Description
Factory-Direct Bulk Supply — 2,800+ specifications in ready stock with original mill test certificates for every batch of Q195–Q460 and DC51D+Z–DC53D+Z square and rectangular hollow sections.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195-Q460 Carbon Steel Square Rectangular Pipe |
| Product Type | Square and Rectangular Hollow Section |
| Steel Grade | Q195, Q235, Q235B, Q345, Q345B, Q460, SS330, SS400, SS540, DC51D+Z, DC52D+Z, DC53D+Z |
| Standard | ASTM, ISO 9001 |
| Section Shape | Square, Rectangular, Round |
| Wall Thickness | 0.5–200 mm |
| Length | 12 m |
| Technique | Hot Rolled, Cold Rolled |
| Surface Treatment | Hot Rolled, Galvanized (zinc-coated for DC51D+Z, DC52D+Z, DC53D+Z) |
| Tolerance | ±1% |
| Ends | As per customer requirement |
| Processing Services | Bending, Cutting, Welding, Punching, Decoiling |
| Application | Structural frames, construction, machinery, fluid transport, hydraulic systems, gas pipelines, boiler systems |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building columns, structural frames, scaffolding systems, bridge supports |
| Industrial & Energy | Hydraulic pipelines, boiler tubes, gas transport lines, drill operations |
| Machinery & Fabrication | Equipment frames, conveyor structures, machined structural components |
What Negative Wall-Tolerance Errors Cost on a Structural Frame Order
A single batch with excessive negative tolerance can trigger third-party inspection rejection and full-container return.
Engineering procurement teams across the Middle East and Southeast Asia frequently face quality uncertainty when sourcing square and rectangular hollow sections from fragmented suppliers. Wall thickness falls below the specified tolerance band, theoretical weight diverges from actual weight, and SGS or BV复检 flags the entire shipment. The result is customs delays, project schedule slippage, and re-procurement costs that far exceed the original price savings. When sourcing an ASTM hot rolled carbon steel square hollow section supplier, buyers need verified dimensional accuracy backed by original mill test certificates for every heat number.
Matching Hot Rolled and Galvanized Grades to Structural Environments
The Q195–Q460 carbon steel range covers light structural framing through heavy-load bearing applications, while DC51D+Z through DC53D+Z galvanized grades address corrosive environments where zinc coating extends service life without additional painting. Hot rolled square and rectangular tubes in Q345B serve as primary structural members in building frames and industrial platforms, whereas DC53D+Z galvanized sections are specified for outdoor scaffolding, coastal infrastructure, and agricultural structures where moisture and salt exposure demand sustained corrosion resistance. In-house bending and cutting services eliminate secondary fabrication delays at the job site.
Engineering Compliance and Certification Requirements
Structural hollow sections must conform to project-specified standards — ASTM A500 for North American markets, EN 10219 for European cold-formed sections, and EN 10210 for hot-finished profiles. Certification gaps are among the most common causes of customs hold-ups and project compliance failures on international steel procurement. [NEED_CITE: steel grade equivalence between EN and ASTM standards] CE marking under EN 10210/10219 is mandatory for structural steel entering the European Economic Area, while ISO 9001:2015 certification ensures traceable quality management across production batches. Every shipment from Shandong Xin Jiyuan includes original mill test certificates documenting chemical composition and mechanical properties per heat number, with SGS or BV third-party inspection available upon request.
Understanding Carbon Steel Grades and Galvanized Coating Designations
The Q-series (Q195, Q235, Q345, Q460) follows the Chinese GB standard system where the number indicates minimum yield strength in MPa — Q235B delivers approximately 235 MPa yield, suitable for general structural use, while Q460 serves heavy-load applications requiring higher strength-to-weight ratios. The SS-series (SS330, SS400, SS540) aligns with JIS G3101 for general structural rolled steel, with SS400 widely specified across Southeast Asian and Middle Eastern infrastructure projects. DC51D+Z through DC53D+Z are continuous hot-dip galvanized steel grades per EN 10346, where the zinc coating provides sacrificial corrosion protection — DC51D+Z offers standard formability for light structural profiles, while DC53D+Z delivers enhanced drawing quality for complex bending and punching operations. [NEED_CITE: hot-dip galvanized steel coating thickness and corrosion protection standards] Hot rolled production delivers thicker wall sections with consistent mechanical properties across the cross-section, while cold rolled processes achieve tighter dimensional tolerance and smoother surface finish for precision applications.
Hidden Costs of Unverified Steel Procurement
Purchasing square and rectangular hollow sections without verified mill test certificates or third-party inspection creates compounding risks downstream. Material traceability gaps mean failed weld procedures go undetected until structural loading tests — by which point the entire frame may require demolition and replacement. Negative tolerance abuse inflates theoretical invoicing weight while reducing actual load-bearing capacity, creating safety hazards that violate engineering codes. [NEED_CITE: structural steel quality compliance and negative tolerance impact on load capacity] Certification mismatches between purchase orders and delivered documentation trigger customs seizures at destination ports, adding demurrage charges and weeks of delay to project timelines.
Procurement Confidence Through Verified Factory Capability
Shandong Xin Jiyuan operates three production lines with monthly capacity exceeding 20,000 tons, covering 2,800+ specifications in ready stock for immediate dispatch — eliminating the lead-time uncertainty that plagues fragmented sourcing. Every batch ships with original mill test certificates, and our in-house quality lab conducts three-stage inspection before release. CE certification under EN 10210/10219 and ISO 9001:2015 ensure compliance across European, Middle Eastern, and global project specifications. Professional export teams optimize container loading for mixed-specification orders, reducing freight cost per ton while protecting surface treatment integrity during ocean transit. Flexible MOQ from 5 tons supports both trial orders and full-container bulk procurement, with volume discount programs for long-term supply partnerships.
Documentation & Compliance
- Mill test certificate documenting Q195–Q460 chemical composition and mechanical properties per heat number
- CE certificate under EN 10210/10219 for structural hollow sections entering European markets
- ISO 9001:2015 quality management certificate covering full production traceability
- SGS or BV third-party inspection report available for pre-shipment quality verification
- Material traceability by heat number linking each bundle to original slab chemistry and rolling records
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot rolled Q195–Q460 square and rectangular tubes bundled with steel strips and edge protectors to prevent surface damage during transit
- Galvanized DC51D+Z–DC53D+Z sections wrapped with waterproof paper and plastic film to preserve zinc coating integrity during ocean shipping
- Container loading optimized for 12 m standard length and mixed-specification orders to maximize payload per TEU
- In-house bending and cutting services available to deliver pre-fabricated lengths, reducing on-site waste and labor cost
- Heat number and steel grade stenciled on each bundle for site identification and traceability verification
- FOB, CIF, and DDP terms available with professional customs clearance support across 50+ destination countries
Securing Your Bulk Procurement Quote
Submit your specification sheet — including section dimensions, wall thickness, steel grade, quantity, and destination port — to receive a competitive factory-direct quotation with volume pricing, mill test certificate confirmation, and estimated production lead time. Our technical team reviews non-standard or custom bending requirements within 12 hours and provides detailed loading plans for mixed-container orders.
Start Your Bulk Steel Procurement
Send your specifications via email to admin@sdxinjiyuan.com or contact us on WhatsApp at +86 188 5315 7756 to receive your quotation and mill test certificate sample within 12 hours.
Frequently Asked Questions
Q: What steel grade equivalence should I reference when converting between Chinese Q-series and international standards?
A: Q235B corresponds broadly to S235JR per EN 10025 and ASTM A36 in yield strength range, while Q345B aligns with S355JR and ASTM A572 Grade 50. [NEED_CITE: steel grade equivalence chart between GB EN and ASTM standards] We provide detailed equivalence documentation with every quotation to ensure your project engineer can verify compliance.
Q: Can you provide mill test certificates and third-party inspection for customs and project compliance?
A: Every shipment includes original mill test certificates documenting chemical composition and mechanical properties per heat number. SGS and BV third-party inspection is available upon request for pre-shipment verification, ensuring full compliance with destination country import requirements and project specifications.
Q: What is the MOQ for custom sizes and non-standard specifications?
A: Standard specifications are available from 5 tons with ready stock for immediate dispatch. Custom non-standard dimensions and special bending or cutting requirements are accommodated with typical production lead times of 15–25 days depending on order volume and specification complexity.
Q: How do hot rolled and galvanized surface treatments differ for my application environment?
A: Hot rolled Q195–Q460 grades suit indoor structural applications and projects where painting or additional coating will be applied on site. Galvanized DC51D+Z through DC53D+Z grades provide sacrificial zinc coating for outdoor, coastal, or high-humidity environments where corrosion resistance is critical without ongoing maintenance.
Q: How do you optimize container loading for mixed-specification bulk orders?
A: Our export team designs loading plans that maximize payload per container by nesting smaller sections within larger profiles and distributing weight evenly. This approach reduces freight cost per ton and minimizes the number of containers required for multi-specification project orders.
