Description
Factory-direct pricing with no middlemen — every ASTM A500 square and rectangular steel tube rolls off our own ERW lines in Jinan, shipped with original mill test certificates traceable to heat number.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 Square and Rectangular Steel Tube |
| Product Type | Square and Rectangular Steel Tube (Hollow Structural Section) |
| Steel Grade | Gr.B, S235, S275, S355, STK400, Q195–Q690 |
| Standard | ASTM A500, ASTM A53, GB/T3091, EN 10219, EN 10210 |
| Section Shape | Square / Rectangular |
| Size Range | 19mm×19mm – 800mm×800mm |
| Wall Thickness | 1 – 30 mm |
| Length | 5.8m / 6m / 11.8m / 12m / Random Length |
| Technique | ERW / Welded or Seamless |
| Surface Treatment | Black Painting / Galvanized / Varnish / Bare |
| Tolerance | ±1% |
| Ends | Plain |
| Application | Steel structures / Construction frames / Building structures / Curtain wall systems / Support tubes / Machinery / Scaffolding |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| EPC Contractors | Industrial plant steel frameworks, pipe rack supports, equipment base structures |
| Construction Companies | High-rise building columns, bridge support frames, curtain wall mullions |
| Machinery Manufacturers | Conveyor system frames, crane boom sections, hydraulic equipment bases |
| Infrastructure Developers | Scaffolding uprights, sound barrier posts, solar mounting structures |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A 0.5mm negative tolerance deviation on a 6mm wall spec turns a 200×200 ASTM A500 square tube into a liability, not an asset.
On a Riyadh high-rise project years back, a batch of 200×200 square tubes shipped riding the extreme negative tolerance — 5.2mm actual on a 6mm nominal. The client’s SGS re-inspection flagged it at Jebel Ali transit. Two containers held, three weeks of delay, air-freight replacement ate the entire margin. That’s when the lesson burned in: “within standard” isn’t good enough for structural frames where every column carries calculated loads. [NEED_CITE: EN 10219 cold-formed hollow section dimensional tolerance requirements]
Global buyers sourcing an ASTM A500 square and rectangular steel tube supplier face three compounding risks: inconsistent wall thickness that fails structural verification, missing or forged mill test certificates that trigger customs holds, and fragmented sourcing across pipe, plate, and section suppliers that multiplies coordination costs. When the tolerance on a 30mm wall tube drifts beyond ±1%, the theoretical weight calculation no longer matches the actual load-bearing capacity — and the engineer’s stamp means nothing if the steel doesn’t hold.
Matching Hollow Section Profiles to Structural Load Paths
An ASTM A500 square and rectangular steel tube in Gr.B or S355 grade serves load-bearing frames where bending resistance and torsional rigidity matter more than circular pipes can deliver. The flat surfaces allow direct bolted or welded connections to gusset plates and beam flanges without additional connection brackets — critical for conveyor structures and industrial mezzanines where fabrication speed determines project timelines. For curtain wall mullions and scaffolding uprights, the consistent external dimensions across 2,800+ specifications mean alignment tolerances stay within architectural requirements without on-site grinding or shimming.
Engineering Compliance and Certification Requirements
Structural hollow sections destined for EU markets must carry CE marking under EN 10210 or EN 10219, with declaration of performance documentation traceable to the production mill. [NEED_CITE: CE marking requirements for structural steel hollow sections under EN 10219] North American projects specify ASTM A500 Gr.B or Gr.C with mill test certificates showing chemical composition and mechanical properties per heat number. For projects in Singapore and Southeast Asia, FPC certification from approved manufacturers becomes a customs and site-acceptance prerequisite. Wall thickness selection directly influences fire resistance ratings and seismic load calculations — engineers specifying S355 over S235 gain higher yield strength for reduced section sizes, but must verify weldability and notch toughness for cold-climate installations.
Steel Grade Selection and ERW Welding Process
The ASTM A500 specification covers three grades — Gr.A, Gr.B, and Gr.C — with increasing yield and tensile strength requirements. Gr.B remains the most specified grade for general structural applications, balancing formability with adequate strength for building frames and machinery bases. When projects cross borders, grade equivalence becomes critical: EN 10219 S355JR roughly corresponds to ASTM A500 Gr.C in yield strength, while Q345B from the Chinese GB system sits between Gr.B and Gr.C. [NEED_CITE: steel grade equivalence between ASTM A500 and EN 10219 standards]
ERW welding produces a longitudinal seam through high-frequency electric current, creating a weld zone that must meet the same mechanical properties as the parent metal. For square and rectangular tubes formed from coil, the ERW process allows tighter dimensional control on corner radii and flat-face tolerances compared to seamless alternatives — essential when tubes must stack flush in modular construction or fit into laser-cut connection plates. Our proprietary sharp-corner rectangular tube technology achieves corner radii approaching zero, filling a gap in global supply where architectural facades demand crisp internal angles without additional machining.
Surface treatment selection depends on the exposure environment. Black painted or bare finish suits indoor structural applications where fireproofing or intumescent coating will be applied on-site. Hot-dip galvanizing provides corrosion protection for outdoor scaffolding, sound barriers, and coastal installations, though the zinc coating adds thickness that must be accounted for in connection detailing.
Hidden Costs of Tolerance Drift and Certification Gaps
Ordering ASTM A500 square tubes at the lowest unit price without verifying actual wall thickness creates a cascade of downstream costs. When a 6mm nominal wall measures 5.2mm across the full production run, the structural engineer’s load calculations become invalid — the column may pass visual inspection but fail ultrasonic thickness testing at site acceptance. [NEED_CITE: structural steel verification testing requirements for hollow sections]
Missing or incomplete mill test certificates trigger customs holds at destination ports, particularly in EU countries requiring CE documentation under the Construction Products Regulation. Air-freighting replacement material to meet project deadlines erodes the savings from choosing a cheaper supplier. Third-party inspection by SGS or BV before shipment catches tolerance drift and grade substitution before containers seal — a fraction of the cost of project delay.
Why Procurement Teams Source ASTM A500 Tubes From Jinan
Every ASTM A500 square and rectangular steel tube leaving our yard passes through an in-house physical and chemical laboratory that tests incoming coil, monitors weld integrity during ERW formation, and verifies final dimensions against the ±1% tolerance spec. Original mill test certificates document chemical composition and mechanical properties for every heat number, providing full traceability from slab to shipment.
Our three dedicated production lines cover 2,800+ specifications from 19×19mm to 800×800mm with wall thickness reaching 30mm standard and 40mm on custom orders — eliminating the need to source small sections from one supplier and heavy-wall tubes from another. The 41 invention patents include our proprietary sharp-corner rectangular tube process, which produces near-zero internal corner radii for architectural and precision machinery applications where standard ERW forming leaves unacceptable radii.
CE certification under EN 10210 and EN 10219, ISO 9001:2015 quality management, Singapore FPC approval, and third-party verification from SGS, BV, and Lloyd’s Register ensure documentation clears customs in EU, North American, and Southeast Asian ports without delay. Professional loading plans optimize container weight distribution for 6m and 12m lengths, reducing shipping cost per ton compared to random-length suppliers.
Documentation & Compliance
- Mill test certificate documenting Gr.B chemical composition and yield strength per ASTM A500, traceable to heat number
- CE certificate of conformity under EN 10219 for cold-formed structural hollow sections exported to EU markets
- ISO 9001:2015 quality management certificate covering ERW welding, forming, and dimensional inspection processes
- SGS or BV third-party inspection report verifying wall thickness, surface quality, and dimensional tolerance before container loading
- Material traceability sheet linking each bundle to coil heat number, production date, and test results
- Customs documentation package including packing list, bill of lading, and certificate of origin for destination port clearance
Packaging, Loading & Delivery
- ERW welded square and rectangular tubes bundled with high-tensile steel strips, separated by timber dunnage to prevent surface damage during ocean transit
- Galvanized ASTM A500 tubes packaged with edge protectors and waterproof wrapping to preserve zinc coating integrity through humidity exposure
- Container loading plans optimized for 6m and 12m lengths, maximizing payload within 20GP and 40HC weight limits for Gr.B structural sections
- Random length and cut-to-order tubes available in 5.8m, 6m, 11.8m, and 12m, with plain ends deburred and bevel-ready if specified
- Each bundle marked with heat number, steel grade, size, and length in weather-resistant paint stencil for site identification
- FOB, CIF, and DDP shipping terms available to 50+ countries, with door-to-door logistics coordination for EPC project sites
Submit Specifications for Quotation and Mill Test Review
Engineering procurement teams specifying ASTM A500 square and rectangular steel tubes should send section dimensions, wall thickness, steel grade, total tonnage, and destination port to receive a detailed quotation with production lead time and payment terms. We provide original mill test certificates and accept SGS or BV third-party inspection before shipment. For non-standard sizes outside our 2,800+ specification range, custom tooling quotes and minimum order quantities are available upon request.
Frequently Asked Questions
Q: How do ASTM A500 Gr.B, EN 10219 S355, and GB Q345B compare for structural applications?
A: These grades belong to different national standards but serve similar structural roles. ASTM A500 Gr.B is the baseline for North American projects, EN 10219 S355 offers higher yield strength for European designs, and Q345B sits between Gr.B and Gr.C in the Chinese system. We supply all three from the same production lines with full cross-reference documentation for international projects.
Q: Can you provide original mill test certificates and accept third-party inspection before shipment?
A: Yes. Every shipment includes an original mill test certificate documenting chemical composition and mechanical properties, traceable to the coil heat number. We welcome SGS, BV, or Lloyd’s Register inspection at our facility before container loading — the inspection cost is typically borne by the buyer, but we coordinate scheduling and provide full access to test records.
Q: What is the minimum order quantity for custom sizes outside your standard 2,800+ specifications?
A: Our standard catalog covers 19×19mm to 800×800mm with 1–30mm wall thickness at a 5-ton MOQ. For non-standard dimensions requiring custom forming rolls, minimum orders depend on the tooling complexity and steel grade — typically higher than standard specs. We provide custom tooling quotes and lead times upon receipt of detailed drawings.
Q: When should I specify galvanized versus black painted finish for outdoor structural applications?
A: Hot-dip galvanized finish is recommended for outdoor applications exposed to weather, coastal salt air, or industrial corrosion environments — scaffolding, sound barriers, and solar mounting structures benefit from the zinc coating’s sacrificial protection. Black painted or bare finish suits indoor structural frames where fireproofing or intumescent coating will be applied on-site, or where the final paint system is specified by the project architect.
Q: Do your CE and ISO certificates meet EU and Singapore import requirements without customs delays?
A: Our CE certification under EN 10210 and EN 10219 includes the declaration of performance required under the EU Construction Products Regulation, and our Singapore FPC approval satisfies Building and Construction Authority requirements. ISO 9001:2015 covers the quality management system. These documents, combined with the mill test certificate and certificate of origin, clear customs in EU, North American, and Southeast Asian ports without delay when submitted with the shipping documentation.
Request Your ASTM A500 Square and Rectangular Steel Tube Quotation
Send your section dimensions, wall thickness, steel grade, quantity, and destination port to receive pricing with mill test certificates and production lead time.
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
