Description
Factory-Direct Rectangular Steel Tube Mill — ASTM A500 Gr.B RHS produced in-house with 2,800+ specification coverage and full CE/ISO certification for global project delivery.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Gr.B Rectangular Steel Tube |
| Product Type | Welded Rectangular Steel Tube (RHS) |
| Steel Grade | Gr.B, Q195, Q235, Q345, S235, S275, S355, STK400 |
| Standard | ASTM A500, ASTM A53, GB/T 3091, EN 10219 |
| 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) / Seamless available |
| 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 |
|---|---|
| Construction & Infrastructure | Building frames, column supports, bridge bracing members, platform structures |
| Architectural Facade | Glass curtain wall framing, exposed structural grids, decorative RHS columns |
| Industrial Machinery | Conveyor support structures, equipment bases, crane boom sections |
| Steel Fabrication | Raw material for trusses, portal frames, mezzanine floors, welded assemblies |
What Happens When Tolerance Exceeds ±1% on a Structural Frame Order
Dimensional drift on rectangular steel tubes compounds at every connection point across a multi-story frame.
When wall thickness varies beyond tolerance, bolt-hole alignment fails on site. Fabricators waste days reaming or re-drilling. On curtain wall projects, even 1mm deviation on a long span creates visible misalignment between glass panels. I have seen entire facade batches rejected because the supplier shipped tubes with inconsistent corner radii — standard rounded-corner RHS simply cannot deliver the flush joints that architectural drawings demand. [NEED_CITE: dimensional tolerance requirements for cold-formed structural hollow sections]
Matching Rectangular Profiles to Curtain Wall and Structural Frame Demands
Architectural facades require RHS with true 90-degree corners that sit flush against mullion brackets and glass fixings. Our patented sharp-corner rectangular tube technology produces right-angle profiles that eliminate the rounded transitions found on conventional ERW RHS — critical for projects where exposed steel forms part of the visual design. For structural frames carrying primary loads, the 1–30mm wall thickness range in ASTM A500 Gr.B Rectangular Steel Tube covers everything from light purlin supports to heavy column sections, with ±1% tolerance ensuring predictable section modulus for engineering calculations.
Engineering Compliance and Certification Requirements Across Markets
Structural hollow sections must conform to the governing code at the project site — EN 10219 for European specifiers, ASTM A500 for North American engineers, GB/T 3091 for domestic Chinese construction. Each standard defines its own chemical composition limits, testing frequency, and marking requirements. Shipping ASTM A500 Gr.B Rectangular Steel Tube to the EU without CE marking under EN 10210/EN 10219 triggers customs holds and potential rejection at the port. [NEED_CITE: CE marking requirements for structural steel hollow sections under EN 10219] Surface treatment selection also affects compliance: hot-dip galvanized coatings must meet minimum thickness per ISO 1461 for outdoor exposure, while black painting suits indoor or temporarily protected installations.
Steel Grade Selection and ERW Welding Process Fundamentals
ASTM A500 Gr.B sits in the mid-strength tier of American structural grades, offering reliable weldability and formability for general construction. Its European equivalents — S235, S275, S355 under EN 10219 — provide incrementally higher yield points for designs requiring greater load capacity without increasing section size. The Chinese Q-series (Q195 through Q345) follows a similar progression. ERW welding produces a longitudinal seam that, when properly normalized, delivers mechanical properties consistent with the parent strip — making it cost-effective for non-pressure structural applications. For projects requiring tighter grain structure or heavier walls beyond typical ERW capability, seamless alternatives are available within the same dimensional envelope. Surface treatment choice directly governs service life: galvanized ASTM A500 Gr.B Rectangular Steel Tube resists atmospheric corrosion for decades in coastal or industrial environments, while bare or painted finishes suit controlled indoor conditions or projects where field coating will be applied after fabrication.
Hidden Costs of Sourcing the Wrong Grade or Unverified Material
Ordering S235 when the structural engineer specified S355 means the member will deflect beyond allowable limits under design load — discovered only after erection, when replacement requires dismantling adjacent components. Material without traceable heat numbers fails third-party inspection, delaying handover and triggering liquidated damages. Tubes shipped without proper bracing arrive bent, as I learned the hard way on a West African project where an entire container of RHS was rejected at site. [NEED_CITE: consequences of non-conforming structural steel in construction projects] Certification gaps create customs delays that idle cranes and crews at the port — costs that far exceed the price difference between verified and unverified supply.
Why Project Buyers Source ASTM A500 Gr.B Rectangular Steel Tube Through Our Mill
We operate three dedicated production lines covering 2,800+ specifications — from 15×20mm small sections to 700×800mm heavy structural profiles — eliminating the need to split orders across multiple suppliers. Our in-house physical and chemical laboratory tests every heat for composition, yield, tensile, and elongation before release, with results documented on EN 10204 3.1 mill test certificates. The 41 invention patents include China’s original sharp-corner rectangular tube process, filling a gap that standard mills cannot address for architectural and facade work. Full international certification — ISO 9001:2015, Lloyd’s CE under EN 10210/EN 10219, Singapore FPC, plus SGS and BV verification — clears customs in regulated markets without supplementary testing. We supply designated projects for major state-owned enterprises and listed companies, exporting to 50+ countries with professional container loading that prevents the bending damage I witnessed early in my career.
Documentation & Compliance
- Mill Test Certificate documenting ASTM A500 Gr.B chemical composition, yield strength, and tensile properties per heat number
- CE Certificate confirming compliance with EN 10219 for cold-formed structural hollow sections, issued under Lloyd’s registration
- ISO 9001:2015 Quality Management System certificate covering the full production and testing process
- SGS or BV third-party inspection report verifying dimensional accuracy, surface quality, and marking before shipment
- Material traceability linking each bundle to its heat number, strip coil, and production date
- Export customs documents including packing list, bill of lading, and certificate of origin formatted for destination port requirements
Packaging, Loading & Delivery
- ASTM A500 Gr.B Rectangular Steel Tube bundled with high-tensile steel strips at intervals preventing shift during ocean transit, sized to match 5.8m, 6m, or 12m lengths
- Galvanized RHS wrapped with edge protectors and moisture barrier paper to preserve zinc coating integrity through humid port storage and sea freight
- Container loading plans optimized for 20ft and 40ft GP/HC units, nesting smaller rectangular sections inside larger ones to maximize payload per shipment
- Cut-to-length service available for random or fixed lengths, reducing on-site waste and handling for curtain wall contractors receiving 15×20mm through 200×100mm profiles
- Each bundle marked with heat number, steel grade (Gr.B / S355 / Q345), dimensions, and length in weather-resistant stencil for site identification
- FOB, CIF, and DDP shipping terms available, with professional lashing and dunnage preventing contact damage between black-painted and galvanized surfaces in mixed loads
Starting Your ASTM A500 Gr.B Rectangular Steel Tube Inquiry
Submit your section dimensions, wall thickness, steel grade, surface treatment preference, and destination port — we return a detailed quotation with unit pricing, production lead time, and certification package within 12 hours. For non-standard sizes outside the 15×20mm to 700×800mm range, our engineering team reviews feasibility and provides a custom production proposal. Request mill test certificates and third-party inspection terms upfront to confirm compliance with your project specification before placing the order.
Frequently Asked Questions
Q: Can you supply ASTM A500 Gr.B Rectangular Steel Tube with CE marking for European projects?
A: Yes. Our production carries Lloyd’s CE certification under EN 10210 and EN 10219, covering cold-formed welded structural hollow sections. We provide the Declaration of Performance and factory production control documentation required for EU customs and project handover.
Q: What is the minimum order quantity for custom non-standard rectangular sizes?
A: Our standard MOQ is 5 Tons. For non-standard dimensions outside the 15×20mm to 700×800mm catalogue range, we review tooling requirements and provide a specific MOQ based on section complexity and production setup.
Q: How do you ensure corner quality on rectangular tubes for architectural facades?
A: Our patented sharp-corner rectangular tube process produces true 90-degree internal and external corners, eliminating the rounded transitions typical of conventional ERW RHS. This meets the flush-joint requirements of glass curtain wall framing and exposed architectural steel.
Q: Do you provide third-party inspection before shipment?
A: Yes. We arrange SGS, BV, or other nominated third-party inspection at our facility before loading. The inspection covers dimensional verification, surface quality, marking, and packaging — with a formal report issued for your records and customs clearance.
Q: What surface treatment options are available for outdoor structural applications?
A: We offer hot-dip galvanized coating for long-term corrosion resistance in exposed environments, black painting for indoor or temporarily protected installations, and varnish coating for specific aesthetic or protective requirements. Bare mill finish is also available for projects where field coating will be applied after fabrication.
Get Your ASTM A500 Gr.B Rectangular Steel Tube Quotation
Send your specification — section size, wall thickness, grade, quantity, and destination — to receive pricing, mill test certificate samples, and production lead time within 12 hours.
WhatsApp/WeChat: +86 188 5315 7756 | Email: admin@sdxjypipe.com
