Description
Factory-Direct Galvanized SHS Stock — 2,800+ square tube specifications from 19×19mm to 800×800mm shipped in a single container from our Jinan mill.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized ERW Square Steel Tube |
| Product Type | Welded Square Steel Tube |
| Steel Grade | Gr.B / S235 / S275 / S355 / STK400 |
| Standard | ASTM A500 / ASTM A53 / GB/T 3091 / EN 10219 / EN 10210 |
| Section Shape | Square |
| Size Range | 19mm×19mm – 800mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | ERW / Welded (Seamless also available) |
| Surface Treatment | Hot Dipped Galvanized / Black Painting / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Construction structure / Building frames / Curtain wall / Support tubes / Steel structure fabrication |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & EPC | Building frames, column supports, roof trusses for commercial and industrial projects |
| Facade & Curtain Wall | Sharp-corner square tube framing for glass curtain wall systems and architectural cladding |
| Steel Structure Fabrication | Beam-to-column connections, bracing members, platform supports in steel warehouses |
| Infrastructure | Bridge handrails, highway sign gantries, solar panel support structures |
| Machinery & Equipment | Conveyor frames, equipment bases, protective guard structures |
What Zinc Coating Thickness Actually Decides on a Galvanized Frame Order
A 45-micron zinc layer will fail inspection when the contract specifies 80 microns — and the re-galvanizing bill lands on your invoice, not the mill’s.
I learned this the hard way on a Middle East curtain wall shipment. The tubes arrived at Jebel Ali, the client’s inspector pulled a coating gauge, and an entire container was rejected on the spot. Local re-dipping costs were charged back to us. Since that day, every batch of Hot Dipped Galvanized Square Steel Tube leaving our facility goes through the in-house lab for zinc thickness verification before loading. [NEED_CITE: hot dip galvanizing coating thickness requirements per ASTM A123]
Beyond zinc thickness, buyers sourcing Hot Dipped Galvanized Square Steel Tube for structural and facade work face three recurring procurement gaps: standard rectangular tubes with rounded corners that fail architectural aesthetic requirements, off-standard sizes that most mills simply do not produce, and missing CE or EN compliance documents that block EU customs clearance. These are not minor specification issues — they cause project delays, rework, and rejected shipments.
How Wall-Thickness Range Meets Curtain Wall and Structural Load Demands
A Hot Dipped Galvanized Square Steel Tube covering 1mm to 30mm wall thickness serves two distinct engineering functions on the same project site. Thin-wall sections from 1mm to 3mm handle non-load-bearing curtain wall framing and architectural cladding supports where weight reduction matters. Heavy-wall sections from 6mm to 30mm carry primary structural loads in building frames, bridge supports, and industrial platforms. The ±1% tolerance on wall thickness ensures that structural calculations based on section properties remain valid across the full production batch — a critical factor when engineers sign off on load-bearing capacity per EN 1993 or AISC specifications.
Engineering Compliance Across ASTM, EN, and JIS Frameworks
Hot Dipped Galvanized Square Steel Tube produced under ASTM A500 Gr.B, EN 10219 S235/S355, or JIS STK400 must meet dimensional tolerances, chemical composition limits, and mechanical property thresholds defined by each standard. For EU market imports, CE marking per EN 10210 or EN 10219 is mandatory — without it, customs will hold the shipment regardless of physical quality. [NEED_CITE: EN 10219 cold-formed structural hollow section dimensional tolerances] Steel grade equivalence between ASTM, EN, and JIS systems is well documented but frequently misapplied during ordering; specifying Gr.B when the structural drawings call for S355JR creates a material mismatch that inspection will catch at the destination. Hot dipped galvanizing adds corrosion protection suitable for outdoor exposure in coastal and industrial environments, while black painting or varnish options serve indoor applications where zinc is unnecessary.
Steel Grade Selection and ERW Welding Process Explained
The five steel grades offered — Gr.B, S235, S275, S355, and STK400 — represent three distinct international standard systems. ASTM A500 Gr.B is the default specification for North American structural hollow sections. EN 10219 S235, S275, and S355 follow a yield-strength-based designation where the number indicates minimum yield strength in MPa; S355 provides higher load-bearing capacity than S235 for the same cross-section. JIS G3466 STK400 is the Japanese structural tube grade widely specified in Southeast Asian and Middle East projects. [NEED_CITE: steel grade equivalence between EN S355 and ASTM A500 Gr.B] ERW welding produces a longitudinal weld seam by passing high-frequency current through the steel strip edges, creating a bond suitable for structural applications at lower cost than seamless alternatives. Hot dipped galvanizing immerses the finished tube in molten zinc, forming a metallurgical bond that provides uniform coating coverage including corners and weld seams — superior to pre-galvanized (sendzimir) coating for long-term outdoor corrosion resistance.
Hidden Costs When Galvanized Tubes Arrive Without Proper Documentation
Ordering Hot Dipped Galvanized Square Steel Tube based on price alone, without verified mill test certificates and third-party inspection, creates downstream costs that dwarf the initial savings. Material that fails chemical composition or mechanical property requirements at destination inspection triggers rejection, return shipping, or costly local re-certification. Missing CE marks on tubes destined for the EU result in customs holds that delay project timelines by weeks. Coating thickness below contract specification — such as 45 microns when 80 microns was required — forces the buyer to pay for local re-galvanizing at rates significantly higher than the original factory cost. [NEED_CITE: ASTM A123 zinc coating thickness requirements for structural steel]
Procurement Advantages of Direct Mill Supply
Our Jinan production facility manufactures Hot Dipped Galvanized Square Steel Tube across 2,800+ specifications with wall thickness up to 30mm, eliminating the need to source from multiple traders for different sizes on a single project. The patented sharp-corner rectangular tube technology — backed by 41 invention patents — fills a gap in the architectural market where standard rounded-corner tubes cannot meet facade design requirements. Every shipment includes mill test certificates generated from our in-house physical and chemical laboratory, with third-party inspection by SGS or BV available before loading. Full international certifications including ISO 9001:2015, Lloyd’s CE (EN 10210/EN 10219), and Singapore FPC ensure compliance across EU, Middle East, and Southeast Asian markets. Custom non-standard sizes are available with low MOQ of 1 Ton, and professional container loading with anti-damage measures protects both the zinc coating and tube geometry during ocean transit. We export to 50+ countries with complete documentation packages for smooth customs clearance.
Documentation & Compliance
- Mill test certificate documenting Gr.B / S355 / STK400 chemical composition and mechanical properties per ASTM A500 or EN 10219
- CE certificate per EN 10210 and EN 10219 for EU market customs clearance on Hot Dipped Galvanized Square Steel Tube
- ISO 9001:2015 quality management system certificate covering production and testing processes
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional tolerances before shipment
- Material traceability by heat number linking each tube to its production batch and test results
- Complete customs documentation including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot Dipped Galvanized Square Steel Tube bundled with steel strips and edge protectors to preserve zinc coating integrity during ocean transit
- Surface protection maintained through anti-abrasion separators between layers and moisture-resistant wrapping for 6m and 12m lengths
- Container loading optimized for square tube nesting efficiency, maximizing payload per 20ft and 40ft containers for sizes from 19×19mm to 800×800mm
- Custom cutting to project-specific lengths available from standard 5.8m, 6m, 11.8m, and 12m stock
- Heat number and steel grade markings stenciled on each bundle for site identification and traceability
- FOB, CIF, and DDP shipping terms available with professional loading supervision to prevent bending and surface damage
Request a Quotation with Mill Test Certificate
Submit your Hot Dipped Galvanized Square Steel Tube requirements including outer dimensions, wall thickness, steel grade, surface treatment, quantity, and destination port. Our team responds within 12 hours with detailed pricing, production lead time, and available mill test certificates. For non-standard sizes or sharp-corner rectangular tube specifications, custom manufacturing quotes are provided based on your project drawings.
Get Your Galvanized SHS Quote with Full MTC
Send your specifications to admin@sdxjypipe.com or contact via WhatsApp at +86 188 5315 7756 for pricing, certification documents, and delivery schedules on Hot Dipped Galvanized Square Steel Tube orders.
