Description
Factory-Direct Hot Rolled Square Tubes — Every batch ships with original mill test certificates covering Q195–Q460 chemistry and mechanical data, priced without trader markups.
Technical Specifications
| Parameter | Value |
|---|---|
| Designation | Q195-Q460 Hot Rolled Square Steel Tube |
| Product Type | Square Steel Tube |
| Steel Grade | Q195, Q235, Q235B, Q345, Q345B, Q460, SS330, SS400, SS540 |
| Standard | ISO 9001 certified; ASTM / EN / JIS applicable per grade |
| Section Shape | Square (also covers 40×60 mm rectangular variant) |
| Size Range | 100×100 mm side length |
| Wall Thickness | 0.5–200 mm |
| Length | 12 m (custom cutting available) |
| Technique | Hot Rolled |
| Surface Treatment | Hot Rolled / Non-Oiled |
| Tolerance | ±1% |
| Ends | Plain (custom processing available) |
| Application | Fluid Pipe, Boiler Pipe, Drill Pipe, Hydraulic Pipe, Gas Pipe, Steel Structures, Construction Frames, Machinery |
| MOQ | 5 Tons |
| Origin | Shandong, China |
Application Suitability
| Industry | Typical Applications |
|---|---|
| Construction & Infrastructure | Building frames, scaffolding systems, structural support columns |
| Industrial Machinery | Hydraulic cylinder bodies, drill pipe casings, heavy equipment chassis |
| Energy & Fluid Transport | Boiler tube assemblies, gas distribution pipelines, fluid conveyance manifolds |
What Wall-Thickness Tolerance Costs on a Structural Frame Order
A ±1% tolerance on a 200 mm wall hot rolled square tube means the difference between passing structural inspection and scrapping an entire container at the job site.
When global steel buyers source square tubes from fragmented suppliers, they routinely encounter inconsistent wall thickness across batches, unclear grade traceability, and missing certification that triggers customs holds. I have seen 100×100 mm square tubes arrive at Southeast Asian sites with end deformation and weld cracks because the supplier never verified cutting tolerances or loading support before sealing the container. The Hot Rolled Square Steel Tube Supplier you choose must guarantee dimensional consistency from the first piece to the last, backed by verifiable mill documentation. [NEED_CITE: EN 10219 dimensional tolerance requirements for hot formed structural hollow sections]
Matching Heavy-Duty Structural Loads in Construction and Machinery
Hot rolled square tubes in Q345 and Q460 grades deliver the yield strength needed for load-bearing columns and heavy machinery frames where thin-wall alternatives buckle under compression. The 0.5–200 mm wall range covers everything from light scaffolding to thick-wall hydraulic cylinders, while the ±1% tolerance ensures predictable weight calculations for crane load planning. As a Hot Rolled Square Steel Tube Supplier, we run in-house bending, cutting, and punching so your fabricator receives ready-to-weld sections without secondary shop delays.
Engineering Compliance and Certification Requirements
Structural frames in European markets require CE marking under EN 10210 for hot finished hollow sections, while North American projects reference ASTM A500 grade classifications. The non-oiled hot rolled surface accepts primer and galvanizing directly, but buyers must confirm whether their project specification demands mill-annealed or as-rolled condition before coating. Third-party inspection by SGS or BV verifies chemistry and mechanical properties against the declared grade, preventing the customs clearance failures that plague undocumented shipments. [NEED_CITE: ASTM A500 grade B and C mechanical property requirements]
Decoding Q-Series Grades and Hot Rolling Process
Q195 through Q460 represent a Chinese national standard grade progression where the number indicates minimum yield strength in MPa—Q235 yields at approximately 235 MPa, Q345 at 345 MPa, and Q460 at 460 MPa. Hot rolling produces a mill scale surface that must be removed before painting, but the process delivers superior dimensional accuracy for thick-wall sections compared to cold forming. The SS330–SS540 Japanese industrial grades overlap with Q-series equivalents, allowing cross-standard substitution when project documentation permits. Wall thickness up to 200 mm is achievable through hot rolling because the material remains ductile at forming temperatures, whereas cold-formed processes typically cap at 16 mm. [NEED_CITE: hot rolling versus cold forming wall thickness limitations]
Hidden Costs of Unverified Material and Missing Certificates
Ordering square tubes without confirmed grade equivalence between EN, ASTM, and GB standards risks structural rejection when the engineer’s calculation assumes a specific yield point. Certification gaps—missing CE marks for European sites or incomplete mill test certificates for customs—cause port holds that delay projects by weeks and incur demurrage charges. Negative tolerance abuse, where actual wall thickness falls below the declared minimum, reduces load capacity and triggers safety audits that halt construction. [NEED_CITE: steel grade equivalence tables between GB Q-series and EN S-series]
Why Source Hot Rolled Square Tubes From Our Mill
We operate three production lines running simultaneously with monthly capacity exceeding 20,000 tons, eliminating the broker margins that inflate prices from trading companies. Every heat number traces back to our in-house laboratory where three-stage inspection verifies chemistry before the billet is cast, during rolling, and after final sizing. Our inventory covers 2,800+ specifications including non-standard wall thicknesses, so your urgent 5-ton trial order ships from ready stock while custom 12-meter cuts go through our saw line within typical production lead times. We hold ISO 9001:2015, Lloyd’s CE certification under EN 10210/10219, and FPC factory production control—meaning your European buyer receives documentation that clears customs without supplementary testing. Professional export teams optimize container loading for 12-meter lengths, reducing per-ton freight costs on FOB and CIF shipments to 50+ countries.
Documentation & Compliance
- Mill test certificate documenting Q195–Q460 chemical composition and yield strength per declared standard, with heat number traceability
- CE certificate under EN 10210 for hot finished structural hollow sections, required for European construction projects
- ISO 9001:2015 quality management certificate covering the full production process from raw material to finished tube
- SGS or BV third-party inspection report verifying dimensional tolerance and mechanical properties before container sealing
- Material traceability report linking each bundle to its original heat number and rolling batch
- Complete customs documentation including packing list, bill of lading, and certificate of origin for the destination country
Packaging, Loading & Delivery
- Hot rolled square tubes bundled with steel strips and edge protectors to prevent surface damage during ocean transit, with non-oiled finish ready for immediate coating upon arrival
- 12-meter standard lengths loaded vertically in 20-foot and 40-foot containers using optimized stowage plans that maximize weight without exceeding port crane limits
- Custom cutting to project-specified lengths available before shipping, reducing on-site waste and cutting labor at the destination
- Each bundle marked with heat number, steel grade (Q235B, Q345B, etc.), and dimensional specifications for immediate site identification
- FOB, CIF, and DDP terms available with professional documentation handling for customs clearance in Southeast Asia, Middle East, Africa, and South America
- Consolidated multi-product loading available when your order includes plates, beams, or section steel alongside square tubes
Getting Your Quote and Mill Test Certificate
Submit your specifications including steel grade, wall thickness, quantity, and destination port to receive a competitive bulk quote with volume discount pricing within 12 hours. We provide sample sections and original mill test certificates for quality verification before you commit to a production order. Confirm your certification requirements—CE for European markets or ASTM for North American projects—and we include the corresponding documentation in your proforma invoice.
Request Factory-Direct Pricing and Mill Test Certificates
Send your hot rolled square tube specifications, steel grade, and target quantity to receive bulk pricing with original mill test certificates and third-party inspection options.
Shandong Xin Jiyuan Special Steel Tube Co., Ltd
Website: www.sdxinjiyuan.com
Tel: +86 531 8573 6315
Mobile/WhatsApp/WeChat: +86 188 5315 7756
Email: admin@sdxinjiyuan.com
Address: No.11889, Jingshi West Road, Lulian Group, Jinan City, Shandong Province, China
Frequently Asked Questions
Q: What steel grades are available and how do they compare across EN/ASTM/GB standards?
A: We supply Q195, Q235, Q235B, Q345, Q345B, Q460, SS330, SS400, and SS540 grades. The Q-series follows Chinese GB standards where the number indicates minimum yield strength in MPa. These grades have equivalents in EN S-series and ASTM A500 classifications, and we provide grade equivalence documentation for your engineer’s approval.
Q: Can you provide third-party inspection and mill test certificates for customs clearance?
A: Yes. Every batch ships with original mill test certificates showing chemical composition and mechanical properties. We also arrange SGS or BV third-party inspection before shipment for independent verification, which satisfies most customs and project compliance requirements worldwide.
Q: What is the MOQ for custom sizes and non-standard wall thickness?
A: The standard MOQ is 5 tons. For non-standard wall thickness outside our 0.5–200 mm range or custom lengths beyond 12 meters, we evaluate feasibility based on our production line capabilities and provide lead time estimates during quotation.
Q: How do you handle surface treatment options—hot rolled versus galvanized versus painted?
A: Our hot rolled square tubes ship with non-oiled mill scale finish, ready for immediate painting or galvanizing at your facility. If you require pre-galvanized or painted finish, we coordinate with our coating partners and include the additional processing in your quotation with extended lead time.
Q: What are the delivery terms and production lead time for bulk orders?
A: We offer FOB, CIF, and DDP terms. Ready stock in standard specifications ships within days of deposit receipt. Custom orders in non-standard sizes typically require typical production lead times, which we confirm in your proforma invoice based on current mill scheduling.
