Description
One-Source Galvanized SHS/RHS Supply — From raw steel coil to hot dipped galvanized finish, all under one roof at our Jinan-based mill and fabrication facility.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195/Q235/Q345 Hot Dipped Galvanized Square and Rectangular Steel Tube |
| Product Type | Square and Rectangular Steel Tube (SHS/RHS) |
| Steel Grade | Q195, Q235, Q345, 10#, 20#, 45#, 16Mn, ASTM A53 (Grade A/B), St37, St42, St35.4, St52.4, Grade B, Grade C, Grade D, Grade 50 |
| Standard | BS EN, GB, AISI, ASTM, DIN, JIS |
| Section Shape | Square / Rectangular |
| Size Range | 10mm–1000mm (outer diameter or side length) |
| Wall Thickness | 0.6–28mm |
| Length | 1–12m (customizable) |
| Technique | ERW (Hot Rolled or Cold Rolled) |
| Surface Treatment | Hot Dipped Galvanized (Zinc Coating 30–275g/m²); also available: Bare, Oiled, Color Paint, 3PE |
| Ends | Plain, Beveled, Threaded with Couplings or Sockets |
| Application | Steel structures, construction frames, general fabrication, manufacturing, trailers, frames, bridge and highway construction, automobile chassis, industrial equipment, machine parts, sign posts, agricultural equipment |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Architecture | Building structural frames, bridge and highway guardrail posts, decorative facade supports |
| Industrial Fabrication | Machinery frames, trailer beds, industrial equipment bases, machine part housings |
| Infrastructure & EPC Projects | Sign post columns, agricultural equipment frames, platform and walkway structures |
Where Zinc Coating Thickness Decides Whether Your Galvanized SHS/RHS Survives the First Year
A 35μm coating on a 60μm spec doesn’t just fail inspection — it fails the project timeline, the budget, and your reputation.
When overseas buyers source Q235 Q345 hot dipped galvanized square rectangular steel tube from China, the distance between order and delivery creates a blind spot. You specify 60μm minimum zinc coating for a West African warehouse frame, but the fabricator subcontracts galvanizing to a third-party bath running at the wrong temperature. The tubes arrive looking fine — until salt spray testing reveals peeling within weeks. [NEED_CITE: hot dip galvanizing coating thickness standards per ISO 1461]
Then there’s the material traceability gap. Your Q345 RHS arrives with a mill test certificate, but the heat number doesn’t match the steel grade on the drawing. The galvanizing layer hides everything — until you cut into it for welding and find the base metal doesn’t hold the specified yield strength. One source, one quality system, one point of accountability — that’s what eliminates these gaps.
How Galvanized SHS/RHS Meets Structural Frame Demands in Corrosive Environments
Hot dipped galvanized square and rectangular steel tubes in Q235 and Q345 grades carry structural loads while the zinc coating provides sacrificial corrosion protection — critical for outdoor construction frames, highway sign posts, and industrial platforms exposed to moisture and chemical atmospheres. The ERW welding process ensures dimensional accuracy across the 10–1000mm size range, while the 30–275g/m² zinc coating range lets engineers match protection level to environment severity. Our vertically integrated production — from steel mill to galvanizing line — means the base metal chemistry and coating thickness are controlled in one facility, not passed between unrelated suppliers.
Engineering Compliance: From Steel Grade Selection to Customs Clearance
Structural projects requiring EN 1090 or AISC compliance demand more than a certificate — they demand traceability from heat number to finished galvanized profile. Q235 maps to S235JR under EN standards; Q345 corresponds to S355JR — but customs authorities in the EU and Middle East increasingly require CE-marked documentation proving the hollow sections meet EN 10219 cold-formed requirements. [NEED_CITE: EN 10219 cold-formed structural hollow sections compliance] The 0.6–28mm wall thickness range covers both light-gauge framing and heavy structural columns, while 1–12m customizable lengths reduce on-site welding and secondary cutting. Third-party inspection by SGS or BV validates coating adhesion, dimensional tolerance, and weld integrity before shipment.
Understanding the Steel Grades and ERW Process Behind Your Galvanized Tubes
Q195 serves light structural and non-load-bearing applications where formability matters more than strength. Q235 is the workhorse grade for general construction frames and fabrication — equivalent to S235JR in the EN system and ASTM A36 in the US standard. Q345 steps up to higher yield strength for load-bearing columns and bridge components, matching S355JR and ASTM A572 Grade 50. The ERW (Electric Resistance Welding) process — using either hot rolled or cold rolled strip as feedstock — produces the longitudinal weld seam that forms the square or rectangular profile. Hot rolled base offers better surface quality for heavier wall thicknesses; cold rolled base provides tighter dimensional tolerance for thin-wall sections. Hot dip galvanizing immerses the finished tube in molten zinc, creating a metallurgical bond that outperforms electroplated or spray-coated alternatives in corrosion resistance and adhesion. [NEED_CITE: steel grade equivalence between GB Q-series and EN S-series standards]
The Hidden Cost of Buying Galvanized Tubes Without Verified Coating and Mill Certification
When a Q235 hot dipped galvanized square rectangular steel tube arrives at site with coating below spec, the rework cost isn’t just the re-galvanizing — it’s the demurrage, the crane rental, the delayed follow-on trades. When the mill test certificate lists a heat number that doesn’t match the physical marking on the tube, the inspector rejects the entire lot. When the wall thickness runs negative beyond tolerance, the structural engineer recalculates the load capacity and redesigns the connection details. [NEED_CITE: dimensional tolerance requirements for structural hollow sections per EN 10219] These aren’t theoretical risks — they’re the daily reality for buyers who source from traders rather than integrated manufacturers.
Why Integrated Mill-to-Galvanizing Production Changes the Procurement Equation
We operate our own steel production facility with three rolling lines and over 2,800 raw material specifications in stock — meaning the Q235 and Q345 strip that becomes your galvanized SHS/RHS starts under our quality system, not a third-party supplier’s. Every batch goes through our in-house理化实验室 for chemical composition and mechanical property verification before it enters the ERW mill. After welding and forming, the tubes move to our galvanizing line where zinc bath temperature, immersion time, and cooling rate are monitored per batch — the same process control that prevents the 35μm coating failures I’ve seen cost buyers tens of thousands in return freight. We hold CE certification for EN 10210 and EN 10219, ISO 9001 quality management, and accept SGS/BV third-party inspection for every shipment. Our professional loading team handles oversized and heavy galvanized bundles with edge protectors to preserve the zinc coating during ocean transit — because a scratched galvanized surface starts corroding before it reaches the job site.
Documentation & Compliance
- Mill Test Certificate documenting Q235/Q345 chemical composition and mechanical properties per GB/T 13793 or EN 10219, with heat number traceability
- CE Certificate confirming compliance with EN 10210 (hot finished) or EN 10219 (cold formed) structural hollow section requirements
- ISO 9001 Quality Management System certificate covering the full production chain from steel making to galvanizing
- SGS or BV Third-Party Inspection Report verifying zinc coating thickness, dimensional tolerance, and weld quality per ISO 1461 and project specifications
- Material Traceability Report linking each bundle to its heat number, steel grade, and galvanizing batch record
- Customs Documentation Package including packing list, bill of lading, and certificate of origin for EU, Middle East, and Southeast Asian port clearance
Packaging, Loading & Delivery
- Galvanized Q235/Q345 SHS/RHS bundled with steel strips and edge protectors to prevent zinc coating damage during handling and ocean transit
- Surface protection maintained through proper stacking separation and moisture-barrier wrapping for 30–275g/m² zinc-coated tubes
- Container loading optimized for 1–12m lengths with weight distribution calculated to maximize 20ft and 40ft GP capacity for 10–500mm section sizes
- Custom cut-to-length service available for 1–12m requirements, reducing on-site waste and welding time for construction frame assembly
- Heat number and steel grade marking on each tube end for on-site identification and inspection traceability
- FOB, CIF, and DDP shipping terms available with full export documentation for door-to-door delivery to project sites
Ready to Source Your Galvanized SHS/RHS? Here’s How We Work
Send us your project drawings or specification sheet — including steel grade (Q235, Q345, or equivalent), section size, wall thickness, length, zinc coating requirement, and destination port. We respond within 24 hours with a detailed quotation covering material, fabrication, galvanizing, packing, and shipping costs, plus a shop drawing timeline and production schedule. Once you approve the drawings and sign the contract, material procurement and production begin immediately — with full QC documentation prepared before shipment.
Get Your Galvanized SHS/RHS Quote with Mill Test Certificate
Submit your specifications, steel grade, and quantity to receive a detailed quotation and complete documentation package within 24 hours.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjystructure.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjystructure.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
