Description
Factory-Direct ASTM A500 Gr.B Supply — Seamless and welded square and rectangular hollow sections produced on three dedicated lines in Jinan, shipped with full mill documentation to 50+ countries.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Gr.B Seamless Square and Rectangular Hollow Section |
| Product Type | Square and Rectangular Steel Tube (Seamless / Structural Hollow Section) |
| Steel Grade | Q195, Q215, Q235, Q355, S235JR, S355JR, A500 Grade A, A500 Grade B, A500 Grade C, A53 Grade A, A53 Grade B, A36, STK400, SS400, ST42.2, S195, S355J2H, S355J0H, #20, #45 |
| Standard | ASTM A500, ASTM A53, ASTM A36, EN 10219, EN 10210, GB/T 6728, JIS G3466 |
| Section Shape | Square / Rectangular |
| Size Range | Square: 20×20 mm – 500×500 mm; Rectangular: 20×40 mm – 300×500 mm |
| Wall Thickness | 1.2 mm – 20 mm |
| Length | 3 m – 12 m (random / fixed) |
| Technique | Hot Rolled / Seamless / ERW |
| Surface Treatment | Pre-galvanized (40–80 g/m²), Hot-dip galvanized (200–600 g/m²), Hot Rolled, Black, Oiled, or per customer requirement |
| Tolerance | ±1% |
| Ends | Plain / Beveled (per customer requirement) |
| Application | Structural frames, solar structures, machinery, shipbuilding, bridges, pressure vessels |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Industrial plant structural frames, pipe rack supports, equipment platforms |
| Construction Companies | High-rise building columns, bridge handrails, solar farm mounting structures |
| Machinery Manufacturers | Conveyor system frames, crane booms, hydraulic cylinder housings |
| Infrastructure & Civil Works | Highway guardrail posts, airport terminal roof trusses, fencing systems |
| Energy & Pressure Equipment | Oil storage tank shells, pressure vessel supports, power engineering structures |
Where Wall-Thickness Tolerance Decides Structural Acceptance on an ASTM A500 Gr.B Order
A ±1% tolerance on a 20 mm wall saves tons of re-cutting and keeps load calculations valid.
I once watched a Southeast Asian client reject an entire container of square tubes because the wall thickness ran past the negative tolerance limit. The third-party inspector pulled random pieces, measured with an ultrasonic gauge, and the whole lot was flagged. That single batch failure cost weeks of delay and a full re-rolling cycle. On any ASTM A500 Gr.B seamless square and rectangular hollow section, wall consistency is not a paperwork detail — it is the difference between passing site inspection and shipping steel back to the port. Buyers who source from multiple suppliers without in-house lab verification often discover the gap only when the container arrives. [NEED_CITE: ultrasonic wall-thickness testing methods for structural hollow sections]
Matching Cross-Sections to Load Paths in Structural Frames
An ASTM A500 Gr.B seamless square and rectangular hollow section carries bending and compression more efficiently than open profiles because the closed section resists torsion. For EPC contractors building industrial frames, the square and rectangular shapes allow flush bolted connections at nodes, reducing gusset plate complexity. When the same tube is specified for solar mounting structures, the pre-galvanized or hot-dip galvanized surface handles coastal and high-humidity environments without additional field coating. Our proprietary sharp-corner rectangular tube technology — one of 41 patented processes — keeps corner radii tight enough for aesthetic architectural facades while still meeting structural load requirements.
Compliance Paths for EU, North American, and Asian Projects
Engineering specifications written to EN 1993 or AISC demand traceable material certification before the tube is welded into a load-bearing member. For EU-bound shipments, the ASTM A500 Gr.B seamless square and rectangular hollow section must carry CE marking under EN 10210 (hot-formed) or EN 10219 (cold-formed), otherwise customs holds the cargo at the port of entry. North American projects typically require ASTM A500 Gr.B with mill test certificates conforming to EN 10204 3.1. Asian infrastructure tenders often accept JIS G3466 or GB/T 6728 equivalents. Choosing the correct standard at the inquiry stage avoids re-certification costs later. [NEED_CITE: CE marking requirements for structural hollow sections under EN 10210 and EN 10219]
Reading the Steel Grade Map Across ASTM, EN, and GB Systems
Specifying A500 Grade B on a drawing does not mean you cannot source from a Chinese mill — the grade equivalence is well established. Q355 in the GB system, S355JR in the EN system, and A500 Grade C in the ASTM system all target similar yield strength ranges, though exact chemical composition and impact testing requirements differ. For non-critical structural members, Q235 or S235JR offers cost savings while still meeting general frame requirements. When low-temperature impact toughness matters — such as offshore platforms or cold-region bridges — S355J2H or S355J0H grades specify Charpy testing at sub-zero temperatures. The seamless and ERW processes both produce these grades; the choice between them depends on wall thickness, diameter-to-thickness ratio, and the pressure rating required by the design code.
Hot-dip galvanizing at 200–600 g/m² suits buried or marine applications where corrosion allowance must last decades, while pre-galvanized at 40–80 g/m² is sufficient for indoor machinery frames or temporary structures. Black or oiled finishes are specified when the tube will be painted on site or welded without zinc fume concerns. Wall thickness from 1.2 mm to 20 mm covers everything from light gauge purlins to heavy column sections, and the ±1% tolerance ensures the theoretical weight used in structural calculations matches the delivered product.
The Hidden Cost of Accepting Tubes Without Verified Certification
Buying ASTM A500 Gr.B seamless square and rectangular hollow section at the lowest invoice price often shifts cost downstream. Material without a traceable heat number cannot be verified against the mill test certificate, meaning the engineer cannot sign off on the structural submission. Missing CE or EN 10204 3.1 documentation triggers customs holds in the EU, generating demurrage charges that exceed the original price saving. Negative tolerance abuse — where the actual wall is consistently below the nominal — reduces the section modulus and forces the contractor to either reinforce on site or replace members entirely. [NEED_CITE: consequences of non-conforming steel certificates in international construction projects]
Why Engineers Specify Our Mill for ASTM A500 Gr.B Hollow Sections
We roll the ASTM A500 Gr.B seamless square and rectangular hollow section on three dedicated production lines in Jinan, covering over 2,800 specifications without outsourcing to trading companies. Every heat is tested in our in-house physical and chemical laboratory before the tube leaves the line, so the mill test certificate you receive reflects actual production data, not a template. Our sharp-corner rectangular tube patent fills a gap that standard cold-forming cannot achieve — tight internal radii for architectural and mechanical applications where appearance and fit-up matter. We hold CE certification under both EN 10210 and EN 10219, ISO 9001:2015 registration, and accept SGS or BV third-party inspection at any stage. Non-standard dimensions outside the catalog range are available with a 1-ton minimum order, and our loading team optimizes container stowage for the 3 m to 12 m length range to reduce freight cost per ton.
Documentation & Compliance
- Mill test certificate documenting A500 Grade B chemical composition and mechanical properties per ASTM A500, traceable by heat number
- CE certificate under EN 10210 for hot-formed or EN 10219 for cold-formed square and rectangular hollow sections, required for EU customs clearance
- ISO 9001:2015 quality management certificate covering the full production and inspection process at the Jinan facility
- SGS or BV third-party inspection report available upon request, verifying wall thickness, dimensions, and surface coating weight
- Material traceability report linking each bundle to its heat number, steel grade (Q355, S355JR, A500 Gr.B, etc.), and production date
- Export documentation package including packing list, bill of lading, and certificate of origin for the destination country
Packaging, Loading & Delivery
- Seamless and ERW square tubes bundled with steel strips and edge protectors, preserving pre-galvanized or hot-dip galvanized coating during ocean transit
- Hot-dip galvanized ASTM A500 Gr.B tubes wrapped with waterproof cloth and separated by rubber spacers to prevent zinc layer scratching
- Container loading plans optimized for 6 m and 12 m fixed lengths, maximizing payload for 20-foot and 40-foot open-top or standard dry containers
- Custom cutting to project-specific lengths within the 3 m – 12 m range, with beveled or plain ends as specified on the purchase order
- Each bundle labeled with heat number, steel grade, size, and length for site identification and traceability during installation
- Shipping terms available as FOB, CIF, or DDP to ports and project sites across 50+ countries, with real-time tracking from Jinan to destination
Starting Your ASTM A500 Gr.B Procurement
Submit your specification sheet — including section size, wall thickness, steel grade, quantity, and destination port — and receive a detailed quotation with production lead time, applicable certifications, and payment terms within 12 hours. For non-standard dimensions or sharp-corner rectangular tubes, our technical team will confirm feasibility and provide a custom production plan before you commit to a deposit.
Request Your Quotation and Mill Test Certificate
Send your ASTM A500 Gr.B seamless square and rectangular hollow section requirements to admin@sdxjysteel.com or contact us via WhatsApp at +86 188 5315 7756. Our team will return a detailed offer including unit price, certification package, and estimated delivery schedule.
Frequently Asked Questions
Q: How does Q355 map to ASTM A500 Gr.B for cross-standard procurement?
A: Q355 in the Chinese GB system and S355JR in the EN system are commonly accepted as equivalents to ASTM A500 Grade C for general structural applications. For projects strictly requiring A500 Gr.B, we produce to that exact standard and provide the corresponding mill test certificate.
Q: Can you provide EN 10204 3.1 Mill Test Certificates and third-party SGS or BV inspection?
A: Yes. Every shipment of ASTM A500 Gr.B seamless square and rectangular hollow section includes an EN 10204 3.1 mill test certificate with chemical composition and mechanical properties. SGS or BV third-party inspection is available at the mill before shipment.
Q: What is the MOQ for custom non-standard dimensions outside the catalog range?
A: The minimum order quantity is 1 Ton. For non-standard sizes beyond the 20×20 mm to 500×500 mm square or 20×40 mm to 300×500 mm rectangular range, we confirm production feasibility and lead time before accepting the order.
Q: Should I specify pre-galvanized or hot-dip galvanized for my project environment?
A: Pre-galvanized coating at 40–80 g/m² suits indoor or dry environments and offers cost efficiency. Hot-dip galvanized at 200–600 g/m² is recommended for outdoor, marine, or high-humidity applications where long-term corrosion resistance is required.
Q: Do you handle full export documentation and door-to-door logistics?
A: Yes. We provide FOB, CIF, and DDP shipping terms with a complete documentation package including mill test certificates, packing list, bill of lading, CE certificate, and certificate of origin. Professional container loading optimization reduces freight cost for the 3 m to 12 m length range.
Get Your ASTM A500 Gr.B Hollow Section Quote Today
Email your specifications to admin@sdxjysteel.com or message +86 188 5315 7756 on WhatsApp to receive a detailed quotation with mill test certificate and delivery timeline within 12 hours.
