Description
Factory-Direct S355 Rectangular Steel Tube — every heat tested in-house before shipment, eliminating the yield-strength surprises that strand containers at European ports.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S355 Rectangular Steel Tube |
| Product Type | Rectangular Steel Tube (RHS) |
| Steel Grade | S355, S235, S275, Gr.B, STK400 |
| Standard | EN 10210, ASTM A500, ASTM A53, GB/T 3091 |
| Section Shape | Rectangular |
| Size Range | 15mm×20mm – 700mm×800mm |
| Wall Thickness | 1–30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | Welded (ERW) / Seamless |
| Surface Treatment | Black Painted / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures / Construction frames / Curtain walls / Building structures / Support tubes / Machinery frames |
| MOQ | 10 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Industrial plant frames, pipe rack supports, modular steel structures |
| Construction Companies | High-rise building columns, curtain wall mullions, bridge handrails |
| Machinery Manufacturers | Conveyor frames, hydraulic support structures, equipment bases |
| Infrastructure Developers | Sound barrier posts, solar mounting structures, signage gantries |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a 30mm wall S355 rectangular steel tube means the difference between passing load calculation and failing third-party inspection.
When EPC contractors price a steel structure, they calculate tonnage from theoretical weight. If the actual wall runs negative beyond tolerance, the structural engineer’s load table no longer matches what arrives on site — and the inspector flags the entire batch. I have seen containers held at Rotterdam because the mill cert said S355JR but SGS re-check showed yield below the EN 10219 threshold [NEED_CITE: EN 10219 cold-formed hollow section requirements]. The fix is not renegotiation; it is re-rolling, re-shipping, and a three-week delay on a crane-dependent schedule. Every EN 10210 S355 rectangular steel tube supplier should be able to show you the heat-by-heat lab report before you sign the deposit.
How S355 RHS Matches Structural Frame Load Paths
Rectangular sections carry bending in two axes, which makes the EN 10210 S355 rectangular steel tube the default choice for moment-resisting frames where an I-beam would need lateral bracing. The flat faces also bolt or weld directly to gusset plates without node connectors, cutting fabrication time on conveyor structures and pipe racks. Our ERW line holds the ±1% wall tolerance across the 15×20 to 700×800 mm range, so the same drawing package can call small purlin tubes and heavy column sections from one purchase order.
Engineering Compliance and Surface Selection for Site Conditions
Structural frames designed to EN 1993-1-1 require the steel grade to conform with EN 10219 or EN 10210, and customs in EU member states will ask for the CE mark under EN 10210/10219 at the border [NEED_CITE: CE marking requirements for structural steel hollow sections]. For outdoor or industrial-corrosive sites, hot-dip galvanized S355 RHS removes ongoing maintenance cost; black painted or varnished tubes suit indoor machinery frames where appearance matters more than corrosion resistance. Plain bare tubes are typically specified when the contractor will blast and coat on site after erection.
Steel Grade Hierarchy and ERW Process Fundamentals
S235, S275, and S355 form a yield-strength ladder within the EN system — each step up allows thinner walls for the same load, reducing tonnage and transport cost. S355 is the workhorse for structural frames because it balances weldability with section efficiency. ERW welded tubes suit sizes from 15×20 up to 700×800 mm at lower cost than seamless, while seamless is reserved for high-pressure or heavy-wall applications where the weld seam is a concern. The ±1% tolerance on wall thickness keeps theoretical weight calculations reliable for both the structural engineer and the quantity surveyor.
Hidden Costs When the Mill Cert Does Not Match the Heat
Ordering S355 rectangular steel tube from a supplier who cannot provide heat-traceable mill test certificates shifts the risk entirely onto the buyer. If the yield strength falls short on site re-test, the contractor faces three costs: replacement material at spot price, crane remobilization, and schedule liquidated damages. Certification gaps also trigger customs holds — EU ports routinely detain hollow sections without valid CE EN 10210/10219 documentation [NEED_CITE: EN 10219 cold-formed hollow section requirements]. The expense is never in the tube price; it is in the delay.
Why Procurement Teams Choose Xin Jiyuan for S355 RHS
We run three dedicated production lines with an in-house physical and chemical lab, so every heat is tested before it leaves Jinan — no shipping a container and hoping the port SGS passes it. Our 41 patents include proprietary sharp-corner rectangular tube technology that closes the gap between welded and seamless aesthetics for exposed architectural frames. With 2,800+ specifications in stock, a single order can combine purlin sizes, column sections, and brace tubes without splitting across three suppliers. CE EN 10210/10219, ISO 9001:2015, and SGS/BV third-party inspection are standard, not optional upgrades. We also handle non-standard dimensions and custom lengths, so site cutting waste drops significantly.
Documentation & Compliance
- Mill test certificate documenting S355 chemical composition and yield strength per EN 10219, traceable by heat number
- CE certificate covering EN 10210/EN 10219 for EU customs clearance and project compliance
- ISO 9001:2015 quality management certificate covering the full production and inspection process
- SGS or BV third-party inspection report available for pre-shipment verification at our facility
- Material traceability sheet linking each bundle to its heat number, chemical analysis, and mechanical test results
- Full customs document package: packing list, bill of lading, certificate of origin, and commercial invoice
Packaging, Loading & Delivery
- S355 rectangular tubes bundled with galvanized steel strips and edge protectors to preserve surface treatment during ocean transit
- Galvanized RHS packed with waterproof wraps and timber separators to prevent zinc coating abrasion in container loading
- 6m and 11.8m lengths loaded with professional stowage plans to maximize 20ft and 40ft container payload within road weight limits
- Plain-end tubes capped at both ends to prevent moisture ingress and internal corrosion during storage and shipping
- Each bundle marked with heat number, steel grade S355, size, and length for site identification and inspection traceability
- FOB, CIF, and DDP terms available with door-to-door logistics to 50+ countries including EU, North America, and Southeast Asia
Getting Your S355 RHS Quotation Moving
Send your specification list — sizes, wall thickness, steel grade, quantity, and destination port — and we return a detailed quote within 12 hours, including unit price, delivery schedule, and applicable certification. For non-standard dimensions or custom lengths outside the 15×20 to 700×800 mm range, we provide a feasibility check and lead-time confirmation before you commit.
Start Your S355 Rectangular Steel Tube Inquiry
Submit your drawing list or specification sheet to receive pricing, mill test certificate samples, and container loading plans.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjysteel.com
Email: admin@sdxjysteel.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
