Description
Factory-Direct ERW Rectangular Steel Tube Pricing — We roll SS400 rectangular hollow sections on our own ERW lines in Jinan and ship to port without trading margins, keeping your per-ton cost aligned with raw material fluctuations.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | SS400 ERW Rectangular Steel Tube |
| Product Type | Rectangular Hollow Section (ERW Welded) |
| Steel Grade | SS330, SS400, SS490, SPCC, SPCD, SPCE, Q195, Q235, Q345, S235JR, S355JR, ST37, ST42, ST52, S500, SPHC, DC01, QSTE, SAPH |
| Standard | JIS G3466, JIS G3131, EN 10219, GB/T 6728 |
| Section Shape | Rectangular |
| Size Range | 10mm×30mm – 600mm×800mm |
| Wall Thickness | 0.5mm – 20mm |
| Length | 1m – 16m or Customized |
| Technique | ERW (Electric Resistance Welded) |
| Surface Treatment | Bared / Black Painted / Galvanized / Oiled / Shop Primer and Shot Blasting |
| Tolerance | ±1% |
| Processing Service | Bending, Cutting, Decoiling, Punching, Welding |
| Invoicing | By Actual Weight |
| MOQ | 1 Ton |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, portal frames, mezzanine supports |
| Agricultural Machinery | Tractor chassis, harvester protective guards, irrigation structure frames |
| Construction Machinery | Crane boom sections, excavator cab frames, conveyor supports |
| Light Fabrication | Electric bicycle frames, warehouse shelving, furniture structures |
Why ±1% Tolerance Decides Whether Your Frame Fits on Site
A 5mm deviation on a 6-meter rectangular tube means re-cutting every piece before welding.
When structural frames are designed around precise node positions, out-of-tolerance SS400 ERW rectangular steel tube forces fitters to grind, re-cut, or even scrap members — burning labor hours that were never budgeted. We have watched MEP contractors on Middle East high-rise projects lose entire weekends because the hollow sections delivered did not match the shop drawings dimensionally. The root cause is rarely the designer; it is the mill running negative tolerance beyond what the standard allows, or a trader substituting a lower-grade section without documentation. [NEED_CITE: EN 10219 dimensional tolerance requirements for cold-formed hollow sections]
Matching SS400 Rectangular Sections to Structural and Fabrication Loads
SS400 under JIS G3466 sits in the mild structural steel range, making the SS400 ERW rectangular steel tube a default choice for non-critical load-bearing frames, equipment enclosures, and architectural supports where welding and forming are required. The ERW process produces a consistent longitudinal weld seam that handles bending and punching without the delamination risks seen in poorly welded alternatives. For projects spanning Southeast Asia and the Middle East, where JIS and EN grades are frequently specified side by side, we cross-reference SS400 against S235JR and Q235B during quotation so buyers avoid double-ordering during material substitution.
Engineering Compliance, Surface Protection, and Grade Selection
Rectangular hollow sections used in primary structures must comply with the dimensional and weld-seam requirements of EN 10219 or JIS G3466, depending on the specifying authority. In coastal or industrial atmospheres, galvanized or shop-primed finishes extend service life significantly compared to bare black tube, and our shot-blasting line prepares surfaces to Sa 2.5 before primer application. When projects demand traceability across heat numbers, we stamp each bundle with the heat code and steel grade so site inspectors can verify against the mill test certificate without opening every piece. [NEED_CITE: steel grade equivalence tables between JIS SS400 and EN S235JR]
Understanding SS400, ERW Welding, and Tolerance Behavior
SS400 is a Japanese Industrial Standard grade covering general structural applications, with carbon and manganese levels balanced for good weldability and moderate formability. Within the JIS family, SS330 offers lower strength for light framing, while SS490 steps up for heavier load paths — and our rolling schedule covers all three on the same ERW line, allowing mixed-grade container loading. The ERW process forms the tube from hot-rolled coil through continuous forming and electric resistance welding, producing a clean internal bead suitable for most structural uses. Wall thickness tolerance of ±1% means a 6mm nominal wall will measure between 5.94mm and 6.06mm — tight enough for structural calculation confidence without the premium of seamless processing. Surface options from oiled (short-term rust prevention during transit) to galvanized (long-term atmospheric protection) let buyers match the finish to the installation environment rather than over-specifying.
Hidden Costs When Tolerance, Grade, or Certification Falls Short
Ordering SS400 ERW rectangular steel tube based on price alone often surfaces costs later: negative tolerance beyond standard limits reduces actual load capacity, missing mill test certificates trigger customs holds at destination ports, and unverified weld seams fail during bending or punching operations. A single container of non-conforming tube can delay an entire structural package, forcing air-freight of replacement material or idle crew costs on site. [NEED_CITE: consequences of non-compliant steel imports on project schedules]
Procurement Confidence from Mill to Site
Our Jinan facility runs three ERW lines producing rectangular and square hollow sections across 2,800+ specifications, so your SS400 ERW rectangular steel tube rolls on the same equipment we use for domestic infrastructure contracts — no subcontracted quality variation. Every heat is tested in our in-house laboratory, and original mill test certificates travel with each shipment, listing chemical composition and mechanical results traceable to the heat number stamped on the bundle. For European-bound orders, our Lloyd’s CE certification under EN 10210 and EN 10219 clears customs without additional testing, and SGS or BV third-party inspection can be arranged before loading at buyer’s request. Custom lengths up to 16m, non-standard dimensions, and mixed-size container loading are handled by our export team, who optimize stowage to minimize freight cost per ton.
Documentation & Compliance
- Mill test certificate documenting SS400 chemical composition (C, Mn, P, S) and tensile test results per JIS G3466, traceable to heat number
- CE certificate under EN 10219 for S235JR and S355JR rectangular hollow sections shipped to European Union ports
- ISO 9001:2015 quality management certificate covering the full ERW rectangular tube production process
- SGS or BV third-party inspection report available upon request, covering dimensional checks, weld-seam quality, and surface finish
- Material traceability sheet linking each bundle to its heat number, rolling date, and test certificate
- Export customs documents including packing list, bill of lading, and certificate of origin formatted for destination port requirements
Packaging, Loading & Delivery
- SS400 rectangular tubes bundled with galvanized steel strips at intervals matched to the 1m–16m length range, preventing bundle shift during ocean transit
- Oiled or galvanized surface finishes protected with edge guards and waterproof wrapping to preserve coating integrity through port handling
- Container loading plans optimized for rectangular section geometry, fitting mixed sizes from 10×30mm to 600×800mm to maximize payload per 20ft or 40ft unit
- Custom cut lengths marked with heat number and steel grade stenciled on each piece for rapid site identification
- FOB, CIF, and DDP shipping terms available from Qingdao port, with door-to-door coordination for project sites inland
Starting Your SS400 Rectangular Tube Inquiry
Send your drawing list or specification sheet covering section dimensions, wall thickness, length, steel grade, surface finish, and destination port — we return a detailed quotation with per-ton pricing, typical production lead times, and the applicable mill test certificate format within one working day. For non-standard dimensions or mixed-grade container requirements, our technical team will propose a rolling or fabrication plan before you commit to a deposit.
Frequently Asked Questions
Q: Can SS400 rectangular tubes be substituted with S235JR or Q235B on the same project?
A: SS400, S235JR, and Q235B occupy similar strength ranges in their respective JIS, EN, and GB standards, and we provide cross-reference documentation during quotation so your engineer can approve substitution without re-specifying the entire order.
Q: What is the minimum order quantity for custom non-standard rectangular dimensions?
A: We accept trial orders starting from 1 ton, and our 2,800+ specification inventory covers most standard sizes from stock — custom dimensions outside the 10×30mm to 600×800mm range are quoted based on rolling minimums.
Q: How are surface treatment options selected for different installation environments?
A: Bare or oiled tubes suit indoor or short-term storage applications, galvanized finishes serve outdoor or coastal environments, and shop-primed with shot blasting prepares surfaces for final painting on structural frames.
Q: What documentation is provided for European Union customs clearance?
A: Shipments to EU ports include the CE certificate under EN 10219, mill test certificates, and export documents formatted for EU import requirements — our Lloyd’s certification covers both EN 10210 and EN 10219 hollow section standards.
Q: How is invoicing calculated when tolerance affects actual weight?
A: We invoice by actual weight measured at our mill after production, so you pay only for the steel that ships — the ±1% tolerance ensures minimal deviation from theoretical weight calculations.
Request Your SS400 ERW Rectangular Steel Tube Quotation
Submit your section dimensions, steel grade, quantity, and destination port to receive factory-direct pricing and mill test certificate samples within one working day.
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