Description
Factory-direct mill supply — Q235B and Q345B hot rolled H-beams and I-beams produced from our own steel mill with full material traceability from slab to finished section.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q235B-Q345 H-Beams / I-Beams |
| Product Type | H-beam / I-beam |
| Steel Grade | Q235B, Q345B |
| Standard | ASTM |
| Section Shape | H / I |
| Flange Width | 50–1000 mm |
| Flange Thickness | 7–20 mm |
| Web Width | 100–588 mm |
| Web Thickness | 5–12 mm |
| Length | 6–12 m |
| Technique | Hot Rolled |
| Tolerance | ±1% |
| Processing Service | Bending, Welding, Decoiling, Punching, Cutting |
| Application | Steel warehouse fabrication, construction structures, industrial building frames, infrastructure projects |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Commercial Construction | Primary building frames for multi-story office buildings and retail complexes |
| Industrial & Manufacturing | Load-bearing columns and roof trusses for factory workshops and production halls |
| Logistics & Warehousing | Portal frame structures for large-span distribution centers and cold storage facilities |
| Infrastructure | Bridge approach structures, platform supports, and conveyor gantries in Belt & Road markets |
What Negative Tolerance Overshoot Really Costs on a Beam Order
A flange thickness reading 8% below nominal can force an entire 300-ton shipment into rejection at the destination port.
When procurement teams source H-beams from traders who aggregate material from multiple rolling mills, there is no single point of accountability for dimensional consistency. I watched a logistics park project in Ho Chi Minh City nearly collapse — not structurally, but financially — because the flange thickness on delivered Q345B sections exceeded negative tolerance by nearly 8%. Third-party inspectors flagged every beam. The general contractor faced re-procurement costs, a six-week schedule delay, and a dispute over who bore the loss. With a Q235B Q345 hot rolled H-beam I-beam supplier that controls both rolling and fabrication under one roof, heat numbers are traceable from slab to finished section, and caliper checks happen before material ever reaches the loading bay [NEED_CITE: dimensional tolerance standards for hot rolled structural sections].
Matching Beam Dimensions to Portal Frame Engineering
Hot rolled Q235B and Q345B H-beams with flange widths spanning 50–1000 mm and web thicknesses from 5–12 mm cover the majority of portal frame specifications used in warehouse and industrial construction. The ±1% tolerance on both flange and web dimensions means connection plates designed to EN 1090 or AISC bolt-hole patterns will land correctly without field reaming. For e-commerce-driven logistics centers requiring clear spans of 30 meters or more, the Q345B grade delivers the yield capacity to carry crane loads and mezzanine dead loads without upsizing member dimensions — a direct cost saving on tonnage and foundation reactions.
Structural Code Compliance and Certification Pathways
Projects targeting EU markets require H-beams fabricated and documented under EN 1090 Execution Class 2 or 3, with mill test certificates conforming to EN 10204 3.1. For North American infrastructure and industrial work, ASTM material specifications and AISC fabrication standards govern acceptance. The Q235B Q345 hot rolled H-beam I-beam supplier must provide chemistry and mechanical data tied to individual heat numbers so that third-party inspectors can verify grade equivalence against the project specification [NEED_CITE: steel grade equivalence mapping between Chinese GB standards and ASTM/EN systems]. Certified welding procedures — whether MIG, MAG, or submerged arc — ensure that any on-site modifications or field splices meet the same quality threshold as factory production.
Understanding Q235B and Q345B in the Hot Rolled Context
Q235B and Q345B belong to the Chinese GB/T 700 and GB/T 1591 grade families, where the numeric prefix indicates the minimum yield strength class in MPa. Q345B offers a higher yield tier than Q235B, making it the preferred selection for primary load-bearing members in multi-story frames and heavy industrial structures where deflection limits are tight. The hot rolling process produces a uniform grain structure through the full cross-section — unlike cold-formed alternatives — which gives these H-beams predictable behavior under cyclic loading and seismic conditions. Flange thicknesses from 7–20 mm and web thicknesses from 5–12 mm allow engineers to select sections that balance bending resistance against self-weight, particularly important when shipping costs are calculated per metric ton to Southeast Asian and African project sites.
The Hidden Price of Unverified Material Sources
Purchasing H-beams through brokers who blend stock from unverified mills creates a chain of risk that only surfaces at the inspection stage. Chemistry reports may not match actual material. Dimensional checks reveal flanges that fall outside tolerance bands, triggering rejection or forced acceptance at a negotiated discount that rarely covers the engineering risk. On projects subject to EN 1090 or AISC audit requirements, missing or inconsistent mill test certificates mean customs holds, re-testing costs at destination, and potential structural safety reviews ordered by the local building authority [NEED_CITE: consequences of non-conforming structural steel in international construction projects]. A Q235B Q345 hot rolled H-beam I-beam supplier operating its own rolling and fabrication lines eliminates these gaps by maintaining a single quality system from raw slab to shipped component.
Why Procurement Teams Choose Our Integrated Mill and Fabrication
Our facility operates three production lines with access to over 2,800 raw material specifications, meaning Q235B and Q345B H-beams are rolled, cut, welded, drilled, and surface-treated within a single controlled environment. Every heat of steel carries a traceable mill test certificate from our own laboratory — not a document sourced from a third-party trader. For projects requiring shop drawing coordination, our engineering team reviews connection details and fabrication sequences before production begins, reducing RFI cycles that typically add weeks to overseas procurement timelines. Welding procedures are qualified to AWS and EN standards, with certified welders performing all structural joints. Complete documentation packages — including WPS, PQR, weld maps, dimensional inspection reports, and coating certificates — travel with every shipment, so destination inspectors have everything needed for sign-off without requesting supplementary data from China.
Documentation & Compliance
- Mill test certificate documenting Q235B and Q345B chemical composition and mechanical properties per GB/T 700 and GB/T 1591, linked to individual heat numbers for full material traceability
- Third-party inspection reports from SGS or BV verifying dimensional accuracy, surface quality, and coating thickness prior to shipment
- Welding procedure specifications (WPS) and procedure qualification records (PQR) for all structural welding performed in our fabrication workshop, qualified to AWS D1.1 and EN ISO 15614
- Dimensional inspection reports confirming flange width, flange thickness, web thickness, and length within ±1% tolerance for every batch
- Complete export documentation package including packing list, bill of lading, and certificate of origin formatted for destination customs clearance
- ISO 9001 quality management system certificate covering the full scope from raw material procurement through fabrication and final delivery
Packaging, Loading & Delivery
- Q235B and Q345B H-beams bundled with high-tensile steel straps at intervals calculated for the 6–12 m length range, preventing shift during ocean transit
- Hot rolled surfaces coated with shop primer or anti-rust oil to protect mill finish during storage and shipping, particularly critical for sections destined for humid tropical ports
- Container loading plans optimized for 20-foot and 40-foot open-top or flat-rack containers, with nested stacking for smaller flange width sections to maximize payload per shipment
- Custom cutting to project-specific lengths available before dispatch, reducing on-site waste and cutting labor at destination
- Each bundle labeled with heat number, steel grade (Q235B or Q345B), section dimensions, and piece count for rapid identification during unloading and inventory check
- FOB, CIF, and DDP shipping terms available with professional oversized cargo handling for beams exceeding standard container dimensions
Ready to Move Your Beam Procurement Forward
Send your project drawings in PDF or DWG format along with required steel grades, section dimensions, quantities, and destination port. Our team responds within 24 hours with a detailed quotation covering material, fabrication, coating, packing, and freight — including a shop drawing timeline and production schedule. Confirm your certification requirements and we will attach the relevant mill test certificates and third-party inspection options to your proposal.
Get Your H-Beam Quotation with Full Material Traceability
Share your specifications, steel grade requirements, and project volume to receive a detailed quotation and mill test certificate preview. Contact us at +86 531 8573 6315 or admin@xjystructure.com, or reach our mobile team via WhatsApp at +86 188 5315 7756.
