Description
Factory-Direct Pricing for Q195 Q235 Galvanized Rectangular Steel Tube 1.2-15.7mm — Every batch leaves Jinan with original mill test certificates and zinc coating inspection reports, cutting out trading markups entirely.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Rectangular Steel Tube |
| Product Type | Rectangular Steel Tube |
| Steel Grade | Q195, Q235, Q345, A36, A53, A106, 10#, 20#, 45# |
| Standard | ASTM, CE, RoHS, BIS, SASO, SABS, JIS, ISO9001 |
| Section Shape | Rectangular |
| Wall Thickness | 1.2 – 15.7 mm |
| Length | 6m, 6.4m, 12m |
| Technique | Cold Rolled Based / Welded |
| Surface Treatment | Galvanized (Zinc Coating Z81~Z120) |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Greenhouse structures, Steel structures, Construction frames, Fencing, Making Pipes, Making Corrugated Sheets, Making Container |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Agriculture & Greenhouse | Greenhouse frame purlins, structural columns, ventilation duct supports |
| Construction & Infrastructure | Building frames, load-bearing columns, scaffolding uprights |
| Industrial Fencing | Perimeter fencing posts, security barrier frames |
| Container Manufacturing | Container corner posts, floor support frames, side wall reinforcements |
| Steel Fabrication | Conveyor structures, equipment bases, pipe rack supports |
What Zinc Coating Thickness Actually Costs You on a Greenhouse Build
A 38μm reading instead of the specified 65μm means your greenhouse frame starts rusting before the first growing season ends.
I once watched a full container of rectangular tubes get held at Jebel Ali because the third-party inspector found zinc coating 40% below the purchase order spec. The buyer paid return-freight, re-galvanizing, and two weeks of demurrage — all because the supplier skipped outbound film-thickness抽检. When you source a Galvanized Rectangular Steel Tube for greenhouse structures in humid or coastal zones, the zinc layer is the only thing standing between your frame and red rust. Z81 to Z120 coating weight covers light indoor use through moderate outdoor exposure, but without verified mill certificates and pre-shipment thickness checks, spec sheets become meaningless paper. [NEED_CITE: EN 10219 cold-formed hollow section requirements for surface coating verification]
Matching Wall Thickness and Grade to Greenhouse Span Loads
Greenhouse frames in Southeast Asia and the Middle East face a dual challenge: high humidity accelerates corrosion, while wind-load codes demand structural rigidity from every purlin and column. The 1.2–15.7 mm wall range on this Galvanized Rectangular Steel Tube lets engineers specify thin-wall sections for light-duty crop shelters or thick-wall members for multi-span commercial greenhouses — all within a single procurement order. Q195 and Q235 grades handle standard agricultural spans economically, while Q345 steps in when snow-load or wind-pressure calculations push stress ratios higher. The ±1% tolerance on wall thickness means field cutting and welding stay within fit-up limits, avoiding on-site reaming or forced assembly.
Structural Compliance and Certification Pathways
Greenhouse projects exported to the EU require CE marking under EN 10219 for cold-formed welded structural hollow sections, while Middle East buyers often need SASO or SABS documentation for customs clearance. ASTM A53 and A36 grades serve North American and Gulf-region specifiers who reference American standards in their tender documents. Every heat number is traceable back to the original mill pour, and our in-house lab runs three-stage inspection before any Galvanized Rectangular Steel Tube leaves the warehouse. Third-party SGS or BV inspection is available for buyers who need independent verification before container sealing. [NEED_CITE: steel grade equivalence between Chinese GB and ASTM standards]
Understanding Q-Series Grades and Cold-Rolled Welded Process
Q195 and Q235 are Chinese national standard carbon structural steels where the “Q” denotes yield point, with 195 and 235 representing minimum yield strength in MPa. These grades offer excellent formability for cold-rolling into rectangular profiles and subsequent welding along the longitudinal seam. Q345, the low-alloy high-strength counterpart, provides roughly 50% higher yield capacity for applications where weight-to-strength ratio matters — such as long-span greenhouse rafters or container corner posts. The cold-rolled based technique produces tighter dimensional accuracy and smoother surface finish compared to hot-formed alternatives, which directly benefits the zinc coating adhesion during galvanizing. The welded seam, when properly controlled, delivers structural continuity comparable to seamless sections at significantly lower cost for non-pressure applications.
Hidden Costs of Buying Unverified Galvanized Tubes
Material substitution — receiving Q195 when Q235 was specified — rarely shows up until the frame fails load testing or bends during bolt-up. Zinc coating that measures 38μm instead of the contracted 65μm will not trigger customs rejection, but it will trigger accelerated corrosion claims six months after installation. Missing mill test certificates delay project handover documentation and can void insurance coverage on commercial greenhouse builds. Negative tolerance abuse — where wall thickness consistently sits at the lower limit — reduces theoretical weight per meter, meaning you pay for steel you did not receive. [NEED_CITE: consequences of non-compliant steel coatings in corrosive environments]
Why Project Buyers Return for Repeat Orders
Factory-direct pricing eliminates the 8–12% markup that trading companies add on every ton, and volume discount tiers activate as annual procurement grows beyond trial quantities. Our Jinan warehouse holds 2,800+ specifications in ready stock, so standard-size Galvanized Rectangular Steel Tube orders ship within days rather than waiting for production slots. Every shipment includes original mill test certificates documenting chemical composition and mechanical properties per the ordered standard — no “certificate available upon request” delays. The professional export team optimizes container loading plans to maximize payload within weight limits, and coordinates door-to-door logistics with full customs documentation. CE EN10210/EN10219 and ISO 9001:2015 certifications satisfy project compliance audits, while SGS/BV third-party inspection provides independent quality verification for risk-averse buyers.
Documentation & Compliance
- Mill test certificate documenting Q195/Q235/Q345 chemical composition and mechanical properties per ASTM or GB standards
- CE certificate confirming EN 10219 compliance for cold-formed welded structural hollow sections exported to EU markets
- ISO 9001:2015 quality management certificate covering production lines and inspection procedures
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional tolerance before shipment
- Full material traceability by heat number linking each bundle to its original mill test record
- Export customs documents including packing list, bill of lading, and certificate of origin for destination clearance
Packaging, Loading & Delivery
- Galvanized Rectangular Steel Tube bundles secured with steel strips and edge protectors to prevent zinc coating abrasion during ocean transit
- Seaworthy packaging with waterproof wrapping for 6m and 12m lengths, protecting the Z81–Z120 zinc layer from moisture condensation
- Container loading optimization calculated for rectangular tube nesting efficiency, maximizing tonnage per 20ft or 40ft container
- Plain-end tubes bundled with heat number tags and steel grade markings visible for site identification upon arrival
- FOB, CIF, and DDP shipping terms available, with professional coordination for port customs and inland delivery to project sites
Getting Your Greenhouse Frame Quote Moving
Submit your specification sheet — rectangular dimensions, wall thickness, steel grade, total tonnage, and destination port — and receive a factory-direct quotation within 12 hours. The quote includes zinc coating options, mill test certificate confirmation, and estimated production lead time based on current stock availability. For non-standard sizes or custom lengths outside the 6m/6.4m/12m range, our technical team reviews feasibility and provides a tailored production schedule.
Start Your Galvanized Rectangular Steel Tube Inquiry
Send your requirements via email or WhatsApp to receive pricing, mill certificates, and container loading plans — our export team responds within half a working day.
Contact: admin@sdxinjiyuan.com | WhatsApp: +86 188 5315 7756
