Description
Factory-direct ERW square tubes — Each batch is measured on our in-house calipers before loading, ensuring wall thickness stays within ±1% of the ordered ASTM A500 specification.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | ASTM A500 ERW Square Steel Tube |
| Product Type | Welded Square Steel Tube (ERW) |
| Steel Grade | Q195, Q235, Q235B, Q345, Q345B, SS400, ASTM A500, SGCC, CGCC |
| Standard | ASTM, JIS, ISO 9001, TISI |
| Section Shape | Square |
| Size Range | 20×20 mm – 200×200 mm |
| Wall Thickness | 1.5 – 30 mm |
| Length | 1 – 12 m |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Cold Rolled / Galvanized Coating |
| Tolerance | ±1% |
| Ends | Plain |
| Oiled or Non-oiled | Non-oiled |
| Processing Services | Welding, Punching, Bending, Decoiling, Cutting |
| Application | Construction Structure, Boiler, Fluid Transport, Gas Pipeline, Oil Pipeline, Hydraulic Systems, Drill Pipe, Chemical Fertilizer Equipment, Structural Frames |
| MOQ | 25 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, bridge support structures |
| Industrial Machinery | Hydraulic cylinder bodies, equipment frames, conveyor structures |
| Oil & Gas / Fluid Transport | Pipeline supports, gas distribution lines, chemical fertilizer plant piping |
| Steel Fabrication | Structural columns, beam-to-column connections, welded assemblies |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A 0.3 mm negative deviation on an ERW square tube can trigger rejection at destination customs or fail on-site caliper checks.
When sourcing an ASTM A500 ERW Square Steel Tube Supplier, buyers often discover that mill test certificates look clean on paper, but physical measurements at the receiving warehouse tell a different story. Rounded corners, inconsistent weld seams, and wall thickness drifting beyond ±1% tolerance create cascading delays — re-inspection fees, container demurrage, and in worst cases, full container returns. [NEED_CITE: dimensional tolerance requirements for cold-formed structural hollow sections]
Matching ERW Square Tubes to Structural and Industrial Loads
An ASTM A500 ERW Square Steel Tube in Q235B or Q345B grade delivers predictable load-bearing behavior for building frames and scaffolding, where flat surfaces enable clean bolted or welded connections. The 20×20 mm to 200×200 mm side-length range covers everything from light-duty machinery guards to heavy structural columns, while wall thicknesses up to 30 mm handle high-stress zones without switching to seamless alternatives. Galvanized coating extends service life in outdoor or humid environments, reducing maintenance cycles for infrastructure projects.
Engineering Compliance and Certification Requirements
Structural applications demand traceability from heat number to final dimension. ASTM A500 ERW Square Steel Tube orders destined for regulated markets require mill test certificates showing chemical composition and mechanical properties per standard, with third-party inspection (SGS/BV) available for projects mandating independent verification. TISI certification supports Southeast Asian imports, while ISO 9001 documentation satisfies quality management audits. [NEED_CITE: ASTM A500 structural tube certification requirements for international projects]
Steel Grade Selection and ERW Weld Integrity
Q195 and Q235 grades serve general structural and fluid transport roles where moderate yield strength suffices. Q345 and Q345B step up to higher load-bearing capacity for heavy frames and bridge components. The ERW process creates a longitudinal weld seam through electric resistance heating, producing a clean joint suitable for pressures and loads typical in construction and machinery — without the cost premium of seamless alternatives. Cold rolled surface finish provides dimensional precision for architectural applications, while galvanized coating adds zinc-layer corrosion protection for outdoor exposure. Wall thickness tolerance of ±1% ensures theoretical weight calculations match actual delivered mass, preventing budget overruns on tonnage-based contracts.
Hidden Costs of Unverified ERW Square Tube Procurement
Pricing that undercuts the market by 10–15% often signals negative tolerance stacking, substandard weld seams, or missing certification. An ASTM A500 ERW Square Steel Tube Supplier shipping without proper MTC documentation risks customs holds, while tubes failing dimensional checks on arrival force costly rework or replacement. Structural frames built from off-spec material face engineering liability exposure long after project handover. [NEED_CITE: consequences of non-compliant structural steel in construction projects]
Why Project Buyers Source ERW Square Tubes from SD XJY Pipe
Our in-house physical and chemical laboratory tests every production batch for dimensional accuracy, weld integrity, and chemical composition before release. With 2,800+ specifications in inventory, we fulfill mixed-size orders without forcing buyers to split procurement across multiple mills. Full international certifications — ISO 9001, TISI, JIS compliance, and SGS/BV third-party verification — clear customs in 50+ destination countries. Professional container loading with anti-bending measures prevents surface damage and dimensional distortion during ocean transit. Custom cutting, punching, and bending services reduce on-site fabrication time for contractors.
Documentation & Compliance
- Mill test certificate documenting Q235B/Q345B chemical composition and mechanical properties per ASTM A500 for each heat number
- TISI certification supporting Southeast Asian market customs clearance for ERW square tubes
- ISO 9001 quality management certificate covering production and inspection processes
- SGS or BV third-party inspection report available upon request for project-specific verification
- Material traceability from steelmaking heat number through final dimensional inspection
- Complete export documentation set: packing list, bill of lading, certificate of origin
Packaging, Loading & Delivery
- ERW square tubes bundled with steel strips and edge protectors to preserve galvanized coating during ocean transit
- Cold rolled surface tubes wrapped in waterproof paper with steel frame support for 6–12 m lengths
- Container loading optimized for 20×20 mm to 200×200 mm profiles, maximizing weight utilization while preventing bending
- Custom cutting to project-specific lengths within 1–12 m range, reducing on-site waste
- Heat number and steel grade stenciled on each tube for site traceability
- FOB, CIF, and DDP shipping terms available with door-to-door logistics coordination
Requesting a Quotation for ASTM A500 ERW Square Tubes
Submit your required side dimensions, wall thickness, steel grade, surface treatment preference, and destination port to receive a detailed quotation with unit pricing, production lead time, and mill test certificate confirmation. Non-standard sizes and mixed-container orders receive custom loading plans within 12 hours.
Get Your ASTM A500 ERW Square Tube Quote with Mill Test Certificate
Send your specifications, steel grade, and quantity to receive pricing and certification documentation within 12 hours.
Company: Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxjypipe.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxjypipe.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: What is the difference between Q235B and ASTM A500 Gr.B for ERW square tubes?
A: Q235B is a Chinese standard grade with minimum yield strength of 235 MPa, while ASTM A500 Gr.B is the US equivalent commonly specified for structural applications. Both grades serve similar load-bearing functions, and our mill test certificates document the specific chemical composition and mechanical properties for your ordered grade.
Q: Can you produce non-standard sizes outside the 20×20 mm to 200×200 mm range?
A: Yes, we offer custom non-standard dimensions beyond our standard inventory range. Submit your required side length, wall thickness, and length specifications for a custom production quote with typical lead times.
Q: What is the difference between cold rolled and galvanized surface treatment?
A: Cold rolled finish provides precise dimensional tolerance and smooth surface appearance for indoor or architectural applications. Galvanized coating adds a zinc layer for corrosion resistance, making it suitable for outdoor exposure, humid environments, or underground installations.
Q: Do you provide third-party inspection for ASTM A500 ERW square tubes?
A: Yes, SGS and BV third-party inspections are available upon request. We coordinate the inspection schedule with your designated surveyor and provide the inspection report alongside our mill test certificate before shipment.
Q: How do you prevent damage to galvanized square tubes during container loading?
A: Galvanized tubes are bundled with steel strips and fitted with edge protectors to preserve the zinc coating. We use professional loading plans that distribute weight evenly and prevent tube-to-tube contact, reducing the risk of surface scratches or coating damage during ocean transit.
