What Structural Steel Fabricators Actually Deliver
When industrial project owners and procurement managers search for structural steel fabricators, they need a fabricator with the equipment, welding qualifications, and production capacity to cut, weld, drill, and finish structural steel components to exact tolerances. Jidian Construction Materials Co., Ltd. operates as a full-service structural steel fabricator from its manufacturing base in Xiamen, Fujian, China. The facility holds the China Steel Structure Manufacturing Special Level Qualification—the highest grade in China's fabricator classification—and produces 360,000 tons of steel structures annually. Fabrication covers welded H-section columns and beams, box columns, truss girders, cross-sections, and round tubes using Q345B/Q355B steel. Every component is shop-fabricated to ±2mm tolerance on production lines imported from Germany, Italy, and Japan, then shipped with complete welding documentation for bolted assembly on site.
Fabrication Capabilities and Equipment Lineup
Structural steel fabrication requires specialized equipment for cutting, welding, drilling, and surface treatment. Jidian's fabrication shop includes:
- Cross-column production line: Welds H-section columns and beams from steel plates, producing sections up to 1,500mm web height with automated submerged-arc welding (SAW).
- European longitudinal box production line: Manufactures welded box columns for multi-story buildings and heavy-load structures. Imported from Germany and Italy.
- CNC plasma cutting: Precision plate preparation for base plates, stiffeners, connection plates, and gussets. Cut accuracy within ±1mm.
- Automated SAW welding: Consistent full-penetration welds on primary structural members. SAW delivers deep weld penetration and uniform bead quality across long welds.
- AMADA secondary processing line: Imported from Japan. Drills bolt holes to ±2mm positioning accuracy, ensuring components align during bolted assembly without field reaming.
- Surface preparation: Shot blasting to Sa 2.5 grade (ISO 8501-1) before galvanizing or painting. Removes mill scale and rust for optimal coating adhesion.
This equipment lineup allows Jidian to fabricate the full range of structural steel components—columns, beams, trusses, bracing, base plates, and connection assemblies—under one roof, eliminating the quality variability of multi-supplier sourcing.
Steel Grades and Material Selection for Fabricated Structures
The steel grade determines the structural performance, weldability, and cost of fabricated components. Jidian primarily fabricates with:
| Steel Grade | Yield Strength | Application | Standard |
|---|---|---|---|
| Q345B | 345 MPa | Columns, beams, general structures | GB/T 1591 |
| Q355B | 355 MPa | Updated grade replacing Q345B | GB/T 1591 |
| Q235B | 235 MPa | Secondary members, bracing, purlins | GB/T 700 |
| Q345qC | 345 MPa | Bridge girders, low-temp toughness | GB/T 714 |
Each steel batch arrives with mill certificates documenting chemical composition, mechanical properties, and impact test results. These certificates become part of the material traceability dossier shipped with every order.
Welding Qualifications and NDT Protocols
Welding quality is the single most critical factor in structural steel fabrication. Jidian's welding procedures are qualified to ISO 15614-1, and every welder carries ISO 9606 certification. The non-destructive testing (NDT) protocol for fabricated structural steel includes:
- Ultrasonic testing (UT): 100% of full-penetration butt welds on primary load-bearing members, per GB/T 11345. UT detects internal flaws—porosity, slag inclusion, lack of fusion—that visual inspection cannot identify.
- Radiographic testing (RT): 10–20% spot checks on critical butt welds, depending on structure type. RT provides a permanent film record of weld internal quality.
- Magnetic particle inspection (MT): Applied to all fillet welds at fatigue-critical details. MT detects surface and near-surface cracks.
- Visual inspection: Every weld is visually inspected for bead profile, undercut, overlap, and dimensional accuracy against the welding procedure specification (WPS).
Jidian also holds the Italy Welding Procedure Qualification Certificate, enabling CE-marked structural components per EN 1090. This certification is essential for European projects requiring CE marking.
Fabrication Tolerance and Quality Control
Dimensional accuracy during fabrication directly affects on-site assembly speed and structural integrity. Jidian fabricates to ±2mm tolerance on all critical dimensions—column length, beam span, bolt-hole position, and connection plate alignment. The AMADA secondary processing line from Japan ensures bolt-hole positioning accuracy that eliminates the need for field reaming or enlargement.
Pre-shipment quality control verifies:
- Raw material mill certificates match specified steel grade
- Weld integrity per UT, RT, and MT reports
- Zinc coating thickness ≥275g/m² for galvanized components (ISO 1461)
- Paint thickness per specification (typically 2×75μm epoxy zinc-rich primer + topcoat)
- Dimensional accuracy against shop drawings
- Bolt-hole diameter and position per ISO 10721 connection design
Out-of-tolerance components are reworked before packing. No component ships without passing all QC checks.
Corrosion Protection Systems for Fabricated Steel
Structural steel requires corrosion protection appropriate to the service environment. Jidian offers three systems:
- Hot-dip galvanizing: All primary steel components immersed in molten zinc at 450°C, achieving ≥275g/m² coating per ISO 1461. The zinc alloy bonds into the steel surface—cannot peel like paint. Provides 20+ years of protection in industrial atmospheres and is the standard for workshops, warehouses, and agricultural buildings.
- Epoxy zinc-rich primer + polyurethane topcoat: Two-coat system (2×75μm) for painted structures. Suitable for urban and industrial environments. Provides 15–20 years of protection with periodic maintenance.
- Thermal spray zinc + epoxy sealer + polyurethane topcoat: Three-layer system achieving 30+ years of maintenance-free service in C4/C5 marine environments per ISO 12944. Used for bridges and coastal structures.
Specify your service environment during inquiry. The engineering team selects the appropriate corrosion protection system based on ISO 12944 atmospheric corrosivity categories.
Types of Structures Jidian Fabricates
As a structural steel fabricator, Jidian manufactures components for a range of building types:
- Portal frame industrial workshops: Clear spans 15–36m, eave height up to 12m, crane-ready columns for 5–32 ton overhead cranes. The most common industrial steel structure.
- Multi-span workshops: 2–5 bays, each 15–36m wide, with independent per-bay crane integration. Modular bay spacing allows future expansion.
- Crane steel structure workshops: Columns and runway beams pre-engineered for heavy-duty overhead cranes used in steel mills, equipment assembly, and material handling.
- Warehouses: Portal frame warehouses with 15–36m clear spans for high-bay racking and logistics. Light steel frame warehouses for smaller spans and budget projects.
- Commercial and public buildings: Multi-story steel frames with box columns, H-section beams, and composite floor decks for offices, schools, shopping centers, and stadiums.
- Bridge structures: Modular steel girder and arch bridges with Q345qC/Q370qC bridge steel, 20–80m spans, shipped in 12m container-compatible modules.
Design Code Compliance and Engineering Documentation
Fabricated steel structures must comply with the design code applicable to the project location. Jidian engineers structures to:
- Chinese GB 50009/50017: Load codes and steel structure design codes. Standard for domestic projects and many Belt and Road countries.
- AASHTO LRFD: Load and Resistance Factor Design for US and international bridge projects. HS-20 or HL-93 loading.
- Eurocode EN 1991/1993: Actions on structures and design of steel structures. Required for EU and many international projects.
- British Standards BS 5400: Steel, concrete, and composite bridges. Used in Commonwealth countries.
Specify your project's governing code during inquiry. The engineering team provides stamped structural calculation reports, connection designs, and material specifications compliant with your local building code—free of charge before production.
Packaging, Shipping, and Container Loading
Steel components are bundled with steel straps and fabric-wrapped at ends to protect galvanized surfaces during transport. Small parts—bolts, nuts, washers, brackets, splice plates—go in iron boxes labeled with part numbers. Standard shipments use 40ft OT (open top) or 40ft HQ containers from Xiamen port. Component dimensions are engineered to fit standard container dimensions (12m × 2.35m × 2.39m) where possible, minimizing freight cost. Oversized truss segments ship via OT containers or breakbulk vessels.
Each shipment includes a complete documentation dossier: mill certificates, weld maps, NDT reports (UT/RT/MT), coating thickness records, shop drawings, and structural calculation reports. These documents support building permit applications and authority approvals at your destination.
Cooperation Process: From Fabrication Inquiry to Installation
- Inquiry: Provide building type, dimensions, crane requirements, local wind/snow/seismic data, and applicable design code.
- Design: Structural calculations, 3D models, and assembly drawings within 5–10 working days. Free of charge.
- Quotation: Detailed price breakdown including steel tonnage, fabrication, coating, hardware, and packaging. Within 24 hours of design confirmation.
- Production: 25–45 days from drawing sign-off, depending on complexity. Weekly production photos shared.
- Quality control: UT, RT, MT, coating thickness, dimensional checks. Full documentation compiled.
- Packing and shipping: Steel bundled, small parts in iron boxes, 40ft containers from Xiamen port.
- Installation support: Assembly drawings, connection sequence videos, and on-site engineer supervision for structures above 2,000 m². Remote support for all projects.
Common Risks When Sourcing from Steel Fabricators
- Unverified welding qualifications: Fabricators without ISO 15614-1 procedure qualification or ISO 9606 welder certification may produce welds that fail under load. Always request welding procedure qualification records (PQR) and welder certificates.
- Inadequate NDT coverage: Some fabricators perform visual inspection only. For primary load-bearing welds, 100% UT is the industry standard. Confirm NDT scope and acceptance criteria before ordering.
- Tolerance failures: Poor bolt-hole positioning leads to alignment problems during assembly, requiring field reaming or shimming. Verify that the fabricator uses CNC drilling equipment with ±2mm positioning accuracy.
- Missing documentation: Building permit applications require mill certificates, NDT reports, and structural calculations. Confirm that the fabricator provides a complete documentation dossier with every shipment.
- Coating system under-specification: Painted steel without galvanizing may corrode within 5–10 years in industrial or marine environments. Verify the corrosion protection system matches your service environment per ISO 12944.
FAQ
Q: What is your annual fabrication capacity?
A: 360,000 tons of steel structures per year, supported by China's highest Steel Structure Manufacturing Special Level Qualification. We can produce multiple building sets simultaneously for large-scale procurement programs.
Q: What steel grades do you fabricate with?
A: Primarily Q345B/Q355B welded H-section for columns and beams, Q235B for secondary members, and Q345qC/Q370qC bridge steel per GB/T 714 for bridge projects. Other grades available on request.
Q: What welding certifications do you hold?
A: Welding procedures qualified to ISO 15614-1, welders certified to ISO 9606. We also hold the Italy Welding Procedure Qualification Certificate for CE-marked components per EN 1090.
Q: What NDT do you perform on welded connections?
A: 100% UT on full-penetration butt welds per GB/T 11345, 10–20% RT spot checks on critical welds, and MT on all fillet welds at fatigue-critical details.
Q: What fabrication tolerance can you achieve?
A: ±2mm on critical dimensions including column length, beam span, bolt-hole position, and connection plate alignment. CNC drilling on the AMADA line from Japan ensures positioning accuracy.
Q: Do you provide structural calculations for building permits?
A: Yes. We deliver stamped structural calculation reports, 3D models, and assembly drawings compliant with GB, AASHTO, Eurocode, or BS—free of charge before production.
Q: What corrosion protection systems do you offer?
A: Hot-dip galvanizing (≥275g/m² per ISO 1461), epoxy zinc-rich primer + polyurethane topcoat, or thermal spray zinc system for 30+ year service in C4/C5 marine environments per ISO 12944.
Q: What is the typical delivery time for fabricated steel?
A: 25–45 days from drawing sign-off, depending on project complexity and tonnage. Shipping from Xiamen port depends on destination.
Q: Do you offer on-site installation supervision?
A: Yes. For structures above 2,000 m², we can dispatch qualified engineers to supervise erection. For smaller projects, we provide assembly drawings, connection sequence videos, and remote support.
Q: What payment terms do you accept?
A: T/T (30% deposit, 70% before shipment) or L/C at sight. Alibaba Trade Assurance is supported.
