Description
Factory-Direct Galvanized SHS/RHS Supply — Three in-house ERW lines producing hot dip galvanized square and rectangular steel tubes with original mill test certificates on every heat.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square / Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube (SHS / RHS) |
| Steel Grade | Q195, Q215, Q235, Q345, 10#, 20#, 45#, 16Mn, A53 Grade A/B, St37, St42, St35.4, St52.4, ASTM A500 Grade B/C/D |
| Standard | BS, EN, GB/T 6728, AISI, ASTM A500 / A53, DIN, JIS G3466 |
| Section Shape | Square / Rectangular |
| Size Range | 10 mm – 1000 mm |
| Wall Thickness | 0.6 – 28 mm |
| Length | 1 – 12 m (or customized) |
| Technique | Hot Rolled / Cold Rolled / ERW |
| Surface Treatment | Galvanized (Hot-Dip), Bared, Oiled, Color Paint, 3PE |
| Zinc Coating | 30 – 275 g/m² |
| Ends | Plain / Beveled / Threaded with couplings or sockets; plastic caps and steel rings available |
| Application | Solar power structures, steel structures, construction frames, machinery, scaffolding, bridges, ships, boilers, pressure vessels |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Solar Energy EPC | Mounting structures for ground-mounted PV arrays, inverter support frames, cable trench frameworks |
| Construction & Infrastructure | Building column frames, scaffolding uprights, industrial platform beams, warehouse portal frames |
| Machinery & Equipment | Conveyor support structures, crane boom sections, agricultural machinery frames |
| Marine & Offshore | Ship handrail systems, deck grating supports, bollard post bases |
| Pressure & Process Engineering | Boiler support grids, heat exchanger frames, pipeline sleeper beams |
What Zinc Coating Thickness Decides for a Solar Stent Order
A 42μm reading against a 70μm spec means the entire container fails third-party inspection at destination port.
Solar mounting structures sit exposed to UV, humidity, and saline air for 25 years or more. When buyers receive hot dip galvanized square and rectangular steel tubes with zinc coating below the specified range, the corrosion protection timeline collapses — rust appears within months, not decades. The hidden cost is not just re-galvanizing locally at triple the original expense; it is project delays, structural re-inspection, and lost credibility with the end client. Inconsistent zinc thickness across a single batch often traces back to uncontrolled dipping temperature or inadequate surface preparation at the galvanizing line — defects invisible until a coating thickness gauge is applied. [NEED_CITE: hot dip galvanized coating thickness requirements per ASTM A123]
Matching Solar Mounting and Structural Frame Requirements
Solar EPC contractors need galvanized SHS and RHS that hold dimensional accuracy after cutting, drilling, and welding on-site, while maintaining continuous zinc coverage at every joint and edge. The 10–1000 mm size range and 0.6–28 mm wall thickness spectrum covers everything from lightweight purlin supports to heavy central inverter platform columns. Hot dip galvanizing with zinc coating up to 275 g/m² delivers the corrosion barrier that pre-galvanized or painted alternatives cannot match in coastal or high-humidity solar farm locations. As a Hot Dip Galvanized Square Rectangular Steel Tube Supplier, we produce each batch to order-specific length and end treatment, so field crews receive cut-ready members without secondary processing.
Engineering Compliance and Certification Pathways
Structural frames for solar farms and commercial buildings must comply with load-bearing codes such as EN 1993 or AISC equivalents, which reference material standards like EN 10219 for cold-formed hollow sections or ASTM A500 for welded structural tubing. The steel grade selection — Q235 mapping to S235JR, Q345 to S355JR, or direct ASTM A500 Grade B/C/D procurement — determines whether the design engineer’s calculation holds under audit. CE certification under EN 10210 (hot-finished) or EN 10219 (cold-formed) is mandatory for European project customs clearance; without it, the shipment sits at port regardless of material quality. [NEED_CITE: EN 10219 cold-formed structural hollow section compliance requirements] Third-party inspection by SGS or BV before loading verifies dimensional tolerance, weld integrity, and zinc coating uniformity — a step that separates compliant deliveries from destination-port rejections.
Steel Grade Selection and Galvanizing Process Fundamentals
The Q-series (Q195–Q345) dominates domestic Chinese structural applications, where Q235 offers adequate yield strength for general building frames and Q345 steps up for heavier load paths. International buyers typically specify ASTM A500 Grade B/C/D for North American projects or EN S235/S355 for European work — all producible on the same ERW line with chemistry adjusted per heat. Hot dip galvanizing immerses the formed tube in molten zinc at approximately 450°C, creating a metallurgical bond between zinc and steel that provides cathodic protection far superior to electro-galvanized or spray-coated alternatives. The 30–275 g/m² coating range allows buyers to match protection level to environment: 30–60 g/m² for indoor machinery frames, 100–150 g/m² for standard outdoor construction, and 200–275 g/m² for coastal solar installations. Wall thickness tolerance directly affects theoretical weight calculation — a 3 mm nominal wall at minus tolerance delivers less structural capacity than the drawing assumes, a discrepancy that only emerges during load testing. [NEED_CITE: steel grade equivalence mapping between GB, EN, and ASTM systems]
Hidden Costs of Procuring the Wrong Specification
Ordering a lower zinc coating class than the environment demands leads to premature corrosion at weld zones and cut edges, triggering costly field touch-up or full member replacement. Missing or incomplete mill test certificates cause customs holds in markets requiring EN 10204 3.1 documentation — the cargo clears eventually, but demurrage fees and schedule slippage erase any price savings from the original purchase. Negative tolerance exceeding the standard allowance means the buyer pays for steel that is not there; the structural engineer’s safety margin shrinks without anyone’s knowledge until an independent lab tests the sample. [NEED_CITE: ASTM A500 tolerance limits for structural tubing wall thickness]
Procurement Confidence from a Vertically Integrated Source
Factory-direct pricing flows from owning three ERW production lines with monthly capacity exceeding 20,000 tons — no trading margin sits between the buyer and the mill floor. Every heat passes through an in-house metallurgical laboratory conducting three-stage inspection from raw coil to finished galvanized tube, with original mill test certificates issued per batch. The 2,800+ specification inventory means standard sizes ship immediately while custom non-standard dimensions and lengths are produced within typical lead times. CE certification under EN 10210 and EN 10219, combined with ISO 9001:2015 registration, clears European and international project compliance requirements without documentation gaps. SGS and BV third-party inspections are arranged on request before container sealing, giving buyers independent verification of coating thickness, dimensional accuracy, and weld quality. Professional export teams optimize container loading plans for heavy SHS/RHS bundles, maximizing payload per TEU and reducing per-ton freight cost.
Documentation & Compliance
- Mill test certificate documenting Q235/Q345 or ASTM A500 Grade B chemical composition and mechanical properties per heat number
- CE certificate under EN 10210 for hot-finished or EN 10219 for cold-formed galvanized hollow sections, required for European customs clearance
- ISO 9001:2015 quality management certificate covering the full production and galvanizing process
- SGS or BV third-party inspection report verifying zinc coating thickness, dimensional tolerance, and weld seam quality before shipment
- Material traceability linking each bundle to its heat number, coil origin, and galvanizing batch record
- Complete customs document package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Galvanized SHS/RHS bundles secured with steel strips and edge protectors to prevent zinc coating abrasion during ocean transit
- Plastic end caps fitted on all tube ends to preserve beveled or threaded finishes and block moisture ingress
- Container loading plans optimized for 1–12 m lengths, nesting smaller square tubes inside larger rectangular sections to maximize TEU payload
- Heat number and steel grade stenciled on each bundle tag for site identification and traceability verification
- FOB, CIF, and DDP shipping terms available with professional documentation handling for destination customs clearance
- Custom cut-to-length service available before galvanizing, delivering site-ready members that reduce field waste
Initiating Your Procurement Inquiry
Submit your specification sheet — including section dimensions, wall thickness, steel grade, total tonnage, zinc coating requirement, and destination port — to receive a factory-direct quotation with volume pricing and production timeline. Non-standard dimensions, custom lengths, and specific end treatments are quoted separately with engineering confirmation. Certification and third-party inspection requirements are documented in the proforma invoice before deposit, ensuring full alignment with your project compliance needs.
Frequently Asked Questions
Q: How do Q235 and Q345 map to international steel grade standards?
A: Q235 corresponds to EN S235JR and ASTM A36 in general structural applications, while Q345 maps to EN S355JR and ASTM A572 Grade 50 for higher strength requirements. We provide cross-reference documentation with every mill test certificate.
Q: Can SGS or BV inspect the galvanized tubes before loading?
A: Yes. Third-party inspection by SGS, BV, or Intertek is arranged on request, covering zinc coating thickness measurement, dimensional verification, visual weld inspection, and documentation review before container sealing.
Q: What is the minimum order quantity for custom non-standard sizes?
A: The MOQ is 1 Ton for both standard catalog sizes and custom non-standard dimensions. Custom sizes may require typical production lead times depending on the specification complexity.
Q: How do you ensure zinc coating uniformity on rectangular tubes with sharp corners?
A: Hot dip galvanizing process parameters — including dipping speed, withdrawal angle, and zinc bath temperature — are controlled to ensure continuous coating coverage at corners and edges. Coating thickness is verified by magnetic gauge measurement at multiple points per piece.
Q: What documents are provided for European project customs clearance?
A: Each shipment includes original mill test certificates per EN 10204 3.1, CE certificate under EN 10210 or EN 10219, packing list, bill of lading, and certificate of origin. ISO 9001:2015 certificate is available upon request.
Request Factory-Direct Pricing with Mill Test Certificates
Send your specification requirements — section size, wall thickness, steel grade, quantity, and destination — to receive a detailed quotation with production timeline and certification documentation.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
