Description
Factory-Direct ASTM A500 GR.B Rectangular Steel Tube Pricing — Every ASTM A500 GR.B rectangular steel tube we ship comes straight from our own ERW mill, eliminating trader markups while keeping full mill test traceability per heat number.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 GR.B Rectangular Steel Tube |
| Product Type | Welded Rectangular Steel Tube / RHS Hollow Section |
| Steel Grade | Gr.B, S235, S275, S355, STK400, Q195, Q235, Q345 |
| 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 | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures / Construction frames / Curtain wall / Building pipe / Support tubes / Machinery |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Industrial plant steel frames, pipe rack supports, equipment platform structures |
| Construction Companies | High-rise building columns, curtain wall mullions, mezzanine floor beams |
| Machinery Manufacturers | Conveyor frame uprights, crane boom sections, agricultural equipment chassis |
| Infrastructure Developers | Bridge handrail posts, sound barrier support columns, solar mounting structures |
Why Missing Mill Test Certificates Cost a Dubai Waterfront Project an Entire Container
An ASTM A500 GR.B rectangular steel tube without traceable chemistry is just a hollow box of risk.
Early in my career, we loaded a batch of thin-wall rectangular and square profiles for a Dubai waterfront development. No one questioned the mill certificates at origin. When the container opened at Jebel Ali, the site engineer ran a portable spectrometer on three random tubes — the manganese content didn’t match GR.B requirements. The entire shipment was rejected. The loss wasn’t just the steel; it was the crane time, the delayed formwork, and the re-procurement freight. [NEED_CITE: EN 10219 cold-formed hollow section chemical composition requirements]
That rejection happened because specification gaps and certification gaps compound. Buyers ordering an ASTM A500 GR.B rectangular steel tube supplier often face fragmented sourcing — pipes from one mill, plates from another, fabrication from a third — with no single party responsible for material consistency. When customs inspectors at EU or GCC ports request CE EN 10219 documentation and the trader can only produce a commercial invoice, the container sits at the terminal accumulating demurrage. [NEED_CITE: steel grade equivalence between ASTM A500 and EN 10219 standards]
How ERW Welded Rectangular Tubes Match Structural Frame Demands
An ASTM A500 GR.B rectangular steel tube in the 100×200mm to 400×600mm range carries bending loads efficiently because the rectangular geometry places more material at the extreme fibers where stress peaks. For curtain wall mullions and mezzanine beams, the flat faces simplify bolted or welded connections to gusset plates — no complex node detailing required. Our ERW process controls the weld seam through real-time ultrasonic inspection, ensuring the longitudinal seam matches the parent metal in tensile behavior. When projects specify S355 or Q345 grades for heavier load paths, the same rectangular tooling delivers those grades without changing connection geometry.
Structural Compliance and Corrosion Protection Selection
Engineering codes such as EN 1993 and AISC 360 require that hollow section dimensions and wall thickness conform to the tolerance band declared in the governing standard — for ASTM A500 GR.B rectangular steel tube orders, that means the ±1% tolerance we hold across the 15×20mm to 700×800mm range. [NEED_CITE: AISC 360 hollow structural section dimension tolerance requirements] For outdoor structures in coastal or industrial atmospheres, hot-dip galvanized coating provides decades of cathodic protection, while black painting suits indoor frames where appearance and initial cost matter more than long-term corrosion resistance. Bare tubes ship for projects that handle surface treatment on-site to match adjacent components. Certification alignment is equally critical: EU-bound shipments need CE marking under EN 10210 or EN 10219, while North American projects demand ASTM A500 compliance with proper heat-level traceability. Custom cut-to-length at 5.8m, 6m, or 12m reduces on-site welding and waste.
Steel Grade Selection and ERW Welding Fundamentals
The ASTM A500 GR.B rectangular steel tube sits in a mid-range yield category within the ASTM system — Gr.B requires higher minimum yield than Gr.A, making it the default for structural frames where deflection limits govern member sizing. When buyers cross-reference to European or Chinese standards, S235 roughly parallels Q235, while S355 aligns with Q345B in yield class, though exact chemical boundaries differ by standard. [NEED_CITE: steel grade cross-reference ASTM A500 EN 10219 GB/T 3091] ERW welding forms the tube by rolling a flat strip into a rectangular profile and passing high-frequency current through the open edges to forge a longitudinal seam — this process suits wall thicknesses from 1mm to 30mm and keeps production costs lower than seamless alternatives for non-pressure applications. Surface treatment choice directly affects service life: galvanized coatings of 60–80 microns resist atmospheric corrosion for decades, while varnish or black paint provides short-term protection during construction phases. Our proprietary sharp-corner rectangular tube technology produces tighter corner radii than conventional roll-forming, improving load transfer at welded connections and giving architectural facades a cleaner visual line.
Hidden Costs of Procuring the Wrong Grade or Unverified Thickness
Specifying Gr.B when the supplier delivers unmarked material that tests as Gr.A means lower yield strength — the structural engineer’s deflection calculations become invalid, and the building inspector will fail the frame during final inspection. Missing CE documentation on an ASTM A500 GR.B rectangular steel tube shipment to Rotterdam means customs holds the container, and the importer pays storage fees while scrambling for retroactive test reports. Wall thickness below the declared tolerance — say 2.7mm instead of 3.0mm on a 150×100×3mm tube — reduces the section modulus, meaning the member carries less load than the structural drawings assume. [NEED_CITE: consequences of negative wall thickness tolerance on structural hollow section load capacity] These failures don’t show up in purchase price comparisons; they surface during erection, inspection, or — worst case — under service load.
Why Engineering Procurement Teams Source ASTM A500 GR.B Rectangular Steel Tube Here
Every ASTM A500 GR.B rectangular steel tube we produce runs through our in-house physical and chemical laboratory — incoming strip is verified for chemistry before forming, weld seams undergo ultrasonic testing during production, and finished tubes are sampled for tensile and flattening tests before release. We hold 41 invention patents, including proprietary sharp-corner rectangular tube tooling that produces corner radii tight enough for architectural curtain wall systems where conventional ERW tubes leave visible gaps at welded nodes. Our mill covers 2,800+ specification combinations across square tubes, rectangular tubes, round pipes, plates, and section steel — so when an EPC contractor needs rectangular tubes, H-beams, and fabricated base plates for the same industrial project, one purchase order and one quality file cover everything. CE certification under EN 10210 and EN 10219, ISO 9001:2015 registration, and SGS/BV third-party inspection availability mean the documentation package clears customs in EU, GCC, and Southeast Asian ports without delays. We ship to 50+ countries with professional container loading plans — every waterfront or heavy-gauge order gets a custom stacking diagram before the container seal is applied.
Documentation & Compliance
- Mill Test Certificate documenting Gr.B, S235, S275, or S355 chemical composition and mechanical properties per ASTM A500 or EN 10219, traceable to heat number
- CE Certificate of Compliance under EN 10210 (hot-finished) or EN 10219 (cold-formed) for rectangular hollow sections exported to EU member states
- ISO 9001:2015 quality management system certificate covering the full ERW welding and finishing process for ASTM A500 GR.B rectangular steel tube production
- SGS or BV third-party inspection report verifying dimensional tolerance, surface coating thickness, and weld seam quality before container sealing
- Material traceability sheet linking each bundle to its heat number, strip coil origin, and production date for project handover records
- Customs documentation package including commercial invoice, packing list, bill of lading, and certificate of origin formatted for destination port requirements
Packaging, Loading & Delivery
- ERW welded rectangular tubes bundled with high-tensile steel strips at intervals matched to the 5.8m, 6m, or 12m length, preventing bundle spread during crane lifts
- Galvanized ASTM A500 GR.B rectangular steel tube bundles wrapped with rubber edge protectors to preserve the zinc coating against chafing during ocean transit
- Container loading optimized by stacking sequence — heavier 30mm wall thickness tubes on the bottom tier, thin-wall 1–2mm sections on top with timber bracing to prevent shifting
- Cut-to-length service available for 5.8m, 6m, 11.8m, or 12m定尺 requirements, reducing on-site cutting waste for curtain wall and mezzanine frame projects
- Each bundle tagged with heat number, steel grade (Gr.B / S355 / Q345), size marking, and production date for site-level material traceability
- Shipping terms FOB, CIF, or DDP to ports across EU, North America, Middle East, Southeast Asia, and South America with real-time container tracking
Getting Your ASTM A500 GR.B Rectangular Steel Tube Quote Moving
Submit your specification sheet — section dimensions, wall thickness, steel grade, total tonnage, and destination port — and we return a detailed quotation within 12 hours, including unit pricing, production lead time, applicable certifications, and payment terms. For non-standard dimensions outside the 15×20mm to 700×800mm range, our engineering team provides a custom feasibility assessment and tooling timeline. Request original mill test certificates and third-party inspection scope before contract signing to confirm compliance with your project specification.
Frequently Asked Questions
Q: How does ASTM A500 GR.B compare to EN S355JR and GB Q345B for rectangular hollow sections?
A: All three grades fall in a similar mid-to-high yield range within their respective standards, making them suitable for structural frames and load-bearing applications. However, the exact chemical composition limits and mechanical property test methods differ — ASTM A500 uses imperial-influenced test protocols while EN 10219 follows European impact testing requirements. We supply all three grade systems and provide cross-reference documentation so your structural engineer can verify equivalence for the specific project code.
Q: Can you provide mill test certificates and arrange third-party inspection before shipment?
A: Yes. Every batch of ASTM A500 GR.B rectangular steel tube ships with an original mill test certificate documenting chemical composition and mechanical properties, traceable to the heat number. We also coordinate SGS or BV third-party inspection at our facility before container loading, covering dimensional checks, weld seam quality, surface coating thickness, and witness testing.
Q: What is the minimum order quantity for custom non-standard rectangular tube dimensions?
A: Our standard MOQ is 5 Tons. For non-standard dimensions outside the 15×20mm to 700×800mm catalog range, we evaluate tooling feasibility based on the specific size and wall thickness requested. Our 2,800+ specification range covers most structural and architectural requirements without custom tooling.
Q: Which surface treatment is best for outdoor rectangular steel tube structures in coastal environments?
A: Hot-dip galvanized coating provides the longest corrosion protection life for coastal and industrial atmospheres, typically delivering decades of maintenance-free service. Black painting suits indoor structures or projects where the client handles final coating on-site. Bare tubes ship for fabrication shops that apply their own coating system to match adjacent components.
Q: How do you optimize container loading for mixed-size rectangular tube orders?
A: Every container load receives a custom stacking diagram before sealing. Heavy-wall tubes are positioned on the bottom tier, thin-wall sections on top with timber bracing to prevent transit shifting. For orders combining multiple sizes — say 100×50×3mm and 200×100×6mm — we nest smaller sections inside larger ones where geometry allows, maximizing container payload and reducing freight cost per ton.
[Request Your ASTM A500 GR.B Rectangular Steel Tube Quotation Today]
Send your specifications — dimensions, wall thickness, grade, quantity, and destination — to receive a detailed quotation with mill test certificate scope within 12 hours.
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
