Description
Factory-Direct ASTM A500 GR.B Supply — Hot dipped galvanized rectangular steel tubes produced on our own ERW lines with zinc coating tested before every shipment, shipped to 50+ countries without trading company markups.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 GR.B Galvanized Rectangular Steel Tube |
| Product Type | Galvanized Rectangular Steel Tube (RHS) |
| Steel Grade | GR.B, S235, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091 |
| Section Shape | Rectangular |
| Size Range | 15mm×20mm – 700mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | ERW / Welded |
| Surface Treatment | Hot Dipped Galvanized (Zinc Coated 200–700 g/m²) / Black Painting |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures / Building construction / Curtain wall / Support tubes / Structural frames |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Industrial plant support frames, pipe rack structures, equipment skid bases |
| Construction Companies | High-rise building columns, curtain wall mullions, mezzanine floor beams |
| Machinery Manufacturers | Conveyor system frames, automation equipment bases, corrosion-resistant structural supports |
| Infrastructure Developers | Bridge handrail posts, solar mounting structures, signage gantries |
What Zinc Coating Weight Actually Means for Your Project Timeline
Choosing 200 g/m² for a coastal project guarantees a return visit for repainting.
I have seen galvanized rectangular tubes arrive at a Middle East job site with visible white rust within weeks because the buyer specified indoor-grade coating for an outdoor marine environment. The ASTM A500 GR.B galvanized rectangular steel tube supplier you choose must understand that zinc coating weight is not a line item to negotiate down — it is the difference between a structure that lasts twenty years and one that fails inspection before handover. Inconsistent coating thickness, missing mill test certificates, and fragmented sourcing across multiple vendors create compounding delays that no amount of expediting can recover [NEED_CITE: hot dip galvanizing coating thickness standards for structural steel].
Matching Rectangular Profiles to Structural Load Paths
The 1–30 mm wall thickness range in our ASTM A500 GR.B galvanized rectangular steel tube lineup covers everything from light-gauge curtain wall mullions to heavy-duty industrial support columns. The rectangular cross-section provides higher moment of inertia along the strong axis compared to round pipe, making it the practical choice for beam applications where bending resistance matters more than torsional load. Our ERW welding process produces a consistent weld seam that passes ultrasonic inspection across the full 700mm×800mm size range, and the ±1% tolerance holds tight enough for pre-fabricated structural frames where field reaming is not an option.
Engineering Compliance Across Destination Markets
Structural designers specifying EN 1993 or AISC standards need traceable material certification that matches the steel grade on the drawing. An ASTM A500 GR.B galvanized rectangular steel tube shipped to the EU requires CE marking under EN 10210 or EN 10219 — without it, customs holds the container and the project crane sits idle. Our in-house physical and chemical laboratory tests every heat before galvanizing, and we provide third-party inspection through SGS or BV for buyers who need independent verification [NEED_CITE: EN 10219 cold-formed hollow section compliance requirements]. The 5.8m and 11.8m standard lengths align with container dimensions to minimize on-site cutting, while random length orders serve projects with non-standard bay spacing.
Steel Grade Selection and Galvanizing Process Fundamentals
GR.B under ASTM A500 specifies a minimum yield strength tier suitable for general structural framing, while S355 serves heavier load-bearing applications where higher strength-to-weight ratio reduces section size and material cost. The hot dip galvanizing process immerses the welded rectangular tube in molten zinc at approximately 450°C, creating a metallurgical bond that produces zinc-iron alloy layers harder than the base steel — this is why galvanized RHS resists abrasion during transport and installation better than painted alternatives. Coating weight selection follows environment severity: 200 g/m² suits indoor or dry climates, 400 g/m² covers typical outdoor exposure, and 700 g/m² addresses industrial or marine corrosion zones. The ERW welding technique used for these tubes offers cost efficiency over seamless alternatives at the structural dimensions involved, with the weld zone fully covered by the galvanizing bath to prevent localized corrosion initiation.
Hidden Costs of Specifying the Wrong Coating Class
Ordering galvanized RHS based on price per ton alone ignores the cost structure that matters at project completion. Coating thickness below specification triggers rejection by the site inspector — the entire batch comes back to the galvanizing plant or gets scrapped, adding weeks to the critical path. Missing or incorrect mill test certificates cause customs delays in markets with strict import documentation requirements, and material traceability gaps force expensive re-testing when auditors request heat number verification [NEED_CITE: structural steel certification requirements for international construction projects]. An ASTM A500 GR.B galvanized rectangular steel tube supplier who cannot provide consistent coating weight documentation transfers all of these risks to the buyer’s project budget.
Procurement Confidence Built on Verifiable Process Controls
Every ASTM A500 GR.B galvanized rectangular steel tube leaving our facility passes through an in-house physical and chemical laboratory that verifies base metal composition before galvanizing and measures coating thickness after the process completes. We operate three dedicated production lines covering over 2,800 specifications, so your non-standard rectangular dimensions do not require sourcing from a second vendor who uses different material certificates. Our 41 patented technologies include proprietary sharp-corner rectangular tube manufacturing that eliminates the radius gaps typical in standard ERW dies — this matters for curtain wall connections where flush fit reduces field adjustment time. CE certification under EN 10210/10219, ISO 9001:2015 registration, and Singapore FPC approval cover the documentation requirements for EU, North American, and Southeast Asian projects. Professional loading plans optimize container utilization for the 6m and 12m lengths, and our logistics team coordinates FOB, CIF, and DDP shipments to 50+ countries with real-time tracking.
Documentation & Compliance
- Mill test certificate documenting GR.B chemical composition and mechanical properties per ASTM A500, with heat number traceability to the original coil
- CE certificate under EN 10210/10219 for rectangular hollow sections shipped to European Union member states
- ISO 9001:2015 quality management certificate covering the full production and galvanizing process
- SGS or BV third-party inspection report verifying zinc coating thickness and dimensional tolerance before container sealing
- Material traceability sheet linking each bundle to its heat number, coating weight test result, and production date
- Customs documentation package including packing list, bill of lading, and certificate of origin formatted for the destination port
Packaging, Loading & Delivery
- Galvanized rectangular tubes bundled with steel strips and edge protectors to prevent zinc coating damage from friction during ocean transit
- Surface protection maintained through proper stacking separation — galvanized RHS requires non-metallic dunnage to avoid contact corrosion between layers
- Container loading plans optimized for 6m and 12m lengths to maximize payload within the 1–30 mm wall thickness weight range, reducing per-ton freight cost
- Random length and cut-to-size orders available within the 5.8m to 12m range, with plain ends deburred for safe handling
- Heat number and steel grade stenciled on each tube bundle for site identification and inspection traceability
- FOB Jinan, CIF destination port, and DDP door-to-door logistics options with tracking updates at each transit milestone
Starting Your Procurement With Complete Specifications
Submit your ASTM A500 GR.B galvanized rectangular steel tube requirements — including outer dimensions, wall thickness, coating weight class, total tonnage, and destination port — and receive a detailed quotation with production timeline and applicable certification documents within 12 hours. Non-standard sizes outside the 15mm×20mm to 700mm×800mm range are available for review with your drawing or specification sheet.
Request Your Galvanized RHS Quotation and Mill Test Certificate
Send your specifications via email to admin@sdxjysteel.com or contact us on WhatsApp at +86 188 5315 7756 to begin your procurement process.
Frequently Asked Questions
Q: What is the difference between ASTM A500 GR.B and EN 10210 S355 for rectangular steel tubes?
A: ASTM A500 GR.B and EN 10210 S355 belong to different standard systems — ASTM is used primarily in North America while EN standards apply in the European Union. Both specify minimum yield strength requirements for structural hollow sections, but the exact values differ between the two frameworks. We produce rectangular tubes to either standard based on your project specification, and can provide cross-reference documentation for engineers working across both systems [NEED_CITE: steel grade equivalence between ASTM and EN standards].
Q: How do I select the right zinc coating weight for my project environment?
A: Coating weight selection depends on the corrosion severity of the installation environment. Our hot dip galvanized rectangular steel tubes are available in 200 g/m² for indoor or sheltered applications, 400 g/m² for standard outdoor exposure, and 700 g/m² for industrial atmospheres or coastal marine environments. If your project specification references a particular coating class or service life requirement, we can recommend the appropriate zinc weight based on established corrosion data.
Q: Can you produce non-standard rectangular dimensions outside your listed size range?
A: Yes. Our production lines cover over 2,800 specifications, and we manufacture custom non-standard rectangular sizes beyond the 15mm×20mm to 700mm×800mm catalog range. Submit your required dimensions with wall thickness and quantity, and we will confirm feasibility, tooling requirements, and minimum order quantity for the custom profile.
Q: What certification documents do I need for customs clearance in the EU?
A: Rectangular steel tubes shipped to the European Union require CE marking under EN 10210 (hot finished) or EN 10219 (cold formed), along with a mill test certificate documenting chemical composition and mechanical properties. We hold CE certification for both standards and include the complete documentation package — CE declaration, mill test certificate, packing list, bill of lading, and certificate of origin — with every EU-bound shipment.
Q: What is your minimum order quantity for galvanized rectangular steel tubes?
A: The minimum order quantity is 1 Ton for standard sizes within our catalog range. For custom non-standard dimensions or special coating weight requirements, the MOQ may vary depending on production setup. Contact us with your specifications to confirm the applicable minimum for your order.
