Description
Factory-Direct Bulk Supply — 2,800+ specifications in ready stock for ASTM A106 Carbon Steel Square and Rectangular Steel Tube, shipped with original mill test certificates and third-party inspection support.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Carbon Steel Square and Rectangular Steel Tube |
| Product Type | Square / Rectangular / Round Steel Tube |
| Steel Grade | Carbon Steel (Q195–Q690) |
| Standard | ASTM A106, ASTM A500, EN 10210/10219, JIS G3466 |
| Section Shape | Square / Rectangular / Round |
| Wall Thickness | 0.7mm – 5.0mm |
| Length | 1–12m or customized |
| Technique | ERW (Hot Rolled Based) |
| Surface Treatment | Galvanized (Z10–Z29), PVC, Black, Color Painting |
| Tolerance | ±1% |
| Hardness | Full Hard |
| Ends | Plain (standard) |
| Application | Steel structures, construction frames, fences, containers, furniture frames, handrails |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding supports, fence posts, corrugated sheet purlins |
| Machinery & Equipment | Engineering supports, conveyor structures, furniture frames, handrails |
| Industrial Fabrication | Container frames, small tool fabrication, pipe making, structural welding |
| Energy & Utilities | Solar panel mounting structures, wind farm access platforms |
What Wall-Thickness Tolerance Costs on a Carbon Steel Square and Rectangular Steel Tube Order
Tight tolerance directly determines whether a structural frame passes load calculation or fails inspection.
When buyers source ASTM A106 Carbon Steel Square and Rectangular Steel Tube from fragmented suppliers, wall thickness often drifts beyond acceptable limits. A batch labeled 2.0mm may arrive at 1.7mm — the theoretical weight looks correct on paper, but the actual load-bearing capacity drops, and third-party inspection flags the discrepancy. In Mexico, I once saw an entire container of seamless tubes rejected at the port because the client’s independent lab found negative tolerance eating into the minimum wall requirement. The cargo sat for two weeks while we arranged replacement. That kind of delay costs more than the tube itself. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
How ERW Hot-Rolled Carbon Steel Tubes Match Structural Frame Requirements
The ERW hot-rolled process produces ASTM A106 Carbon Steel Square and Rectangular Steel Tube with consistent weld integrity and uniform wall distribution across the 0.7mm–5.0mm range. For construction frames and fencing applications, the full-hard condition provides sufficient rigidity without additional heat treatment. The ±1% tolerance ensures that when engineers specify a 3.0mm wall for a load-bearing column, the delivered product meets that requirement — not 2.6mm disguised by rounding. Skin-pass treatment further stabilizes surface flatness, which matters when tubes are welded into visible architectural frames or handrails where appearance and fit-up quality both count.
Engineering Compliance and Certification Requirements for Carbon Steel Hollow Sections
Structural applications demand traceable material properties. ASTM A106 Carbon Steel Square and Rectangular Steel Tube supplied under EN 10210 or EN 10219 standards must carry original mill test certificates documenting chemical composition and mechanical behavior per heat number. For projects entering the European market, Lloyd’s CE certification under EN 10210/10219 is often a customs prerequisite — missing paperwork means cargo held at port, regardless of product quality. In corrosion-prone environments, galvanized coating from Z10 to Z29 extends service life without sacrificing weldability. Custom lengths up to 12m reduce on-site cutting waste, while plain ends allow direct butt-welding or mechanical coupling per project specification. [NEED_CITE: ASTM A500 structural tubing certification requirements for North American construction]
Understanding Carbon Steel Grades and ERW Welding Process for Hollow Sections
The Q195–Q690 carbon steel grade range covers everything from light-duty furniture frames (Q195/Q215) to heavy structural columns (Q355/Q460). Higher grade numbers indicate increased yield strength, allowing thinner walls to carry equivalent loads — but only if tolerance is controlled. The ERW hot-rolled process forms the tube from hot-rolled coil, then welds the seam under pressure. Unlike seamless manufacturing, ERW offers tighter dimensional consistency at lower cost for non-pressure applications. Surface treatment choice depends on environment: black finish suits indoor structural use, hot-dip galvanizing (Z10–Z29) protects outdoor fencing and scaffolding, while PVC coating or color painting serves architectural applications where appearance matters. Each option preserves the underlying steel grade’s mechanical properties while adding environmental resistance.
Hidden Costs of Sourcing ASTM A106 Carbon Steel Square and Rectangular Steel Tube Without Verified Documentation
Buying tubes without original mill test certificates creates downstream risk. If the steel grade cannot be traced to a specific heat number, structural engineers cannot certify the frame — and the building inspector will not sign off. Negative tolerance beyond ±1% reduces actual weight and load capacity, triggering rework or replacement after delivery. Missing CE or ISO documentation causes customs delays in regulated markets, turning a standard lead time into weeks of demurrage charges. Third-party inspection by SGS or BV before shipment catches these issues at the factory, not at the destination port. [NEED_CITE: steel grade traceability requirements for structural hollow sections]
Why Bulk Buyers Choose Xin Jiyuan for Carbon Steel Square and Rectangular Steel Tube
Factory-direct pricing eliminates trading margins on every container. With 2,800+ specifications in ready stock, urgent orders for standard sizes ship within days, while custom lengths and non-standard dimensions are produced across three simultaneous lines with monthly capacity exceeding 20,000 tons. Every batch carries original mill test certificates, and ISO 9001:2015 production is backed by Lloyd’s CE certification under EN 10210/10219. Flexible MOQ from 1-ton trial orders to full-container bulk supports both new buyer evaluation and long-term project supply. Professional export handling covers documentation, customs clearance, and container loading optimization — critical when shipping 12m tubes alongside shorter cuts in a single consignment.
Documentation & Compliance
- Mill test certificate documenting Q195–Q690 carbon steel chemical composition and mechanical properties per ASTM A106 / EN 10219, traceable by heat number
- Lloyd’s CE certificate under EN 10210/10219 for European market customs clearance and structural compliance
- ISO 9001:2015 quality management certificate covering ERW hot-rolled tube production processes
- SGS or BV third-party inspection report available on request, verifying wall thickness tolerance and surface treatment quality
- Material traceability report linking each bundle to specific heat number and production batch
- Complete customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Carbon steel square and rectangular tubes bundled with steel strips and edge protectors to prevent surface damage during ocean transit
- Galvanized tubes (Z10–Z29) wrapped with waterproof paper and plastic sleeves to preserve zinc coating integrity
- Container loading optimized for mixed-length orders (1–12m), maximizing payload while protecting plain ends from deformation
- Custom cutting to project-specified lengths available, reducing on-site waste and labor costs
- Heat number and steel grade marked on each bundle for site identification and inspection traceability
- FOB/CIF/DDP shipping terms with professional export documentation and real-time tracking support
Request Bulk Quotation for ASTM A106 Carbon Steel Square and Rectangular Steel Tube
Submit your specifications — section shape, wall thickness, length, steel grade, surface treatment, and destination port — to receive competitive factory-direct pricing with volume discount tiers. Mill test certificates and third-party inspection reports are provided with every shipment. Non-standard dimensions and custom lengths are available with typical production lead times.
Start Your Carbon Steel Tube Procurement
Send your requirements via email or WhatsApp to receive a detailed quotation within 12 hours, including FOB/CIF pricing, delivery schedule, and certification documentation.
Contact: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Website: www.sdxinjiyuan.com
Frequently Asked Questions
Q: What steel grades are available for ASTM A106 Carbon Steel Square and Rectangular Steel Tube?
A: Carbon steel grades from Q195 to Q690 are available, covering light-duty to heavy structural applications. Equivalent standards include ASTM A500, EN 10210/10219, and JIS G3466. Each grade is supplied with original mill test certificates documenting chemical composition and mechanical properties.
Q: Can you provide non-standard sizes and custom lengths?
A: Yes. Standard lengths range from 1m to 12m, and custom cutting is available. Wall thickness spans 0.7mm to 5.0mm with ±1% tolerance. Non-standard section dimensions are produced based on technical drawings, with flexible MOQ starting from 1 ton for trial orders.
Q: What surface treatment options are available for different environments?
A: Hot-dip galvanized coating (Z10–Z29) suits outdoor and corrosion-prone applications. Black finish is standard for indoor structural use. PVC coating and color painting are available for architectural applications requiring specific appearance. All treatments preserve the underlying steel grade properties.
Q: Do you provide third-party inspection and certification for customs clearance?
A: Yes. SGS and BV third-party inspection is available on request. Lloyd’s CE certification under EN 10210/10219 is provided for European market compliance. ISO 9001:2015 certification covers production quality, and complete customs documentation including certificate of origin is standard with every shipment.
Q: What is the MOQ and how do you handle container loading for mixed orders?
A: MOQ starts from 1 ton, supporting both trial orders and full-container bulk procurement. Professional container loading optimization handles mixed-length orders (1–12m) and multi-specification consolidation, maximizing payload while protecting tube ends and surface treatment during transit.
