Description
Factory-Direct Galvanized SHS — Every ASTM A500 Gr.B square tube ships with original mill test certificates and third-party verification, cutting out trading markups while ensuring full customs compliance.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square Steel Tube (ASTM A500 / S235–S355 Series) |
| Product Type | Galvanized Square Steel Tube / Square Hollow Section (SHS) |
| Steel Grade | Gr.B, S235, S275, S355, STK400, Q195–Q690 |
| Standard | ASTM A500, ASTM A53, GB/T 3091, EN 10219, EN 10210, JIS G3466 |
| 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 or Seamless |
| Surface Treatment | Galvanized / Black Painting / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures, Construction frames, Curtain wall systems, Support tubes, Building structures, Machinery frames, Scaffolding |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Industrial plant steel frames, pipeline support structures, equipment skid bases |
| Construction Companies | High-rise building column systems, curtain wall sub-frames, scaffolding uprights |
| Machinery Manufacturers | Conveyor system frames, automated equipment bases, crane boom sections |
| Infrastructure Developers | Bridge handrail posts, solar mounting structures, sound barrier supports |
What Zinc Coating Weight Costs You at Customs and on Site
A galvanized square steel tube with insufficient coating thickness fails inspection before it ever reaches the welding bay.
I have watched entire shipments of SHS get held at port because the galvanizing layer measured below the minimum threshold required by the destination country’s building code. The buyer paid twice — once for the product, once for re-galvanizing on arrival. Worse, some suppliers quote “galvanized” without specifying whether it is hot-dip or pre-galvanized, and the coating peels during transit when stacked without edge protection. For a galvanized square steel tube destined for outdoor structural use, coating mass directly determines corrosion resistance lifespan and project acceptance. [NEED_CITE: hot-dip galvanized coating thickness requirements for structural steel]
Matching Section Dimensions to Structural Load Paths
When specifying a galvanized square steel tube for building frames or machinery bases, the outer dimension and wall thickness must align with the load path calculated by the structural engineer. A 100×100×5mm SHS carries a fundamentally different moment capacity than a 100×100×3mm section, even though both fit the same connection plate. Our production lines cover 19×19mm through 800×800mm with wall thickness from 1mm to 30mm, meaning engineers do not need to redesign joints to accommodate catalog limitations. The ±1% dimensional tolerance ensures that gusset plates and base connections fit without on-site grinding or reaming — a detail that saves measurable labor hours on large-scale erection.
Engineering Compliance Across Competing Standard Systems
A single infrastructure project may require ASTM A500 Gr.B for the North American-designed portion and S355 structural hollow sections for the European-spec portion. The galvanized square steel tube must carry the correct certification for each zone, and mixing certificates causes customs holds. EN 10219 cold-formed sections demand different testing protocols than ASTM A500 welded tubes, and the mill test certificate must explicitly reference the governing standard. [NEED_CITE: EN 10219 cold-formed structural hollow section delivery conditions] For projects spanning multiple regulatory jurisdictions, sourcing all SHS from a single factory that holds CE marking under EN 10210/EN 10219 alongside ASTM compliance eliminates the risk of mismatched documentation at the border.
Steel Grade Selection and Welding Considerations
The jump from S235 to S355 represents a meaningful increase in yield capacity for compression members, but it also changes the carbon equivalent and therefore the pre-heat requirements for field welding. Gr.B under ASTM A500 sits in a comparable range to S235JR, making it suitable for light structural frames where extreme load is not a factor. STK400 under JIS G3466 serves the Japanese-spec market for architectural structural tubes. ERW welded production suits the majority of structural SHS applications where internal pressure is absent, while seamless options address specialized mechanical and high-stress structural needs. Hot-dip galvanizing after fabrication provides the most complete corrosion coverage, including inside the hollow section, whereas pre-galvanized strip offers a thinner but more cost-effective coating for indoor or temporary applications.
The Hidden Price of Tolerance Shortcuts
Ordering a galvanized square steel tube at the lowest unit price often means accepting negative tolerance at the edge of — or beyond — the standard’s allowable band. When wall thickness falls below the minimum specified in EN 10219 or ASTM A500, the structural engineer’s load calculations no longer hold, and the building inspector will reject the entire batch. [NEED_CITE: ASTM A500 tolerance requirements for cold-formed structural tubing] The cost of tearing out installed tubes, re-ordering, and delaying the project schedule dwarfs the initial price saving. Certification gaps compound the problem: without a traceable heat number on the mill test certificate, there is no way to prove the steel grade matches the drawing specification, and no amount of verbal assurance will satisfy a rigorous third-party inspector.
Why Project Procurement Teams Source Here
Every galvanized square steel tube leaving our Jinan facility passes through an in-house physical and chemical laboratory before shipment, producing mill test certificates that trace back to the original heat. We hold 41 patented technologies, including proprietary sharp-corner rectangular tube manufacturing that eliminates the rounded-radius gap common in standard ERW production — critical for flush-fit connections in architectural frames. Our 2,800+ specification range means a single purchase order can cover small-bore support tubes and large-section structural columns without splitting orders across multiple vendors. CE certification under EN 10210 and EN 10219, ISO 9001:2015 registration, and Singapore FPC clearance allow direct shipment to EU, Southeast Asian, and Middle Eastern ports without documentary rejection. We export to 50+ countries with professional container loading plans that maximize payload while protecting the galvanized surface from transit damage.
Documentation & Compliance
- Mill test certificate documenting Gr.B chemical composition and mechanical properties per ASTM A500, traceable by heat number
- CE certificate under EN 10210/EN 10219 for hot-finished and cold-formed structural hollow sections entering EU markets
- ISO 9001:2015 quality management certificate covering the full production and inspection workflow
- SGS or BV third-party inspection report verifying dimensional tolerance, coating thickness, and surface quality before loading
- Material traceability report linking each bundle to its heat number, steel grade, and production batch
- Full customs document package including packing list, bill of lading, and certificate of origin for the destination country
Packaging, Loading & Delivery
- Galvanized square steel tubes bundled with high-tensile steel strips and edge protectors to preserve the zinc coating during ocean transit
- Surface protection supplemented with anti-rust oil or waterproof wrapping for bare or black-painted sections on open-deck shipments
- Container loading plans optimized for 5.8m and 6m lengths to maximize payload within standard 20ft and 40ft GP or HC units
- Custom cut-to-length service available for 11.8m and 12m sections, with bundle markings showing heat number, steel grade, and dimensional specification
- Heat number stenciled on each tube end for on-site traceability verification by the project inspector
- FOB, CIF, and DDP shipping terms available to major ports across 50+ countries with real-time shipment tracking
Getting Your Quote and Mill Documentation Ready
Submit your specification sheet — including outer dimension, wall thickness, steel grade, total tonnage, and destination port — and receive a detailed quotation within 12 hours covering unit price, production lead time, applicable certifications, and shipping options. For non-standard dimensions or custom lengths outside the catalog range, our technical team will confirm feasibility and MOQ before you commit. All mill test certificates and third-party inspection reports are prepared before shipment, so your customs clearance proceeds without documentary delay.
Frequently Asked Questions
Q: How do S235/S355 under EN standards map to Gr.B under ASTM A500?
A: S235JR is broadly comparable to ASTM A500 Gr.B in yield strength range, while S355JR/J0/J2 offers higher yield capacity. We supply all listed grades and can provide equivalence documentation for your project engineer’s review.
Q: Can you provide third-party inspection reports for customs clearance?
A: Yes. SGS and BV third-party inspections are available upon request before shipment, covering dimensional checks, coating thickness measurement, and visual surface quality. The inspection report is included in the shipping document package.
Q: Do you accept non-standard sizes for galvanized square steel tubes?
A: We produce custom dimensions beyond the standard catalog range across our 2,800+ specification portfolio. MOQ for non-standard orders is confirmed during quotation based on the specific size and production setup required.
Q: What is the difference between hot-dip galvanized and pre-galvanized surface treatment?
A: Hot-dip galvanizing applies a thicker zinc coating after the tube is formed, providing superior corrosion resistance for outdoor and structural applications. Pre-galvanized tubes are made from galvanized strip before forming, offering a thinner but more economical coating for indoor or non-critical environments.
Q: How are the tubes packed for container shipment?
A: Galvanized square steel tubes are bundled with steel strips and edge protectors to prevent coating damage. Loading plans are optimized by length and dimension to maximize container utilization while ensuring safe transit.
Start Your ASTM A500 Gr.B Galvanized SHS Inquiry
Send your specification list — size, wall thickness, grade, quantity, and destination — to receive a quotation with full mill test certificate and certification documentation within 12 hours.
Contact: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjysteel.com
Website: www.sdxjysteel.com
