Description
Factory-direct ASTM A500 Gr.B square and rectangular steel tube supplier — every bundle shipped with original mill test certificates traceable to heat number, verified against ASTM A500 and EN10219 equivalence before container sealing.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Gr.B Square & Rectangular Steel Tube |
| Product Type | Square / Rectangular Steel Tube (Structural Hollow Section) |
| Steel Grade | Q195, Q215, Q235, Q345, #20, #45 (Equivalent: S235JR / S355JR / A500 Grade B / A53 Grade B / STK400 / SS400) |
| Standard | ASTM A500, ASTM A36, ASTM A53, EN10219, EN10210, GB/T 6728, JIS G3466 |
| Section Shape | Square / Rectangular |
| Size Range | Square 20×20mm–500×500mm / Rectangular 20×40mm–300×500mm |
| Wall Thickness | 1.2–20mm |
| Length | 3–12m (random or cut-to-size) |
| Technique | Hot Rolled / ERW |
| Surface Treatment | Hot Rolled / Pre-galvanized (40–80g/m²) / Hot-dip galvanized (200–600g/m²) |
| Tolerance | ±1% |
| Ends | Plain / Beveled (customizable) |
| Processing Service | Bending, Welding, Decoiling, Punching, Cutting |
| Application | Construction & building structures / Solar mounting structures / Machinery frames / Fencing & greenhouse frames / Steel structure engineering |
| MOQ | 1 Ton |
| Origin | China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Building | High-rise building frames, industrial warehouse columns, mezzanine support beams |
| Solar & Renewable Energy | Ground-mounted solar panel racking, inverter support frames, mounting rail systems |
| Machinery Manufacturing | Equipment base frames, conveyor support structures, crane boom sections |
| Infrastructure & Fencing | Highway guardrail posts, greenhouse structural frames, perimeter security fencing |
| Steel Structure Engineering | Portal frame structures, truss chord members, bracing tubes |
Where Grade Equivalence Mapping Prevents Customs Rejection
Mismatched grade declarations between ASTM A500, EN10219, and GB/T 6728 remain the most frequent cause of shipment holds at destination ports.
Procurement teams ordering ASTM A500 Gr.B square and rectangular steel tube for North American projects often receive material certified only to GB/T 6728 or Q345 without documented equivalence. Customs authorities and third-party inspectors at discharge ports increasingly cross-reference declared grades against mill test certificates, and any gap between the purchase order specification and the MTC triggers inspection delays or outright rejection. [NEED_CITE: steel grade equivalence between EN and ASTM standards] The problem compounds when buyers source from suppliers who list multiple standards on quotation sheets but cannot provide traceable chemical composition data linking the shipped material to the specified grade.
Matching Hollow Section Dimensions to Structural Load Paths
When engineers specify ASTM A500 Gr.B square and rectangular steel tube for moment frames or bracing systems, the section geometry directly influences connection detailing and load transfer efficiency. Square sections from 20×20mm up to 500×500mm cover everything from light-gauge purlin supports to heavy column bases, while rectangular profiles such as 200×100mm or 300×200mm provide higher section modulus in the strong axis direction — critical for beam applications where deflection limits govern member selection. Wall thickness options from 1.2mm to 20mm allow the same outer dimensions to serve either non-structural cladding supports or primary load-bearing members, depending on the required moment capacity.
Structural Code Compliance and Surface Protection Strategy
Load-bearing hollow sections must satisfy both material certification requirements and dimensional tolerance standards under applicable engineering codes. ASTM A500 Gr.B square and rectangular steel tube conforming to ±1% tolerance meets the dimensional accuracy requirements for welded connections in AISC-compliant structures, while EN10219 certification becomes mandatory when the same material ships to European markets requiring CE marking. [NEED_CITE: EN 10219 cold-formed hollow section requirements] Surface treatment selection follows the corrosion environment: hot-rolled black finish suits interior applications with controlled humidity, pre-galvanized coating at 40–80g/m² covers temporary outdoor exposure during construction, and hot-dip galvanizing at 200–600g/m² provides long-term protection for coastal or industrial atmospheric conditions.
Decoding Steel Grade Systems for Hollow Section Selection
The Q-series (Q235, Q345), S-series (S235JR, S355JR), and ASTM A500 grade system (Gr.A, Gr.B, Gr.C) represent overlapping but non-identical classification frameworks. Q235 maps to S235JR and A500 Gr.A for general structural use, while Q345 corresponds to S355JR and A500 Gr.B/C where higher yield strength is required for loaded columns or beam-and-column assemblies. ERW (Electric Resistance Welded) manufacturing produces the longitudinal seam through localized heating and forging pressure — suitable for most structural applications where the weld zone is not subjected to cyclic bending. Hot-dip galvanizing at 200–600g/m² adds zinc metallurgically bonded to the steel substrate, providing sacrificial anode protection that outperforms paint systems in humid or salt-exposed environments.
The Hidden Cost of Unverified Mill Test Certificates
Material substitution or forged documentation creates downstream costs that dwarf the initial purchase price differential. When ASTM A500 Gr.B square and rectangular steel tube arrives at a fabrication shop with MTC showing chemistry inconsistent with the ordered grade, the entire batch may require re-testing at buyer’s expense — or worse, get installed before the discrepancy surfaces during structural inspection. [NEED_CITE: consequences of non-conforming steel in structural applications] Negative tolerance abuse — where actual wall thickness falls below the specified minimum — reduces section capacity and triggers rejection during third-party inspection, forcing costly re-procurement with project schedule delays.
Verification and Traceability at Every Shipment Stage
Every ASTM A500 Gr.B square and rectangular steel tube bundle carries original mill test certificates documenting chemical composition and mechanical properties traceable to specific heat numbers. Our in-house laboratory verifies chemistry and tensile properties before release, while SGS or BV third-party inspection remains available for buyers requiring independent validation. The full product range spans over 2,800 specifications across square and rectangular sections, allowing single-source procurement for projects combining multiple size and grade requirements. Custom cutting to exact lengths between 3–12m eliminates on-site waste, while professional container loading plans optimize weight distribution for heavy-wall sections and prevent transit damage to galvanized surfaces.
Documentation & Compliance
- Mill test certificate documenting Q235/Q345 chemical composition and mechanical properties per ASTM A500 Gr.B with heat number traceability
- CE certificate confirming EN10219 compliance for cold-formed structural hollow sections destined for European Union markets
- ISO 9001:2015 quality management certificate covering production processes and inspection procedures
- SGS or BV third-party inspection report available upon request for pre-shipment verification of dimensions and surface quality
- Material traceability documentation linking each bundle to heat number, production date, and test results
- Complete customs documentation package including packing list, bill of lading, and certificate of origin
Packaging, Loading & Delivery
- Hot-rolled black square and rectangular tubes bundled with steel strips at intervals matching 3–12m lengths, with edge protectors preventing corner damage during handling
- Pre-galvanized and hot-dip galvanized sections wrapped in waterproof paper with plastic cap protection on tube ends to preserve zinc coating integrity during ocean transit
- Container loading plans optimized for wall thickness and section size — heavy-wall tubes (10–20mm) loaded on flatbed or open-top containers to avoid overweight penalties, while thin-wall sections (1.2–3mm) maximize 20ft container payload
- Custom cut-to-size lengths processed before shipping, with each bundle labeled showing steel grade, dimensions, heat number, and piece count
-唛头 marking on each bundle displaying ASTM A500 Gr.B designation, size specifications, and heat number for on-site identification
- FOB, CIF, and DDP shipping terms available with professional heavy cargo logistics handling flatbed, open-top, and break-bulk arrangements
Requesting Quotation and Technical Documentation
Submit your ASTM A500 Gr.B square and rectangular steel tube requirements specifying steel grade, section dimensions, wall thickness, length, quantity, and destination port to receive detailed quotation including material cost, processing fees, and shipping terms. We provide original mill test certificates for review before shipment and coordinate SGS/BV third-party inspection scheduling at your request.
Get Your ASTM A500 Gr.B Hollow Section Quote
Send your specifications to receive pricing and mill test certificate samples within 12 hours.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.xjyplate.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@xjyplate.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: What is the grade equivalence between ASTM A500, EN10219, and GB/T 6728 for square and rectangular tubes?
A: Q235 corresponds to S235JR and ASTM A500 Gr.A for general structural applications, while Q345 maps to S355JR and ASTM A500 Gr.B/C where higher yield strength is required. We provide documented equivalence mapping with each shipment to ensure customs clearance and engineering approval.
Q: Can you provide mill test certificates and accept third-party inspection?
A: Yes, every bundle ships with original mill test certificates documenting chemical composition and mechanical properties traceable to heat numbers. SGS or BV third-party inspection is available for pre-shipment verification at buyer’s request.
Q: What is the MOQ for custom cut-to-size square and rectangular tubes?
A: The minimum order quantity is 1 ton, whether you require standard 6m/12m lengths or custom cut-to-size dimensions between 3–12m.
Q: What surface treatment options are available — hot-rolled vs. galvanized?
A: We supply hot-rolled black finish for interior applications, pre-galvanized coating at 40–80g/m² for temporary outdoor protection, and hot-dip galvanized at 200–600g/m² for long-term corrosion resistance in harsh environments.
Q: How do you calculate theoretical weight vs. actual weight and negative tolerance?
A: Theoretical weight is calculated using nominal dimensions and standard steel density (7.85 g/cm³). Our ±1% tolerance ensures actual wall thickness remains within specification, avoiding the negative tolerance abuse that reduces structural capacity.
Secure Your ASTM A500 Gr.B Square and Rectangular Steel Tube Supply
Submit your project specifications to receive quotation and mill test certificate samples within 12 hours.
