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For Structural Construction, Carbon Steel Seamless Tube Q345B, 6m Length, Square/Rectangular Custom, Mill Test Report
Product Spotlights
High-strength Q345B seamless tube with 6m length, customizable square/rectangular profiles, and Mill Test Report included. ISO9001 certified, suitable for structural construction. Available in black, painted, or galvanized finish. Large production capacity and global export experience ensure reliable supply.
Negotiable
MOQ: 1 Ton (Price negotiable depending on order volume and customization)
Key Specifications
Get Latest Price
Material:
Other, Carbon Steel Q345B
Surface Treatment:
Other, Black / Painted / Galvanized (optional)
Shape:
Square / Rectangular (Custom)
Payment & Shipping
Payment Methods:
Port of Shipment:
Qingdao Port
Delivery Detail:
7 days
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Material
Other, Carbon Steel Q345B
Surface Treatment
Other, Black / Painted / Galvanized (optional)
Shape
Square / Rectangular (Custom)
Length
6 meters (standard, customizable)
Wall Thickness
Customizable (1.5mm – 20mm)
Application
Structural Construction
Standard
GB/T 8162, ASTM A519 (available upon request)
Certification
ISO9001
Test Report
Mill Test Report included
Delivery Condition
Seamless, Hot Rolled / Cold Drawn
As a professional manufacturer from Hemaokang Steel (Shandong) Co., Ltd., we are proud to present our Carbon Steel Seamless Tube Q345B – a premium solution for structural construction projects. With an annual export value of US$50 million to US$100 million and a team of 51–100 experienced employees, we ensure every tube meets rigorous quality standards. Our Q345B seamless tubes are available in 6-meter lengths, with square or rectangular custom shapes, and come with a complete Mill Test Report for traceability. Whether you need load-bearing columns, trusses, or framework components, our product delivers consistent strength and reliability.
Key Features & Technical Specifications
- High Strength & Durability: Q345B steel offers a minimum yield strength of 345 MPa, making it ideal for structural applications where load-bearing capacity is critical.
- Seamless Manufacturing: No welded joints – reduces the risk of weak points and ensures uniform wall thickness, improving overall structural integrity.
- Customizable Shapes: Available in square and rectangular profiles, with dimensions tailored to your project requirements (e.g., side lengths from 20x20mm to 400x400mm, wall thickness from 1.5mm to 20mm).
- Standard Length & Cutting Service: Supplied in 6-meter lengths as standard; we also offer cutting to exact specifications upon request.
- Mill Test Report Included: Every batch is accompanied by a detailed test report covering chemical composition, mechanical properties, and dimensional accuracy, ensuring full traceability.
- Surface Treatment Options: Choose from black (as-rolled), painted (anti-corrosion coating), or hot-dip galvanized for enhanced corrosion resistance in harsh environments.
- ISO9001 Certified Quality Management: Our production process is ISO9001 certified, guaranteeing consistent quality control from raw material sourcing to final inspection.
| Parameter | Specification |
|---|---|
| Material Grade | Q345B (equivalent to S355JR, A572 Gr.50) |
| Yield Strength (min) | 345 MPa |
| Tensile Strength | 470–630 MPa |
| Standard Length | 6 meters (custom lengths available) |
| Shape Options | Square, Rectangular (custom dimensions) |
| Wall Thickness Range | 1.5mm – 20mm |
| Surface Treatment | Black / Painted / Galvanized (optional) |
| Test Report | Mill Test Report (MTR) provided |
Benefits for Your Projects
- Reduced welding costs and improved safety – seamless tubes eliminate the need for longitudinal weld inspection.
- Faster installation – precise square/rectangular profiles fit easily into structural frames and connections.
- Lower total cost of ownership – high strength allows lighter sections without sacrificing safety, saving material and transportation costs.
- Full compliance with international standards – our Q345B tubes meet or exceed GB/T 8162 requirements and can be produced to ASTM A519 or EN 10210 upon request.
- Reliable supply chain – with an annual export value exceeding US$50 million, we have the capacity to fulfill large orders with consistent lead times.
Frequently Asked Questions (FAQ)
-
Q: What is the difference between Q345B and standard carbon steel like Q235?
A: Q345B has a higher yield strength (345 MPa vs. 235 MPa) and better toughness, making it suitable for structural applications requiring higher load-bearing capacity. -
Q: Can you provide custom sizes beyond the 6-meter length?
A: Yes, we can customize lengths from 1m to 12m, as well as specific square/rectangular dimensions. Please contact us with your requirements. -
Q: Do you have certification for the material?
A: Our factory is ISO9001 certified, and each shipment includes a Mill Test Report verifying chemical composition and mechanical properties. -
Q: Is the tube suitable for outdoor use?
A: Yes, with optional galvanized or painted surface treatment, the tube can resist corrosion in outdoor environments. For severe conditions, we recommend hot-dip galvanizing. -
Q: What is the minimum order quantity (MOQ)?
A: MOQ depends on size and shape. Typically, for standard 6m square tubes, MOQ is 10 tons. For custom sizes, please inquire. -
Q: How long does delivery take?
A: For standard products, delivery is 15–20 days after order confirmation. Custom orders may take 25–35 days. -
Q: Can you provide samples before mass production?
A: Yes, we can provide sample pieces (1–2 meters) at cost, with shipping charges applicable. -
Q: Which payment terms do you accept?
A: We accept T/T, L/C, and other negotiable terms. For first-time clients, a 30% deposit is typical.
Why Choose Hemaokang Steel?
Founded in 2025, Hemaokang Steel (Shandong) Co., Ltd. has quickly become a trusted supplier in the global steel market. With an annual export value of US$50 million – US$100 million and a dedicated team of 51–100 employees, we serve customers across North America, South America, Europe, Southeast Asia, Africa, Oceania, the Middle East, and Asia. Our commitment to quality is backed by ISO9001 certification and a rigorous Mill Test Report for every batch. When you choose our Q345B seamless tubes, you benefit from years of industry expertise, competitive pricing, and reliable after-sales support. Contact us today to discuss your structural construction requirements – we are ready to support your next project with custom solutions and on-time delivery.
Send Inquiry to This Supplier
1Yr
Year Established
2025
Annual Export Value
US$50 Million - US$100 Million
Total Employees
51 - 100 People
Product Certifications
ISO9001
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