Frequently Asked·Questions STEEL STRUCTURE FABRICATION FAQ

We routinely fabricate to EN 1090-2 (EXC2 and EXC3), AWS D1.1 and AISC 303 requirements. Chinese GB 50205 acceptance is also available where the project specification calls for it. The governing standard is fixed in the pre-production technical clarification and printed on every inspection record.

Common grades include S235JR, S275JR, S355J2/J0, ASTM A36, A572 Gr.50 and Q355B. Because we operate our own steel mill with 3 production lines and 2,800+ raw-material specifications, heat numbers are traceable from melt to finished component. EN 10204 3.1 mill test certificates are issued as standard; 3.2 third-party certification is available on request.

Default tolerances follow EN 1090-2 essential and functional tolerance tables, or AISC 303 where American standards govern. Tighter project-specific tolerances -- for example bolt-hole position on splice plates or camber on long-span girders -- are agreed in writing before nesting and verified on the assembly jig.

Yes. Production welders hold valid qualifications to AWS D1.1 or ISO 9606-1 covering the positions, processes and material groups used on your components. Certificate copies with welder ID stamps are issued with the documentation package, and each weld on the weld map is linked to the welder who executed it.

MIG/MAG (GMAW, 135/136), submerged arc welding (SAW, 121) for built-up H-sections and box girders, plus SMAW for site-repair-type joints and restricted access details. Process selection is driven by joint type, throat thickness and the applicable qualified WPS.

Always. WPS, supporting PQR and welder qualification records are submitted as a pre-production package. If your consultant requires a project-specific procedure qualification, we run the test coupons and third-party testing before releasing production welding.

Tekla models (.db1 / IFC), DWG and DXF, PDF shop drawings, and NC1/DSTV files for direct CNC feed. A structured BOM in Excel speeds up quotation considerably. If you only have design drawings, our engineering team can develop shop drawings for your approval.

Yes. Every package goes through a constructability review covering connection detailing, weld access, material optimization and lifting-segment split. Comments and RFIs are returned in a single consolidated list so your detailer can revise once instead of repeatedly.

Revisions are logged with a revision number, issue date and affected mark numbers. Superseded drawings are withdrawn from the shop floor the same day. Where a revision affects already-cut material, we report cost and schedule impact before executing any change.

Yes. We sign an NDA before receiving technical documents. Project files are restricted to the assigned engineering and production team and are never used in marketing material without written permission.

Indicatively 25-35 days for 100-300 tons of standard frame components after drawing approval, and 40-55 days for complex trusses or heavy built-up girders. Because raw material comes from our own mill, we usually skip the 2-3 week plate procurement wait that independent fabricators face.

Each member carries a hard-stamped or painted mark number matching the erection drawing and packing list. Main members are bundled with steel strapping and timber dunnage; bolts, plates and small parts go into labelled steel crates or wooden cases. Packing lists include gross/net weight and dimensions per bundle for crane planning on site.

EXW, FOB, CFR and CIF are standard. Containerised, break-bulk and flat-rack shipments are all handled, including out-of-gauge members. Full export documentation -- commercial invoice, packing list, bill of lading and certificate of origin -- is prepared in-house.

100% visual inspection on all welds as a baseline. Ultrasonic testing on full-penetration butt welds and magnetic particle testing on fillet welds are applied at the coverage rate stated in your specification -- commonly 20% or 100% for primary members. Reports are issued by certified Level II operators.

WPS and PQR, welder qualification certificates, weld maps, material test certificates (EN 10204 3.1), dimensional inspection reports, NDT reports, surface preparation and coating DFT records, plus the packing list and mark-number cross-reference. Delivered digitally before shipment and as hard copy with the cargo.

Yes, and we encourage it. SGS, BV, TÜV, Intertek and client-appointed inspectors are welcome for material verification, in-process hold points, pre-coating inspection and final release. An inspection and test plan with clearly defined witness and hold points is agreed at kick-off.

Shot blasting to Sa 2.5 as standard, followed by epoxy zinc-rich primer, intermediate and polyurethane topcoat systems selected per ISO 12944 corrosivity category. Hot-dip galvanizing to ISO 1461 is available for exposed or coastal projects. Wet-film and dry-film thickness are recorded per member.