Description
Direct Factory Supply for Plate Fabrication — Q235 and Q345 carbon steel plates processed in-house from raw slab to finished cut, bent, and welded components with full heat number traceability.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q345 Carbon Steel Plate with Cutting Bending & Welding Services |
| Product Type | Steel Plate |
| Steel Grade | Q195, Q215, Q235, Q345, SS490, SM400, SM490, SPHC |
| Standard | ASTM, BS, DIN, GB, JIS |
| Section Shape | Flat Sheet |
| Size Range | Width 610–1250 mm |
| Technique | Cold Rolled / Hot Rolled Finish |
| Surface Treatment | Coated |
| Tolerance | ±5% |
| Processing Services | CNC laser cutting, bending, welding |
| Application | Boiler plates, construction, heavy-duty fabrication, welding and bending applications |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Industrial Construction | Boiler shells, pressure vessel end caps, structural base plates for factory frames |
| EPC & Infrastructure | Bridge gusset plates, platform deck plates, column base assemblies |
| Heavy Machinery | Machinery frames, crane boom side plates, excavator bucket reinforcement plates |
| Warehouse & Logistics | Mezzanine floor plates, racking base plates, loading dock structural supports |
Why Fragmented Plate Procurement Costs More Than You Think
Outsourced carbon steel plate cutting bending welding services supplier coordination across multiple vendors creates material traceability gaps and welding procedure mismatches.
When a project sources raw plates from one vendor and farms out CNC cutting and welding to another shop, the mill test certificate chain breaks at the handoff point. I have seen entire batches quarantined because the fabricator could not link a heat number back to the original slab chemistry — the plate looked right, the cutting was clean, but the documentation trail was severed. For a carbon steel plate cutting bending welding services supplier operating under EN 1090 or AISC audit requirements, that missing link means the component cannot be certified for structural use. [NEED_CITE: EN 1090 execution class documentation requirements for structural steel components]
Matching Plate Grades to Structural and Pressure Applications
Q235 and Q345 plates cover the majority of general construction and light-to-medium pressure vessel work across Belt & Road markets. Q235 serves as the baseline structural grade for building frames, platform decks, and non-critical welded assemblies where formability matters more than ultimate strength. Q345 steps up for load-bearing columns, crane runway beams, and boiler support structures that demand higher yield capacity. As a carbon steel plate cutting bending welding services supplier, we match the grade to the engineering drawing — not the other way around — and our CNC laser cutting holds ±5% dimensional tolerance across the 610–1250 mm width range, ensuring fit-up accuracy on site without secondary machining.
Engineering Compliance and Certification Requirements
Structural steel plates fabricated for international projects must satisfy both material standards and execution class requirements. Q235 maps broadly to S235JR under EN standards and ASTM A36 in the US system, while Q345 aligns with S355JR and ASTM A572 Grade 50 — but equivalence is not automatic, and customs authorities in the EU and Middle East increasingly demand documented cross-references. [NEED_CITE: steel grade equivalence mapping between GB, EN, and ASTM standards] Coated surface finishes add corrosion protection for industrial environments, and our welding procedures are qualified per AWS and EN standards with certified welders executing every joint. Shop drawing review, material optimization, and fabrication sequencing are handled before the first cut, reducing RFI cycles and preventing costly rework downstream.
Understanding Carbon Steel Plate Grades and Processing Methods
The Q-series grades (Q195 through Q345) follow the Chinese GB system where the “Q” prefix denotes yield point in MPa — Q235 yields at approximately 235 MPa, Q345 at 345 MPa. This differs from the Japanese SM and SS designations (SM400, SM490, SS490) which reference tensile strength ranges, and from the ASTM system that specifies minimum yield in ksi. Hot rolled plates offer better formability for bending operations and are preferred for boiler plates and pressure components, while cold rolled finish delivers tighter surface quality for visible architectural applications. The coated surface treatment option provides baseline corrosion resistance for warehouse and industrial environments where painting or galvanizing is not specified. Tolerance of ±5% across width and thickness is standard for general fabrication; tighter tolerances require explicit specification at inquiry stage. [NEED_CITE: GB 709 hot rolled steel plate dimensional tolerance standards]
The Hidden Cost of Wrong Grade Selection and Missing Documentation
Specifying Q235 when the structural calculation demands Q345 does not show up until load testing or third-party inspection — by then, the plates are already cut, welded, and painted. Replacing them means demolishing completed assemblies, re-ordering material, and absorbing weeks of schedule delay. Conversely, over-specifying Q345 for a non-critical mezzanine deck inflates material cost without adding structural value. The real risk, however, lies in documentation: a plate with correct chemistry but no traceable heat number cannot pass EN 1090 EXC2 or EXC3 audit, regardless of actual material quality. [NEED_CITE: material traceability requirements under EN 1090 structural fabrication standard]
Why Procure Carbon Steel Plates from XJY Structure
We operate our own steel production facility with three production lines and over 2,800 raw material specifications in stock — meaning the plate you order is melted, rolled, cut, bent, and welded under one roof with a single quality system and one point of accountability. Every heat number is verified against our in-house laboratory reports before any sheet leaves Jinan; I personally check chemistry against real spectrometer data because I have watched doctored mill certs get an entire shipment quarantined at a Dubai job site. Our welding procedures are qualified to AWS and EN standards, our welders hold current certifications, and we produce complete documentation packages including WPS, PQR, weld maps, dimensional inspection reports, and coating reports — not upon request, but as standard deliverables with every shipment.
Documentation & Compliance
- Mill Test Certificate documenting Q235/Q345 chemical composition and mechanical properties per GB 709, with full heat number traceability from our own steel mill
- CE certification for structural steel components manufactured under EN 1090 execution class requirements
- ISO 9001 quality management system certificate covering the entire fabrication process from raw plate receipt to final surface treatment
- Third-party inspection reports from SGS or BV available for pre-shipment verification of dimensional accuracy and coating thickness
- Welding procedure specifications (WPS) and procedure qualification records (PQR) per AWS D1.1 or EN ISO 15614 for all welded components
- Complete export documentation package including packing list, bill of lading, and certificate of origin for customs clearance
Packaging, Loading & Delivery
- Q235 and Q345 coated steel plates bundled with steel strips and edge protectors to preserve surface coating during ocean transit
- CNC-cut plates separated by wooden spacers within each bundle to prevent surface scratching and coating damage from friction
- Container loading optimized for 610–1250 mm width plates to maximize 20ft and 40ft GP utilization with weight distribution calculated per voyage route
- Heat number and steel grade stenciled on each plate end and bundle tag for on-site identification and traceability verification
- FOB Jinan/Qingdao, CIF, or DDP delivery available with professional oversized cargo loading plans for heavy plate shipments
- Custom cutting to project-specified lengths before packing reduces on-site waste and secondary cutting costs
Start Your Fabrication Inquiry with Drawings and Specifications
Submit your project drawings in PDF or DWG format along with steel grade requirements, plate dimensions, quantity, and destination port — we respond within 24 hours with a preliminary assessment covering material cost, CNC cutting and welding fabrication charges, surface treatment options, and estimated production schedule. For projects requiring EN 1090 or AISC compliance, confirm the execution class and certification level at inquiry stage so we can align the documentation package accordingly.
Frequently Asked Questions
Q: What is the difference between Q235 and Q345 carbon steel plates for structural use?
A: Q235 is a general-purpose structural grade suitable for building frames, platforms, and non-critical welded assemblies. Q345 offers higher yield strength for load-bearing columns, bridge components, and pressure vessel supports. The choice depends on structural calculation requirements and applicable design codes.
Q: Can you fabricate plates to custom drawings with CNC cutting and welding?
A: Yes. Our fabrication workshop handles CNC laser cutting, bending, and welding per approved shop drawings. We review drawings before production begins, optimize material usage, and provide fabrication sequencing plans for complex assemblies.
Q: What quality documentation is provided with each plate shipment?
A: Every shipment includes Mill Test Certificates with full heat number traceability, WPS and PQR for welded components, dimensional inspection reports, coating thickness reports, and standard export documents. Third-party inspection reports from SGS or BV are available upon request.
Q: How do you handle plate packing and international shipping for oversized components?
A: Plates are bundled with steel strips and edge protectors, separated by wooden spacers to protect coated surfaces. We prepare professional loading plans for container and breakbulk shipments, with heat numbers and grade markings stenciled for site identification.
Q: What steel grade equivalents do you offer for international standards?
A: Q235 corresponds broadly to S235JR (EN) and ASTM A36; Q345 aligns with S355JR (EN) and ASTM A572 Grade 50. We provide documented cross-references for customs and engineering approval. Japanese grades SM400, SM490, and SS490 are also available.
Get Your Carbon Steel Plate Fabrication Quote Today
Send your drawings, steel grade specifications, and quantity to receive a detailed quotation including material, CNC cutting, bending, welding, surface treatment, and shipping costs — with mill test certificates and full fabrication documentation included as standard.
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
