollow Section) |
| Steel Grade | S355JRH, S355J0H, S355J2H, S355K2H, S355NH, S460, S690 |
| Standard | EN10210, EN10219, ASTM A500, ASTM A501, JIS G3444, JIS G3466, EN, GB |
| Section Shape | Square / Rectangular |
| Technique | Seamless Manufacturing Process |
| Surface Treatment | Hot Rolled |
| Tolerance | ±1% |
| Surface | Smooth |
| Special Pipe | Thick Wall Pipe |
| Processing Service | Welding, Punching, Cutting, Bending, Decoiling |
| Delivery Time | 15-21 days |
| Invoicing | By Theoretical Weight |
| Packing | Standard Seaworthy Packing |
| Payment Terms | L/C, T/T (30% DEPOSIT) |
| Inspection | Self-Inspection, Third Party Inspection Accepted |
| MOQ | 10 Tons |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Heavy-Duty Engineering | Bridge and highway construction, port infrastructure, stadium structural frames |
| High-Rise Construction | Steel frame structures, glass curtain wall framing, high-rise building columns and beams |
| Prefabricated Building | Modular structure systems, prefabricated building frames, industrial framing |
| Infrastructure Development | Heavy-duty engineering supports, construction frames for large-span facilities |
When Dimensional Tolerance Decides Whether a Structural Frame Passes Inspection
A ±1% tolerance on a thick-wall S355JRH seamless square steel tube is not a marketing line — it is the difference between bolt holes aligning on-site and an entire column section getting rejected at assembly.
Overseas buyers outsourcing structural steel fabrication face a recurring problem: the mill test certificate looks perfect on paper, but the physical tubes arriving at the port do not match. Wall thickness drifts beyond negative tolerance, corner radii are inconsistent, and the dimensional deviation causes connection plates to misalign. The result is costly rework, delayed project schedules, and in worst cases, structural safety concerns that trigger full-batch rejection by the project engineer [NEED_CITE: EN 10210 hot finished structural hollow section dimensional tolerance requirements]. When procurement is fragmented across multiple suppliers, material traceability breaks down — and no amount of paperwork can fix a batch that fails third-party re-inspection at the destination port.
How Thick-Wall Seamless S355JRH Tubes Match Heavy Structural Demands
The seamless manufacturing process produces S355JRH seamless square steel tube with uniform wall thickness and consistent corner geometry, which is critical for moment-resisting connections in heavy-duty engineering frames. The thick wall capability allows these hollow sections to carry higher axial loads in bridge supports, port crane structures, and stadium roof trusses where welded connections must transfer full section capacity. Hot rolled surface finish provides a clean, smooth profile ready for welding, painting, or further coating without secondary surface preparation. For high-rise building frames, the ±1% dimensional tolerance ensures that prefabricated connection assemblies fit precisely during erection, reducing crane time and labor costs on-site.
Structural Compliance Across EN, ASTM, and JIS Frameworks
Engineering specifications for heavy infrastructure projects frequently call for compliance with EN10210 for hot finished seamless hollow sections in European markets, ASTM A500 Grade C for North American construction, or JIS G3444 for Asia-Pacific structural applications. The S355JRH grade meets EN10219 cold-formed requirements while the seamless process delivers the isotropic mechanical properties that hot finished standards demand. For projects requiring low-temperature impact performance, S355J2H and S355K2H grades provide certified Charpy V-notch values at sub-zero test temperatures, while S355NH offers normalized delivery conditions for enhanced weldability in thick sections [NEED_CITE: steel grade equivalence mapping between EN 10210 and ASTM A500 standards]. Third-party inspection by SGS, BV, DNV, or LR is accepted before shipment, providing independent verification that the material chemistry and mechanical properties match the certified standard.
Understanding S355 Series Grades and Seamless Manufacturing
The S355 grade family spans multiple impact toughness designations — JR for room temperature testing, J0 for 0°C, J2 for -20°C, and K2 for -20°C with higher impact energy — allowing engineers to specify the appropriate toughness level for the service environment. The seamless manufacturing process eliminates the longitudinal weld seam present in ERW tubes, providing uniform strength around the entire cross-section and superior performance under dynamic or cyclic loading conditions typical in bridge and port structures. High-strength options including S460 and S690 grades extend the range for projects requiring reduced section sizes while maintaining load capacity. Hot rolled surface treatment delivers a mill-scale finish suitable for immediate fabrication, while the ±1% tolerance on dimensions ensures that theoretical weight invoicing aligns with actual material delivered — a point of frequent dispute when negative tolerance exceeds acceptable limits [NEED_CITE: impact of negative tolerance on theoretical weight invoicing in structural steel procurement].
The Hidden Cost of Procuring Without Verified Material Traceability
Ordering S355JRH seamless square steel tube from a supplier who sources raw material from third-party mills creates a chain of custody gap — the mill test certificate may reference a heat number that cannot be traced back to the original steelmaking batch. When customs authorities or project inspectors request verification, the documentation fails, and the entire shipment faces detention at the port. Material substitution — receiving a lower grade stamped with S355 markings — creates structural safety risks that only surface during load testing or, worse, after the structure is in service. Non-compliant dimensional tolerance leads to connection failures during erection, forcing field modifications that compromise the engineered design [NEED_CITE: consequences of material certification gaps in international structural steel supply chains]. The cost of re-inspection,返工, and schedule delay far exceeds the price difference between verified mill-direct supply and the cheapest available offer.
Why Project Teams Source S355JRH Seamless Square Steel Tube From Our Mill
Our vertically integrated operation combines steel production with structural fabrication under one quality management system, meaning every S355JRH seamless square steel tube is produced, tested, and documented from a single source of accountability. The in-house理化实验室 performs chemical composition analysis and mechanical testing on every heat, with results recorded in the mill test certificate before material leaves the facility. With 2,800+ specifications in stock across multiple steel grades and standards, project teams can consolidate their structural steel procurement — from raw hollow sections to fabricated components with welded connections, drilled plates, and custom assemblies — through one purchase order and one quality system. Our welding procedures and welders hold AWS and EN certification, and the complete documentation package includes WPS, PQR, weld maps, dimensional inspection reports, and coating reports required for international project handover. Professional loading and lashing planning handles oversized fabricated components, while export documentation and tracking ensure delivery from our Jinan facility to project sites across the EU, Middle East, Southeast Asia, and Africa.
Documentation & Compliance
- Mill test certificate documenting S355JRH chemical composition and mechanical properties per EN10210, with heat number traceability to the original steelmaking batch
- CE certificate confirming EN10210/EN10219 compliance for hot finished seamless structural hollow sections exported to European Union markets
- ISO 9001 quality management system certificate covering the full production process from raw material procurement through final inspection
- SGS or BV third-party inspection report available upon request, verifying dimensional tolerance, surface quality, and material certification before shipment
- Material traceability documentation linking each tube to its heat number, with test results for chemical composition, yield strength, tensile strength, and impact toughness where applicable
- Complete customs documentation package including packing list, bill of lading, and certificate of origin for clearance at destination ports
Packaging, Loading & Delivery
- Thick-wall S355JRH seamless square steel tubes bundled with steel strips and edge protectors to prevent surface damage during ocean transit, with hot rolled surface preserved under standard seaworthy packaging
- Non-oiled smooth surface tubes packed in hexagonal or rectangular bundles sized to optimize 20ft and 40ft container loading, with bundle weight calculated to match port handling equipment capacity
- Custom cutting to project-specified lengths available before packing, reducing on-site cutting waste and supporting just-in-time delivery to construction sites
- Heat number and steel grade markings stenciled on each bundle, with color-coding applied to distinguish S355JRH from S355J2H or S460 grades during site identification
- FOB, CIF, and DDP shipping terms available, with professional oversized cargo loading plans for heavy-wall sections and fabricated components destined for project sites worldwide
- Typical production lead times of 15-21 days from order confirmation, with material procurement and production scheduled upon drawing approval and deposit receipt
Getting Your S355JRH Seamless Square Steel Tube Quotation Started
Submit your project drawings in PDF or DWG format along with the required steel grades, section dimensions, wall thickness, total quantity, and destination port. Our engineering team responds within 24 hours with a preliminary assessment, followed by a detailed quotation covering material, fabrication, coating, packing, and shipping costs — including shop drawing timeline and production schedule. Once drawings are approved and the contract signed, material procurement and production begin immediately, with full quality documentation prepared throughout the fabrication process.
Request Your S355JRH Seamless Square Steel Tube Quote With Mill Test Certificate
Share your project specifications, steel grades, and quantity to receive a detailed quotation with material certification and delivery schedule.
Contact:
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
