Description
Factory-direct SHS production — S355 square steel hollow section pipe manufactured in-house from raw steel billet through cold rolling, welding, and dimensional finishing under a single quality control system.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355 Square Steel Hollow Section Pipe |
| Product Type | Welded Square Steel Tube |
| Steel Grade | S235JR, S355, SS400, Q235B, A36 |
| Standard | BS, EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square |
| Size Range | Customized (40×40 mm and other dimensions available) |
| Wall Thickness | Customized |
| Length | Customized |
| Technique | Cold Rolled / Welded |
| Surface Treatment | Cold Rolled |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures, building structures, machinery manufacturing, home decor, structural frames |
| MOQ | No minimum order quantity restriction |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Building frames, column supports, roof truss systems for warehouses and logistics centers |
| Industrial Facilities | Machinery support structures, equipment platforms, conveyor frame assemblies |
| Infrastructure & EPC | Bridge support frames, solar mounting structures, utility pole bases across Middle East, Southeast Asia, and Africa |
| Architectural & Interior | Decorative structural frames, exposed column systems, home renovation load-bearing elements |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
±1% dimensional tolerance on cold rolled S355 square steel hollow section pipe eliminates fit-up rework at the welding stage.
When buyers outsource fabrication overseas, the most expensive surprises rarely come from the unit price — they come from tubes arriving with wall thickness drifting into negative tolerance beyond acceptable limits. A 40×40 SHS ordered at 3.0mm wall that actually measures 2.6mm will fail third-party inspection at destination port, and the entire container gets stuck in customs while the project schedule burns through standby costs. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements] On structural frame orders where dozens of members must bolt or weld together in sequence, even small dimensional deviations cascade into cumulative misalignment that forces field cutting and re-welding. The S355 square steel hollow section pipe supplier who controls both steel production and fabrication under one roof eliminates the material traceability gap that causes these tolerance disputes.
How S355 SHS Matches Structural Frame and Machinery Support Requirements
The S355 square steel hollow section pipe delivers the yield strength class required for primary load-bearing members in commercial buildings and industrial machinery frames, while the cold rolled surface finish provides the dimensional precision needed for clean welding joints and bolted connections. The ±1% tolerance range ensures that when these hollow sections arrive at the job site, the mating faces of square-to-square connections sit flush without grinding or shimming. For EPC projects spanning Middle East and African markets, the availability of multiple steel grades — S235JR, S355, SS400, Q235B, A36 — means a single S355 square steel hollow section pipe supplier can fulfill specifications written to EN, ASTM, GB, and JIS standards without fragmenting procurement across multiple vendors.
Engineering Compliance and Certification Requirements for Structural Hollow Sections
Structural hollow sections used in load-bearing frames must comply with the dimensional and mechanical requirements of EN 10219 for cold-formed welded structural hollow sections, or EN 10210 for hot-finished equivalents, depending on the project specification. [NEED_CITE: EN 10219 vs EN 10210 structural hollow section standard differences] For projects in the European Union, CE marking per EN 10219/EN 10210 is mandatory for customs clearance and structural approval. North American projects typically require ASTM A500 Grade B or C compliance, while Middle East and African EPC contracts often accept EN or GB equivalents with third-party inspection reports from SGS or BV. The cold rolled technique used in producing these square hollow sections achieves tighter dimensional control than hot rolled alternatives, which matters when connection plates and gussets must align precisely during assembly. Steel grade selection between S235JR and S355 directly affects member sizing — higher yield strength allows thinner walls for the same load capacity, reducing overall structure weight and shipping cost.
Steel Grade Selection and Cold Rolling Process Explained
The S-series steel grades (S235JR, S275, S355) follow the European EN standard system where the number after “S” indicates the minimum yield strength in MPa — S355 delivers higher load-bearing capacity than S235JR, allowing engineers to specify smaller cross-sections for equivalent structural performance. The Q-series (Q235B, Q345B) follows the Chinese GB standard system with similar yield strength progression, while SS400 represents the Japanese JIS G3101 equivalent and A36 covers the American ASTM A36 specification. Cold rolling as a forming technique passes the welded tube through precision rollers at room temperature, which work-hardens the surface and achieves tighter dimensional tolerances than hot rolling — critical for square hollow sections where corner flatness and wall uniformity affect welding fit-up. The welded manufacturing process for these square tubes involves forming flat strip into square profile and welding the longitudinal seam, typically using high-frequency electric resistance welding (ERW) or submerged arc welding (SAW) depending on wall thickness. [NEED_CITE: ERW vs SAW welding methods for structural hollow sections] Surface treatment in cold rolled finish preserves the mill scale-free surface suitable for direct painting or powder coating, while projects in corrosive environments may require galvanizing or additional protective coatings applied after fabrication.
The Hidden Cost of Sourcing Square Hollow Sections Without Verified Material Certification
Purchasing S355 square steel hollow section pipe from traders who source from unverified mills creates a chain of custody gap — when the material arrives at destination without proper mill test certificates documenting chemical composition and mechanical properties, the project engineer cannot approve the material for structural use. [NEED_CITE: material traceability requirements for structural steel in construction projects] Negative tolerance exceeding the specified ±1% range means the actual wall thickness falls below design assumptions, creating structural safety concerns that only surface during third-party inspection — at which point the entire shipment may be rejected or require costly engineering reassessment. Certification gaps also trigger customs delays: EU projects requiring CE EN 10219 compliance cannot clear customs without proper Declaration of Performance documentation, while Middle East and African ports increasingly enforce pre-shipment inspection requirements that demand complete test reports before container release.
Why S355 Square Steel Hollow Section Pipe Buyers Choose Our Vertically Integrated Supply
Our steel production facility operates three dedicated production lines with over 2,800 specifications of raw material inventory, meaning the S355 square steel hollow section pipe you order is manufactured from billet to finished product within a single controlled environment — no third-party material sourcing, no certification chain gaps. The in-house fabrication workshop provides CNC cutting, plasma and flame cutting, drilling, bending, and welding services (MIG/MAG/SAW) directly on the hollow sections we produce, eliminating the coordination delays that occur when material supply and fabrication are split between separate vendors. Every batch undergoes dimensional inspection with caliper measurement of wall thickness before shipment — a practice established after learning that negative tolerance disputes cost more in project delays than the price difference between verified and unverified material. Complete quality documentation packages include welding procedure specifications (WPS), procedure qualification records (PQR), weld maps, dimensional inspection reports, and coating reports — the full package that project engineers and third-party inspectors require for material approval. Our certified welding procedures and qualified welders hold AWS and EN certifications, ensuring that any fabrication work performed on the S355 square steel hollow section pipe meets international quality standards.
Documentation & Compliance
- Mill test certificate documenting S355 chemical composition and mechanical properties per EN 10219, including heat number traceability from raw material to finished hollow section
- CE certificate confirming compliance with EN 10219 for cold-formed welded structural hollow sections, required for EU project customs clearance and structural approval
- ISO 9001 quality management system certificate covering the entire production process from steel making through cold rolling, welding, and dimensional finishing
- SGS or BV third-party inspection report available for projects requiring independent verification of dimensional accuracy, surface quality, and material properties before shipment
- Material traceability documentation linking each S355 square steel hollow section pipe to its specific heat number, chemical composition report, and production batch record
- Complete customs documentation package including packing list, bill of lading, and certificate of origin formatted for destination port requirements in EU, Middle East, Southeast Asia, and African markets
Packaging, Loading & Delivery
- S355 square steel hollow section pipe bundled with steel strips and edge protectors to prevent surface damage to the cold rolled finish during ocean transit and handling at destination port
- Custom length cutting service available before shipment, allowing buyers to receive hollow sections in exact project-required lengths that optimize container loading and reduce on-site cutting waste
- Heat number and steel grade marking applied to each tube end for on-site identification and traceability verification during installation
- Professional container loading plans developed for oversized square hollow sections, maximizing payload per 20ft and 40ft containers while ensuring secure lashing to prevent transit damage
- FOB, CIF, and DDP delivery terms available with complete export documentation, supporting door-to-door logistics for EPC projects across Middle East, Southeast Asia, and African markets
- Surface protection options including anti-rust oil coating for cold rolled finish to prevent corrosion during extended ocean transit periods typical of intercontinental steel shipments
How to Request Quotation and Technical Documentation for Your Project
Submit your project drawings (PDF/DWG format), required steel grades, dimensions, quantities, and destination port to receive a detailed quotation within 24 hours including material cost, fabrication services, surface treatment, packaging, and shipping. Our engineering team will review your shop drawings, confirm dimensional specifications, and provide material optimization recommendations before production begins — ensuring the S355 square steel hollow section pipe you receive matches your structural design requirements exactly.
Get Your S355 SHS Quotation with Full Material Certification
Send your project specifications and required quantities to receive pricing, mill test certificate samples, and production lead time confirmation.
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
Frequently Asked Questions
Q: What is the difference between S355, ASTM A500, and Q345B steel grades for square hollow sections?
A: S355 follows the European EN standard system with minimum yield strength of 355 MPa, ASTM A500 follows the American standard system with Grade B and Grade C options, and Q345B follows the Chinese GB standard system. All three deliver similar structural performance, and our production facility can manufacture square hollow sections to meet any of these specifications based on your project requirements.
Q: Can you provide third-party inspection reports for S355 square steel hollow section pipe?
A: Yes, we arrange SGS or BV third-party inspection for projects requiring independent verification of dimensional accuracy, wall thickness, surface quality, and material properties. The inspection occurs before shipment, and the complete report is included in your documentation package for customs clearance and project approval.
Q: What is the minimum order quantity for custom dimensions of square hollow sections?
A: We have no minimum order quantity restriction for S355 square steel hollow section pipe. Whether you need a single container of standard dimensions or custom-cut lengths for a specific project, we can accommodate your requirements with the same quality control and documentation standards.
Q: How do you ensure wall thickness tolerance meets the ±1% specification?
A: Every batch of S355 square steel hollow section pipe undergoes dimensional inspection with caliper measurement before shipment. Our vertically integrated production from raw steel to finished hollow section allows us to control the entire process and maintain consistent wall thickness within the specified tolerance range.
Q: What surface treatment options are available for square hollow sections in corrosive environments?
A: Standard delivery is cold rolled finish suitable for painting or powder coating. For corrosive environments, we can provide hot-dip galvanizing or additional protective coating services. The surface treatment selection depends on your project’s environmental conditions and design specifications.
