Description
Factory-Direct Sharp-Corner Tube Supply — S275JR and S355JR sharp corner square and rectangular steel tubes rolled to EN10210 dimensions with original mill test certificates shipped on every order.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | S275JR S355JR Sharp Corner Square and Rectangular Steel Tube |
| Product Type | Square and Rectangular Steel Tube (Sharp Corner / 90 Degree) |
| Steel Grade | S235JR, S275JR, S355JR, S355J2H, S355J0, ASTM A53 GR.B, Q460, A36, SS400 |
| Standard | EN10210, EN10219, ASTM A53 |
| Section Shape | Square / Rectangular |
| Size Range | 15×15mm–1000×1000mm (Square) / 20×30mm–600×800mm (Rectangular) |
| Wall Thickness | 0.5–50mm |
| Length | 5.8–14m or custom |
| Technique | Hot Rolled Carbon Steel Welded (ERW) |
| Surface Treatment | Galvanized / 3PE / Painted / Coating Oil / Bare |
| Tolerance | ±1% |
| Ends | Plain ends / Cutting / Threading / Beveled / Flange |
| Application | Steel structures / Construction frames / Machinery / Scaffolding / Furniture / Greenhouse / Urban and civil construction / Water and gas pipeline / Low pressure fluid transport |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC & Commercial Construction | Building frames, column sections, moment-resisting portal frames |
| Industrial Facilities | Equipment support structures, mezzanine floors, conveyor gantries |
| Infrastructure & Civil Works | Scaffolding systems, bridge handrails, sound barrier posts |
| Machinery & OEM Manufacturing | Crane booms, hydraulic equipment frames, agricultural machinery chassis |
| Urban & Municipal Projects | Street light poles, signage gantries, greenhouse structural frames |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% dimensional tolerance on a 1000×1000mm S355JR sharp corner square tube is the difference between site-ready fit-up and weeks of rework.
On a Lagos high-rise project I walked through years ago, three containers of rectangular tubes sat in the yard because the corner radius was nowhere near 90 degrees and wall thickness negative tolerance exceeded 12%. Site welders could not achieve proper joint fit-up, and the structural engineer rejected the entire batch. The supplier’s paperwork said EN10210; the actual product said otherwise. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements] When a S355JR sharp corner square and rectangular steel tube supplier cannot guarantee that the tolerance on the certificate matches the steel on the truck, the hidden cost is never the replacement material — it is the crane idle time, the delayed pour, and the reputational damage with the main contractor.
Matching Sharp-Corner Geometry to Moment-Connection Details
True 90-degree sharp corners on S275JR and S355JR sections allow flush bearing contact at moment connections and gusset plate interfaces, eliminating the gap-filling shims that rounded-corner tubes demand. On steel structure frames across Southeast Asia and Middle East EPC sites, this means bolted end-plate connections achieve design clamping force without plastic deformation of the tube face. The S355JR sharp corner square and rectangular steel tube in side lengths up to 1000×1000mm and wall thickness up to 50mm covers everything from light mezzanine framing to heavy equipment support columns, with ERW welding providing consistent seam integrity across the full section.
Structural Compliance and Surface Selection for Corrosive Environments
Load-bearing members designed to EN 1993 require verified section properties — and those properties depend on the actual delivered wall thickness matching the design assumption. [NEED_CITE: EN 1993-1-1 steel structure design verification requirements] For outdoor infrastructure in coastal West Africa or Southeast Asian port zones, hot-dip galvanized surface treatment provides sacrificial zinc protection extending service life without field painting. In buried or submerged applications, 3PE coating offers mechanical damage resistance during backfilling. S355J2H grade with Charpy impact testing at -20°C is specified for low-temperature regions where brittle fracture risk exists, while S235JR remains cost-effective for non-critical interior framing.
Steel Grade Selection: S-Series, Q-Series, and ASTM Equivalence
The S235JR–S275JR–S355JR progression under EN10210 reflects increasing minimum yield strength, directly governing the load capacity of compression members and the deflection limits of beams. Q460 from the Chinese GB system offers comparable performance for domestic-specification projects, while ASTM A53 GR.B and A36 serve North American and Latin American procurement channels. Cross-referencing between these systems requires attention to differences in impact testing requirements and elongation criteria — a S355JR sharp corner square and rectangular steel tube supplier must provide mill test certificates showing both chemical composition and mechanical properties against the specified standard, not a generic equivalence table. [NEED_CITE: steel grade equivalence between EN 10210 and ASTM A500 standards]
ERW welding produces a longitudinal seam with heat-affected zone properties controlled through post-weld heat treatment, making it suitable for structural applications where seamless tubes would be cost-prohibitive. Sharp-corner forming through progressive rolling dies achieves the 90-degree geometry with ±1% tolerance on side dimensions — critical when multiple tube sizes must bolt together at a single node.
The Hidden Cost of Unverified Material on Project Close-Out
Material substitution without notification — receiving S275JR when S355JR was specified — does not surface until structural calculations are audited or load testing reveals deflection beyond design limits. Missing or incomplete mill test certificates trigger customs holds in CE-marking jurisdictions, delaying site delivery by weeks. Negative tolerance beyond the declared ±1% reduces actual section modulus, forcing the structural engineer to either reject the shipment or redesign connections — both options carrying schedule and cost consequences that dwarf the per-ton price difference between verified and unverified supply. [NEED_CITE: EN 10210 dimensional and mechanical property compliance for structural hollow sections]
Procurement Confidence Through Verified Supply Chain Controls
Every S355JR sharp corner square and rectangular steel tube order ships with original mill test certificates documenting heat number traceability from slab to finished section. Our in-house laboratory conducts three-stage inspection covering dimensional verification, weld seam integrity, and mechanical property testing before release. Third-party SGS or BV inspection is available for projects requiring independent verification. With 2,800+ specifications in ready stock and three production lines running simultaneously, standard sizes ship within typical production lead times while custom non-standard dimensions follow engineered tooling schedules. Factory-direct pricing eliminates intermediary markups, with volume discount programs reviewed every six months for recurring procurement partners.
Documentation & Compliance
- Mill test certificate documenting S275JR/S355JR chemical composition and yield strength per EN10210, traceable by heat number
- CE certificate confirming EN10210/EN10219 compliance with FPC factory production control for European market customs clearance
- ISO 9001:2015 quality management certificate covering production process and inspection procedures
- SGS or BV third-party inspection report available before shipment for project-specific verification requirements
- Material traceability documentation linking each bundle to heat number, production date, and test results
- Complete customs document package including packing list, bill of lading, and certificate of origin for destination port clearance
Packaging, Loading & Delivery
- S355JR sharp corner tubes bundled with steel strips and edge protectors to preserve 90-degree corner geometry during ocean transit
- Galvanized surface treatment protected with waterproof wrapping to prevent white rust formation in humid container environments
- Container loading optimized for 5.8–14m lengths with weight distribution calculated to maximize payload within shipping line limits
- Custom cutting to project-specific lengths available, reducing on-site waste and handling for EPC contractors
- Heat number and steel grade stenciled on each bundle for site identification and traceability verification
- FOB, CIF, and DDP terms available with professional export documentation handling for CE/EN compliance markets
Requesting a Project-Specific Quotation
Submit your required specifications — section dimensions, wall thickness, steel grade, total tonnage, and destination port — to receive competitive bulk pricing with volume discounts and confirmed delivery schedules. Non-standard dimensions and custom surface treatment requirements are reviewed by our engineering team within one working day. Mill test certificates and third-party inspection arrangements are confirmed at the quotation stage, ensuring compliance documentation is in place before production begins.
Frequently Asked Questions
Q: What is the difference between S275JR and S355JR for structural applications?
A: S355JR offers higher minimum yield strength than S275JR, allowing reduced section sizes for the same load capacity or increased load capacity for the same section. The choice depends on structural design calculations and project specifications.
Q: Can you provide mill test certificates for customs clearance in CE-marking countries?
A: Yes, every shipment includes original mill test certificates documenting chemical composition and mechanical properties per EN10210/EN10219, along with CE certification and FPC factory production control documentation required for European market entry.
Q: What is the minimum order quantity for non-standard sharp corner dimensions?
A: The minimum order quantity is 1 ton for standard specifications from ready stock. Custom non-standard dimensions follow engineered tooling schedules with typical production lead times confirmed at the quotation stage.
Q: How do you ensure the sharp corner 90-degree geometry meets tolerance requirements?
A: Progressive rolling dies achieve ±1% tolerance on side dimensions with true 90-degree corners. Three-stage inspection in our in-house laboratory verifies dimensional accuracy before shipment, with third-party SGS/BV inspection available for independent verification.
Q: Which surface treatment is suitable for coastal or corrosive environments?
A: Hot-dip galvanized coating provides sacrificial zinc protection for outdoor exposure, while 3PE coating offers mechanical damage resistance for buried or submerged applications. Surface selection depends on the specific environmental conditions and design service life.
Get Your S355JR Sharp Corner Tube Quote with Mill Test Certificates
Send your specifications — section size, wall thickness, steel grade, quantity, and destination — to receive factory-direct pricing and confirmed delivery schedules with full compliance documentation.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
