Description
Factory-Direct Q235 Q355 Zinc Coated Plate — Hot rolled carbon steel plates produced on our own mill lines and zinc coated in-house, shipped with full heat-number traceability from slab to finished sheet.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235 Q355 Hot Rolled ZINC Coated Carbon Steel Plate |
| Product Type | Steel Plate |
| Steel Grade | Q235, Q355, A36, S235JR, S355JR, St37-2, SS400, Q195-Q460, SS330-SS540, ST12-ST14, SPHC-E |
| Standard | AISI, ASTM, BS, DIN, GB, JIS |
| Technique | Hot Rolled |
| Thickness | 0.35–200 mm |
| Width | 1000–2500 mm |
| Length | 2000–12000 mm |
| Surface Treatment | Zinc Coated / Black |
| Tolerance | ±1% |
| Processing Service | Bending, Welding, Decoiling, Cutting, Punching |
| Material | Low Carbon Steel |
| Application | Shipbuilding, Construction, Petrochemical, Machinery Manufacturing, Transportation, Building Structures, Fabrication |
| MOQ | 10 Ton |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Building Structures | Steel frame columns, beam web plates, base plates, gusset plates for warehouse and factory buildings |
| Infrastructure & Bridge Engineering | Splice plates, stiffener plates, bearing plates for highway and rail bridge assemblies |
| Shipbuilding & Offshore | Deck plating, bulkhead stiffeners, hatch coaming plates with corrosion-resistant zinc coating |
| Petrochemical & Industrial Plants | Platform grating supports, pipe rack base plates, vessel skirt plates |
| Machinery Manufacturing | Machine base plates, crane boom splice plates, conveyor frame gussets |
Why Zinc Coating Thickness Decides Whether Your Plate Passes Site Inspection
A zinc coated plate that reads 40 µm on site when the spec calls for 80 µm will be rejected — no negotiation, no partial acceptance.
I learned this the hard way on a Middle East shipment years ago: a batch of Q355 plates arrived with zinc coating measured well below the contracted minimum, and the client’s third-party inspector refused the entire lot. The plates came back, we reprocessed them, and the freight loss alone ran into several thousand dollars. Since then, every Q235 Q355 hot rolled zinc coated carbon steel plate we ship is checked against SGS coating-thickness reports before it leaves the workshop. [NEED_CITE: zinc coating thickness testing methods per ASTM B568 and ISO 1461]
Buyers sourcing overseas consistently flag three risks: coating thickness falling below spec, material certificates not matching heat numbers on the plate, and dimensional tolerance drifting beyond ±1% on wide plates. These are not theoretical concerns — they are the exact items that trigger rejection at port or on-site.
Matching Plate Grade and Coating to the Job Site Environment
A Q235 Q355 hot rolled zinc coated carbon steel plate selected for a coastal warehouse in Southeast Asia faces salt-laden air and high humidity — the zinc layer must be thick enough to act as a sacrificial barrier for the design life of the structure. For an inland factory frame where welding and painting follow fabrication, a black hot rolled surface may be more economical and still meet structural requirements. Our engineering team reviews each order’s environment and connection details before recommending zinc coated versus black finish, and we adjust coating class accordingly. Plates destined for bridge stiffeners or ship deck plating go through tighter dimensional checks because fit-up tolerance on site is unforgiving.
Structural Code Compliance and Certification Path
Engineering specifications for steel structures — whether EN 1993 in Europe, AISC 360 in North America, or GB 50017 in China — require documented proof that the plate’s chemical composition and mechanical properties conform to the nominated grade. [NEED_CITE: steel grade equivalence between EN, ASTM, and GB standards for structural carbon steel] A Q235 Q355 hot rolled zinc coated carbon steel plate shipped to the EU must carry CE marking under EN 1090 if it is used as a load-bearing component, while the same plate going to North America needs to meet ASTM A36 or A572 equivalence with supporting mill test certificates. Customs authorities in several markets now request third-party inspection reports at the port of discharge, so having SGS or BV documentation ready before shipment avoids container demurrage.
Steel Grade Selection and Hot Rolling Process Explained
Q235 and Q355 belong to the Chinese GB/T 700 and GB/T 1591 families respectively; Q235 is a mild carbon steel widely used for general fabrication where forming and welding are primary concerns, while Q355 offers higher yield strength for structural members carrying heavier loads. Their European counterparts S235JR and S355JR follow EN 10025, and the American equivalents A36 and A572 Gr.50 follow ASTM specifications — the chemistry and mechanical envelopes overlap closely but are not identical, so grade substitution requires engineering approval. [NEED_CITE: structural steel grade equivalence tables across EN, ASTM, and GB systems]
Hot rolling produces the plate by passing a steel slab through a series of rollers at temperatures above the recrystallization point, which gives the finished plate good ductility and weldability. The zinc coating is then applied to provide corrosion resistance — the thickness of this coating directly determines how long the plate can withstand atmospheric or marine exposure before the base metal begins to corrode. Our hot rolling lines produce plates from 0.35 mm up to 200 mm thickness in widths up to 2500 mm, covering everything from thin gauge sheet for ductwork to heavy plate for bridge bearing assemblies.
The Hidden Cost of Ordering the Wrong Grade or Tolerance
Ordering a plate with incorrect grade documentation may seem like a paperwork issue until the structural engineer refuses to sign off on the erection. A Q235 Q355 hot rolled zinc coated carbon steel plate delivered without traceable heat numbers cannot be verified against the mill certificate, and the entire batch may need to be replaced at the fabricator’s cost. Exceeding the ±1% thickness tolerance on a wide plate means the theoretical weight used for pricing no longer matches the actual weight — the buyer either overpays or receives undersized material that fails load calculations. Coating thickness below spec triggers rework or rejection, and the freight to return and reprocess plates overseas erodes any initial price saving.
Why Buyers Source This Plate From XJY Structure
We operate our own steel production facility with three hot rolling lines and stock over 2,800 specifications of raw material, which means the Q235 Q355 hot rolled zinc coated carbon steel plate you order is produced, coated, inspected, and documented under a single quality system — there is no gap between material supplier and fabricator. Every plate carries a mill test certificate with full heat-number traceability back to the slab, and we welcome SGS or BV third-party inspection at any stage before shipment. Our engineering team provides shop drawing review and material optimization before production begins, reducing the risk of fabrication errors on site. We hold ISO 9001 certification and can supply CE-marked plates for European projects with EN 1090 compliance documentation. For oversized or heavy plates, our loading team plans container stowage and lashing to prevent edge damage and coating abrasion during ocean transit.
Documentation & Compliance
- Mill test certificate documenting Q235 and Q355 chemical composition, yield strength, and tensile properties per GB/T 700 and GB/T 1591 with full heat-number traceability
- CE certificate and Declaration of Performance for plates supplied to European projects under EN 1090-2 structural fabrication standard
- ISO 9001 quality management system certificate covering hot rolling, zinc coating, and dimensional inspection processes
- SGS or BV third-party inspection report verifying zinc coating thickness, plate dimensions, and surface quality against contract specifications
- Material traceability report linking each plate to its heat number, rolling schedule, and coating batch for project handover documentation
- Export customs documents including packing list, bill of lading, and certificate of origin for destination-country clearance
Packaging, Loading & Delivery
- Q235 and Q355 zinc coated plates bundled with galvanized steel strips and edge protectors to prevent coating damage during handling and ocean transit
- Black hot rolled plates oiled and wrapped in waterproof paper with steel skids for container loading, suitable for 2000–12000 mm length range
- Container stowage planned by our loading team to maximize payload for plates in the 0.35–200 mm thickness range, with wooden separators between layers to avoid friction damage to the zinc coating
- Custom cutting to size available before shipment — plates cut to net shape reduce on-site waste and welding time for fabrication contractors
- Heat number, steel grade, and dimensions marked on each plate surface with indelible paint for site identification and traceability verification
- Shipment terms available as FOB, CIF, or DDP with door-to-door logistics coordination for EPC projects in the Middle East, Southeast Asia, and Africa
Getting Your Quote and Material Certification in Motion
Send us your project drawings or plate schedule specifying steel grade, thickness, width, length, surface treatment preference, and destination port — we respond within 24 hours with a detailed quotation including material, fabrication, coating, packing, and shipping costs. If your project requires third-party inspection or specific certification for customs clearance, confirm this at the inquiry stage so we can arrange SGS or BV scheduling alongside production. For non-standard dimensions or custom cutting to net shape, share your shop drawings and we will return a fabrication and delivery timeline before you commit.
Request Your Q235 Q355 Plate Quotation with Full Mill Test Documentation
Submit your plate schedule or project drawings to receive a detailed quotation, coating thickness commitment, and mill test certificate preview within 24 hours.
Company: 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
