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Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Factory Direct

Bulk Supply · No Middlemen · 2,800+ Specifications

Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct

Q235B Q345B Hot Dip Galvanized Round Steel Pipe, ASTM ERW, wall thickness 1–30 mm, length 6 m / 12 m — hot-dip galvanized coating ensures uniform zinc coverage for superior corrosion resistance in greenhouse and outdoor structural environments. ERW welding process delivers cost-efficient production with full-length weld seam integrity, covering Q195 to Q345B grades for light-duty to heavy structural applications. Original mill test certificates provided with every shipment, plus SGS/BV third-party inspection available for full customs compliance and quality traceability.

  • ISO 9001:2015
  • CE EN 10210 / 10219
  • FPC Certified
  • Mill Test Certificate
  • SGS / BV On Request
1 t
Trial MOQ
12 h
Quote Reply
3-7 d
Stock Dispatch
100%
With Mill Certs

Send your size list, grade and monthly tonnage -- our export team returns pricing, stock status and documentation plan.

Technical Data

Specification parameters.

Non-standard sizes, grades and surface finishes are produced to order. Confirm exact tolerances with our engineering team before contract.

Technical specification parameters for Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW Factory Direct
Parameter Value
Material Grade Q195 - Q690 · 201 / 304 / 316L · ASTM A500
Standard ASTM A554 / A500 · EN 10219 / 10210 · JIS G3466 · GB
Production Type ERW Welded · Seamless · Hot Dip Galvanized
Size Range 20×20 - 500×500 mm · Wall thickness 0.8 - 20 mm
Length 5.8 m / 6 m / 12 m · Custom cutting available
Surface Finish BA Mirror · No.4 Satin · Pickled · Galvanized
MOQ 1 ton trial order · Full container contract volume
Lead Time Ready stock 3-7 days · Custom 15-25 days
Packing Plastic film + woven bag + steel strapping, seaworthy
Port / Terms FOB Qingdao · CIF / CFR · EXW negotiable

Where It Is Used

Application scenarios.

  • Construction & Structural

    Steel frames, curtain wall supports, canopies and load-bearing hollow sections for commercial projects.

  • Infrastructure Projects

    Highway guardrails, bridge components, transmission towers and municipal engineering works.

  • Machinery & OEM

    Equipment frames, agricultural machinery, conveyor structures and fabricated assemblies.

  • Architecture & Decoration

    Handrails, balustrades, interior fittings and decorative mirror-finish stainless tube.

  • Furniture & Hardware

    Shelving systems, display racks, office furniture tubing and hardware wholesale supply.

  • Energy & Petrochemical

    Fluid conveyance frameworks, platform structures and corrosion-resistant piping supports.

Full Description

Product details.

¥0.45

Q235B Q345B Hot Dip Galvanized Round Steel Pipe, ASTM ERW, wall thickness 1–30 mm, length 6 m / 12 m — hot-dip galvanized coating ensures uniform zinc coverage for superior corrosion resistance in greenhouse and outdoor structural environments. ERW welding process delivers cost-efficient production with full-length weld seam integrity, covering Q195 to Q345B grades for light-duty to heavy structural applications. Original mill test certificates provided with every shipment, plus SGS/BV third-party inspection available for full customs compliance and quality traceability.

Description

Factory-direct pricing with no middlemen — Our 3 production lines in Jinan run hot-dip galvanized round pipes in Q195 through Q345B, shipped with original mill certificates straight from the mill floor to your container.

Technical Specifications

Parameter Value
Designation Q235B / Q345B Galvanized Round Steel Pipe
Product Type Hot-Dip Galvanized Round Steel Pipe
Steel Grade Q195, Q235, Q235B, Q345, Q345B
Standard ASTM, API, CE, RoHS, ISO 9001, JIS
Section Shape Round
Wall Thickness 1–30 mm
Length 6 m / 12 m (customizable)
Technique ERW (Electric Resistance Welded)
Surface Treatment Hot-Dip Galvanized
Tolerance ±1%
Ends Plain / as required
Processing Service Welding, Punching, Cutting, Bending, Decoiling
Application Greenhouse structures, Fluid transport, Gas pipelines, Scaffolding, Agricultural structures, Fence posts
MOQ 1 Ton
Origin Shandong, China

Application Suitability

Industry Typical Applications
Agriculture Greenhouse frame structures, irrigation pipe supports, livestock fencing posts
Infrastructure Fluid and gas pipeline networks, water supply distribution systems
Construction Scaffolding uprights and cross-braces, temporary structural supports
Industrial Conveyor framework, equipment support columns, ventilation duct hangers

What Missing Galvanization Thickness Costs on a Project Acceptance

A thin or uneven zinc coat means field rejection before the first beam goes up.

I watched an entire container of hot-dip galvanized round pipe sit at Jebel Ali port for two weeks because the galvanizing layer failed the customer’s micrometer check on site. The pipes looked fine from a distance, but once the buyer’s inspector pulled out the coating thickness gauge, the whole lot was flagged. That delay cost more in demurrage than the pipes themselves. [NEED_CITE: hot-dip galvanizing coating thickness requirements per ASTM A123]

When you source a Hot Dip Galvanized Round Steel Pipe Supplier without verified process control, you inherit that risk. Coating adhesion failures, bare spots at weld seams, and inconsistent thickness across the batch all trace back to the same root — no in-house lab checking every dip. Third-party inspection reports mean nothing if the supplier cannot show you the original mill test certificate with heat-level traceability.

Hot Dip Galvanized Round Steel Pipe Q235B Q345B cross-section showing zinc coating

How ERW Weld Integrity Meets Greenhouse Structural Demands

Greenhouse frames live in constant humidity — condensation drips, fertilizer runoff, and temperature swings that test any coating system. The Hot Dip Galvanized Round Steel Pipe we produce through ERW welding gives you a continuous longitudinal seam that undergoes full-length weld integrity testing before galvanizing. The zinc bath then covers the entire surface, seam included, creating a metallurgical bond that outlasts painted or electroplated alternatives in wet agricultural environments. Our Q235B and Q345B grades carry the tensile and yield properties needed for snow-load and wind-load calculations typical of commercial greenhouse engineering.

Structural Compliance Across ASTM and EN Frameworks

Engineering specs for greenhouse and scaffolding structures often reference ASTM A500 or EN 10219 depending on the project location. [NEED_CITE: EN 10219 cold-formed hollow section requirements] Our Hot Dip Galvanized Round Steel Pipe conforms to ASTM standards with wall thickness held within ±1% tolerance — critical when your structural engineer calculates load capacity based on exact section modulus. For European buyers, CE certification under EN 10210 and EN 10219 is available, ensuring the pipes clear customs and meet local building code traceability requirements. The 6 m and 12 m standard lengths reduce on-site welding; custom cut-to-length service eliminates field waste.

Steel Grade Selection: Q235B Versus Q345B for Load-Bearing Frames

The Q-series steel grades follow China’s GB/T 700 standard, where the number indicates minimum yield strength in MPa. Q235B delivers adequate strength for most greenhouse framing, fence posts, and light scaffolding — it welds easily, bends cleanly, and costs less per ton. Q345B steps up the yield strength for heavier structural applications like multi-span greenhouse trusses, industrial conveyor supports, or pipeline brackets carrying fluid under pressure. Both grades respond well to hot-dip galvanizing, and our ERW process ensures the weld seam matches the base metal’s corrosion resistance after zinc coating. [NEED_CITE: steel grade equivalence between GB Q-series and ASTM A500]

The Hidden Price of Unverified Coating Thickness

Buying Hot Dip Galvanized Round Steel Pipe without independent verification sounds like a cost saving until the first shipment fails acceptance. Thin zinc coating corrodes faster in humid environments, exposing the base steel within months rather than years. Worse, if the mill test certificate does not match the heat number stamped on each pipe, your project inspector will reject the lot regardless of actual quality. Customs delays from missing CE documentation or incomplete chemical composition reports add weeks to your timeline and thousands in storage fees. [NEED_CITE: consequences of non-compliant galvanized coating in structural applications]

Hot Dip Galvanized Round Steel Pipe surface zinc coating detail

Why Project Buyers Trust Our Mill Direct

We run three production lines simultaneously in Jinan, turning out over 20,000 tons monthly — including dedicated hot-dip galvanizing baths sized for long-length round pipe. Every batch leaves our yard with an original mill test certificate showing chemical composition and mechanical properties tied to the specific heat number. You deal directly with the factory, not a trading company adding markup and hiding the actual production source. Our in-house lab performs three-stage inspection before any third-party SGS or BV audit, so you receive documentation that satisfies both your engineer and your customs broker. For long-term partners, we consolidate round pipe with square tube, plate, and section steel into single container loads — reducing freight cost and simplifying your receiving process.

Documentation & Compliance

  • Mill test certificate documenting Q235B or Q345B chemical composition and mechanical properties per ASTM, with heat number traceability
  • CE certificate under EN 10210 and EN 10219 for European market compliance and customs clearance
  • ISO 9001:2015 quality management certificate covering the full production and galvanizing process
  • SGS or BV third-party inspection report available upon request, covering coating thickness and dimensional tolerance
  • Material traceability report linking each pipe to its original heat number and production date
  • Complete customs document package including packing list, bill of lading, and certificate of origin

Packaging, Loading & Delivery

  • Hot-dip galvanized round pipes bundled with steel strips and edge protectors to prevent zinc coating damage during ocean transit
  • Plain ends capped with plastic protectors to keep moisture and debris out of the bore during storage and shipping
  • Container loading optimized for 6 m and 12 m lengths, maximizing payload per 20ft or 40ft container with weight distribution calculated for crane handling
  • Heat number and steel grade stenciled on each pipe bundle for site identification and inspection traceability
  • Custom cut-to-length service available before galvanizing, reducing field cutting waste on your project site
  • FOB, CIF, and DDP terms supported with professional export documentation and port coordination

Start Your Procurement With Verified Specifications

Submit your required steel grade, wall thickness, length, and destination port — we return a competitive bulk quote within 12 hours, complete with mill test certificate samples and container loading plan. For non-standard dimensions or project-specific certification requirements, our engineering team provides custom solutions with typical production lead times confirmed before you commit.

Get Your Hot Dip Galvanized Round Pipe Quote With Full Mill Certification

Send your specifications to admin@sdxinjiyuan.com or reach us via WhatsApp at +86 188 5315 7756 for pricing, sample arrangement, and third-party inspection coordination.

Frequently Asked Questions

Q: What is the difference between hot-dip galvanized and electro-galvanized steel pipes?

A: Hot-dip galvanizing immerses the steel pipe in molten zinc, creating a metallurgical bond with coating thickness typically much greater than electro-galvanizing. This makes hot-dip galvanized pipe far more suitable for outdoor and corrosive environments like greenhouse structures and outdoor scaffolding, where long-term corrosion resistance matters.

Q: Can you provide mill test certificates and third-party inspection reports?

A: Yes, every shipment includes an original mill test certificate showing chemical composition and mechanical properties tied to the heat number. Third-party inspection through SGS or BV is available upon request to verify coating thickness, dimensional tolerance, and surface quality before loading.

Q: What steel grades are available and how do they compare?

A: We supply Q195, Q235, Q235B, Q345, and Q345B grades. Q235B offers good general-purpose strength for most structural applications, while Q345B provides higher yield strength for heavier load-bearing requirements. Both grades are fully compatible with hot-dip galvanizing and ERW welding processes.

Q: What is the minimum order quantity and can you accept trial orders?

A: Our minimum order quantity is 1 ton, allowing you to place trial orders for quality verification before committing to larger project volumes. We support flexible order quantities from single-ton samples up to full-container bulk shipments.

Q: How do you handle container loading optimization for round pipes?

A: Our export team calculates optimal loading plans based on your pipe dimensions and lengths, maximizing container payload while ensuring weight distribution allows safe crane handling at destination. We consolidate multiple products into single containers when you order mixed steel categories.

Contact Shandong Xin Jiyuan Special Steel Tube Co., Ltd

Website: www.sdxinjiyuan.com

Tel: +86 531 8573 6315

Mobile/WhatsApp/WeChat: +86 188 5315 7756

Email: admin@sdxinjiyuan.com

Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China

Inquiry · Factory-Direct Supply

Request a quotation for Q235B Q345B Hot Dip Galvanized Round Steel Pipe ASTM ERW...

Share your required sizes, steel grades, monthly tonnage and destination port. Our export team returns a loaded-container quotation within 12 hours, including stock status, lead time and full documentation plan.

sales@xinjiyuan-steel.com · +86 531 8888 0000 · Mon-Sat 08:30-19:00 GMT+8

  • 20,000+

    Tons monthly capacity

  • 2,800+

    Specifications in stock

  • 50+

    Countries served

  • 3

    Production lines

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