Description
Factory-direct pricing with no middlemen — every hot dip galvanized square steel pipe ships from our Jinan facility with in-house mill test certificates and full CE/ISO traceability.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Galvanized Square Steel Pipe |
| Product Type | Galvanized Square and Rectangular Steel Tube |
| Steel Grade | 20#, S235, S275, A53 Grade B, A500 Grade A/B/C, STK400, SS400, ST42.2, S355JR |
| Standard | ASTM A53, ASTM A500, ASTM A36, ASTM A795, BS1387, EN10255, ISO65, ANSI C80, DIN2440, JIS G3444, GB/T3091, GB/T13793, API 5L, API 5CT |
| Section Shape | Round / Square / Rectangular |
| Outer Diameter | 21.3mm–660mm (1/2″–26″) |
| Wall Thickness | Customized |
| Length | 5.8m / 6m / 11m or customized |
| Technique | Hot-dip Galvanizing |
| Surface Treatment | Hot-dip Galvanized / Pre-Galvanized |
| Pipe Ends | Plain ends / Beveled ends / Threaded ends / Grooved ends |
| Tolerance | ±1% |
| Processing Service | Welding / Punching / Cutting / Bending |
| Package | Plastic caps on both ends + woven bag wrapped + tied in bundle; Standard Seaworthy Packing |
| Application | Oil/gas/water fluid transportation, construction, hydraulic systems, precision machinery parts, power industry, boiler, petrochemical, building industry, municipal water & gas transmission |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Municipal Infrastructure | Water transmission mains, gas distribution networks, drainage culverts |
| EPC & Construction | Steel structure frames, column supports, scaffolding uprights, bridge handrails |
| Machinery Manufacturing | Hydraulic cylinder barrels, conveyor roller frames, precision machined components |
| Petrochemical & Power | Boiler support structures, petrochemical pipe racks, cooling tower frameworks |
What Zinc Coating Thickness Decides on a Municipal Water Project
A failed SGS reinspection at the job site can reject an entire container — regardless of what the mill certificate says.
I watched a batch of galvanized square pipes get torn apart at a municipal water project in Mexico because the zinc coating measured 45 microns instead of the specified 70. The mill test certificate looked fine on paper, but the hot-dip process had been rushed. Now every coating report gets double-checked before a single pipe leaves Jinan. For buyers sourcing a hot dip galvanized square steel pipe, the gap between pre-galvanized and hot-dip galvanized is not just a price difference — it determines whether the pipe survives five years in a corrosive environment or starts rusting at the weld seam within months. Inconsistent coating thickness, unclear steel grade traceability, and missing third-party inspection reports remain the top reasons shipments get held at customs or rejected during project acceptance [NEED_CITE: EN 10219 cold-formed hollow section requirements].
How Hot Dip Galvanizing Matches Corrosive Service Environments
A hot dip galvanized square steel pipe in S235 or S355JR grade, when properly coated through the hot-dip process, forms a metallurgical zinc-iron alloy layer that bonds to the steel substrate — far more durable than electro-galvanized alternatives for outdoor structural and underground applications. For municipal water and gas transmission pipelines, this coating must withstand soil corrosion, moisture, and mechanical damage during installation. Our production lines cover wall thicknesses up to 40mm across 2,800+ specifications, meaning EPC contractors can source both standard and non-standard sizes from a single facility without splitting orders across multiple suppliers.
Structural Compliance and Certification Requirements
Engineering projects in the EU require CE certification under EN 10210/EN 10219 for structural hollow sections, while North American buyers typically reference ASTM A500 or A53 for equivalent applications [NEED_CITE: steel grade equivalence between EN and ASTM standards]. Steel grade selection directly affects load-bearing calculations — S355JR offers higher yield strength than S235, making it suitable for heavier structural frames, while A500 Grade B/C is specified for architectural and mechanical applications. Our in-house physical and chemical laboratory tests every heat number before shipment, and we accept SGS or BV third-party inspection for buyers who require independent verification. Custom end treatments — plain, beveled, threaded, or grooved — allow direct integration with project connection methods without secondary processing at the job site.
Steel Grade Selection and Galvanizing Process Explained
The steel grades offered for this hot dip galvanized square steel pipe span three major international systems: Chinese GB (20#), European EN (S235, S275, S355JR), and American ASTM (A53 Grade B, A500 Grade A/B/C). S-series grades follow EN standards where the number indicates minimum yield strength in MPa — S355JR delivers higher structural capacity than S235, which matters for load-bearing columns and beam assemblies. The hot-dip galvanizing process immerses formed steel tubes in molten zinc at approximately 450°C, creating a coating that typically ranges from 45 to 100+ microns depending on immersion time and steel chemistry. Pre-galvanized tubes, by contrast, are coated from pre-galvanized coil before forming, resulting in thinner zinc at the weld seam — a critical difference for long-term corrosion resistance in outdoor or buried applications. Our proprietary sharp-corner rectangular tube technology, covered by invention patents, produces tight-radius corners that maintain uniform coating thickness even at the most geometrically challenging points.
Hidden Costs of Buying the Wrong Coating or Grade
Specifying pre-galvanized when the project environment demands hot-dip galvanized leads to premature coating failure at weld seams and cut edges — the exact locations most vulnerable to corrosion. Steel grade mismatch creates structural safety risks: substituting S235 for S355JR in a load-bearing frame reduces design capacity without visible warning. Missing or incomplete CE or mill test certificates cause customs delays that can hold up an entire project timeline, while unverified negative tolerance on wall thickness means the pipe weighs less on paper but carries less load in practice [NEED_CITE: cold-formed welded structural hollow section tolerance requirements]. These are not theoretical risks — they are the reasons EPC contractors now require in-house lab reports and third-party inspection before authorizing shipment.
Why Engineering Procurement Teams Source from Xin Jiyuan
Our factory in Jinan operates three dedicated production lines covering square, rectangular, and round steel tubes with wall thicknesses up to 40mm — eliminating the need to coordinate between multiple suppliers for pipes, plates, and structural sections. Every batch passes through our in-house physical and chemical laboratory, producing original mill test certificates that document chemical composition and mechanical properties per the specified standard. We hold 41 invention patents, including proprietary sharp-corner rectangular tube technology that fills specification gaps competitors cannot address. Full international certification — CE EN10210/EN10219, ISO 9001:2015, Singapore FPC, plus SGS and BV verification — ensures customs clearance across EU, North America, and Middle East markets. With exports to 50+ countries and nearly 20 years of international trade experience, our logistics team handles container optimization, professional loading plans, and door-to-door delivery under FOB, CIF, or DDP terms.
Documentation & Compliance
- Mill test certificate documenting S355JR or A500 Grade B chemical composition and mechanical properties per EN 10219 or ASTM A500, traceable by heat number
- CE certificate under EN 10210/EN 10219 for structural hollow sections destined for EU construction and infrastructure projects
- ISO 9001:2015 quality management system certificate covering full production and inspection processes
- SGS or BV third-party inspection report verifying coating thickness, dimensional tolerance, and surface quality before shipment
- Material traceability linking each pipe to its heat number, steel grade, and production batch for project audit compliance
- Complete customs documentation package including packing list, Bill of Lading, and certificate of origin for import clearance
Packaging, Loading & Delivery
- Hot dip galvanized square and rectangular tubes bundled with steel strips and edge protectors to preserve the zinc coating during ocean transit and crane handling
- Plastic caps fitted on both ends of each pipe to prevent moisture ingress and protect threaded or grooved end treatments
- Container loading plans optimized for 5.8m, 6m, and 11m lengths to maximize payload per 20ft or 40ft container, reducing per-ton freight cost
- Custom cutting and length preparation available before galvanizing to match project-specific dimensional requirements
- Heat number and steel grade marked on each pipe bundle for on-site identification and traceability verification
- FOB Jinan/Qingdao, CIF, or DDP delivery options with real-time shipment tracking to ports across EU, North America, Southeast Asia, and the Middle East
Request a Quotation with Mill Test Certificate
Submit your specifications — including steel grade, outer diameter, wall thickness, length, surface treatment preference, and destination port — and receive a detailed quotation within 12 hours, complete with applicable mill test certificate format and certification documentation. For non-standard sizes or custom end treatments, our engineering team will confirm feasibility and lead time before production begins.
Start Your Procurement with Verified Specifications
Send your requirements via email or WhatsApp to receive pricing, coating thickness confirmation, and certification documentation for your hot dip galvanized square steel pipe order.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjysteel.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjysteel.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: What is the difference between hot dip galvanized and pre-galvanized square steel pipes?
A: Hot dip galvanized pipes are immersed in molten zinc after forming, creating a metallurgical zinc-iron alloy coating that covers all surfaces including the weld seam uniformly. Pre-galvanized pipes are formed from already-coated coil, which results in thinner zinc coverage at the weld area. For outdoor structural applications, underground installations, or municipal water projects, hot dip galvanizing provides superior long-term corrosion resistance.
Q: Can you provide steel grade equivalence between EN, ASTM, and GB standards?
A: Yes. We supply steel grades across EN (S235, S275, S355JR), ASTM (A53 Grade B, A500 Grade A/B/C), and GB (20#) systems. Our technical team provides cross-reference documentation confirming chemical composition and mechanical property equivalence for your project specification compliance.
Q: What is the minimum order quantity for custom non-standard sizes?
A: The MOQ is 1 Ton. We cover over 2,800 specifications with wall thicknesses up to 40mm, including custom non-standard dimensions. Our proprietary sharp-corner rectangular tube technology allows production of geometries that standard mills cannot achieve.
Q: Do you provide third-party inspection before shipment?
A: Yes. We accept SGS and BV third-party inspection for quantity, dimensional tolerance, coating thickness, and surface quality verification. Our in-house laboratory also provides original mill test certificates with every shipment, documenting chemical composition and mechanical properties by heat number.
Q: What certifications do your galvanized square steel pipes carry for EU and international markets?
A: Our products hold CE certification under EN 10210/EN 10219 for EU structural applications, ISO 9001:2015 for quality management, Singapore FPC certification, and are verified by SGS and BV. We export to 50+ countries with complete customs documentation including certificate of origin, packing list, and Bill of Lading.
