Description
Factory-direct flat bars, zero trading gaps — Our own mill with 3 production lines and 2,800+ raw material specs means every Q235B A36 S355 carbon steel flat bar you order rolls from our furnaces, not a trader’s yard.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B / A36 / S235 / S275 / S355 / S400 Carbon Steel Flat Bar |
| Product Type | Carbon Steel Flat Bar |
| Steel Grade | Q235, Q235B, A36, S235, S275, S355, S400 |
| Standard | ASTM A36, EN 10025, GB/T 700, JIS G3101 |
| Technique | Hot Rolled |
| Tolerance | ±1% |
| Lead Time | 8-14 Days |
| Material Type | Non-Alloy Steel |
| Processing Services | Bending, Welding, Decoiling, Punching, Cutting |
| Application | Construction frames, Industrial platforms, Machinery bases, Structural supports, Building infrastructure |
Application Suitability
| Industry | Typical Applications |
|---|---|
| General Contracting & EPC | Building frames, column base plates, bracing members for commercial and industrial structures |
| Steel Fabrication Shops | Connection gussets, stiffener plates, weld-on brackets for portal frames and truss assemblies |
| Infrastructure & Civil Works | Bridge walkway supports, retaining wall anchors, foundation embedment plates |
| Industrial Plant Construction | Equipment skid bases, conveyor support legs, mezzanine floor framing |
| Warehouse & Logistics Build | Racking upright braces, door frame lintels, canopy support beams |
Why Material Traceability Decides Whether Your Flat Bar Order Clears Customs
A missing heat number on a flat bar bundle can halt an entire project shipment at the destination port.
When buyers source Q235B A36 S355 carbon steel flat bar from traders rather than integrated mills, the chain of material certification breaks somewhere between the rolling stand and the container door. I have seen S355 flat bars arrive in South America with no mill test certificate linking them to a specific heat — the inspector flagged the entire lot, and three weeks of re-testing ate into the erection schedule. [NEED_CITE: material traceability requirements for structural steel in EN 10204 inspection documents] With our own steel production facility running 3 lines and holding 2,800+ specifications of raw material, every flat bar we ship carries a full chemical and mechanical record from slab to finished section — no third-party sourcing gaps, no guesswork at customs.
Matching Flat Bar Grades to Structural Connection Demands
Non-alloy carbon steel flat bars in Q235B through S355 grades serve as the backbone of bolted and welded connections across construction frames and industrial platforms. The Q235B A36 S355 carbon steel flat bar range covers both Chinese GB and European EN standards in a single order, so an EPC firm building a warehouse in Southeast Asia can specify S275 for main frames and Q235B for secondary bracing — all from one mill, one certification system. Our in-house processing line handles bending, punching, and cutting to drawing dimensions before shipping, which means your site team receives connection plates ready to weld rather than raw stock that needs secondary handling.
Engineering Compliance Across International Standards
Structural flat bars used in load-bearing frames must conform to the design code governing the project — EN 10025 for European-spec work, ASTM A36 for North American and many Middle East tenders, GB/T 700 for domestic Chinese engineering. [NEED_CITE: steel grade equivalence mapping between EN 10025 and ASTM A36] Selecting S355 over S235 raises the yield threshold for heavier load paths, while Q235B remains the cost-efficient choice for non-critical bracing and temporary works. For EU-bound shipments, EN 1090 CE marking documentation and factory production control certificates accompany every Q235B A36 S355 carbon steel flat bar order, ensuring the receiving engineer can sign off without requesting supplementary test reports.
Hot Rolling, Tolerance, and What ±1% Actually Means on Site
Hot rolled flat bars are produced by passing heated slabs through successive roll stands, producing a mill-scale surface suitable for welding and painting without additional preparation. The ±1% dimensional tolerance on thickness and width means a 100 × 10 mm flat bar will measure between 99–101 mm in width — tight enough for CNC plasma cutting nests and drill-line fixtures, yet forgiving enough to avoid rejection over minor gauge variation. [NEED_CITE: dimensional tolerance classes for hot rolled flat steel per EN 10058] Non-alloy composition across all grades in this range keeps weldability straightforward: no pre-heat is required for thicknesses below 30 mm under normal ambient conditions, and standard MIG/MAG or SAW procedures apply. Surface options include hot rolled black (as-rolled with mill scale), oiled for short-term corrosion protection during transit, or primer-painted for projects where immediate site installation is planned.
The Hidden Cost of Ordering Flat Bars Without Verified Certification
Specifying S355 and receiving S275 — or worse, unmarked mild steel relabeled as S355 — does not show up until the structural engineer reviews the test reports or the inspector drills into a plate that fails hardness checks. The cost is never the price difference between grades; it is the demolition of welded assemblies, the re-order lead time, and the schedule penalty on a critical path. [NEED_CITE: consequences of material non-conformance in structural steel construction per EN 1090-2] Flat bars sourced from traders who blend stock from multiple unknown mills create exactly this risk — our vertically integrated process eliminates it by keeping every heat, every certificate, and every bundle under one roof from raw slab to container loading.
Why Project Teams Source Their Flat Bars From Our Mill
Our steel production facility operates 3 dedicated lines producing flat bars across 2,800+ specifications, meaning your S235, S275, and S355 requirements can be consolidated into a single purchase order with unified certification. Every Q235B A36 S355 carbon steel flat bar leaves our workshop with a mill test certificate generated from our own理化 laboratory — not a document forwarded from an unknown upstream supplier. We hold ISO 9001 certification and offer third-party inspection through SGS, BV, or TÜV at any production stage, giving EPC firms the audit trail their quality manuals demand. For EU projects, we supply EN 1090 CE-marked documentation alongside every shipment; for Middle East and African tenders, ASTM and GB standard certificates are prepared in parallel. Our loading team understands that flat bars — especially longer lengths — require precise timber dunnage placement and tensioned band spacing to prevent edge deformation during ocean transit, a lesson learned the hard way on a Chilean shipment years ago.
Documentation & Compliance
- Mill test certificate documenting Q235B, A36, or S355 chemical composition and mechanical properties per EN 10025 or ASTM A36, linked to individual heat numbers
- CE certificate and Declaration of Performance for flat bars supplied under EN 1090 execution class requirements for EU market projects
- ISO 9001 quality management certificate covering the full production chain from hot rolling through final dimensional inspection
- SGS, BV, or TÜV third-party inspection report available at rolling, finishing, or pre-shipment stages upon request
- Full material traceability package connecting each flat bar bundle to its heat number, chemical analysis, and tensile test results
- Export documentation set including commercial invoice, packing list, bill of lading, and certificate of origin formatted for destination customs
Packaging, Loading & Delivery
- Hot rolled Q235B and S355 flat bars bundled with high-tension steel strips and timber dunnage separators to prevent surface scoring and edge deformation during ocean freight
- Oiled or primer-coated flat bars wrapped in waterproof kraft paper at bundle edges to protect the surface treatment from condensation inside sealed containers
- Container loading plans optimized for flat bar length and weight distribution — 20ft containers loaded with cross-dunnage at verified intervals to prevent bottom-layer compression on long voyages
- Custom cut-to-length and punched flat bars packed separately with clear bundle tags showing drawing reference, heat number, and grade to avoid site mixing
- Each bundle marked with steel grade designation (Q235B / S275 / S355 etc.), heat number, dimensions, and purchase order reference for immediate site identification
- FOB, CIF, and DDP shipping terms available with full export documentation and container tracking through to port of discharge
Getting Your Flat Bar Order Moving
Send your project drawings or a specification list covering grade, dimensions, quantities, and destination port — we respond within 24 hours with a detailed quotation including material, processing, coating, packing, and freight costs, along with the mill test certificate format you will receive. If your project requires custom cut lengths, punched holes, or bent profiles, share the shop drawings and we will return a fabrication feasibility assessment with the quote.
Request a Quote with Full Material Certification
Share your flat bar specifications — grade, size, quantity, and destination — to receive pricing, lead time, and mill test certificate details within 24 hours.
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
