What is your packaging method for export shipment?

We adopt standard export packaging. Steel strips are used to bundle the steel tubes tightly, and waterproof wrapping is applied to prevent moisture and rust during sea transportation. Custom packaging requirements can be negotiated.

Hot Rolled Q235B Carbon Structural Seamless Square Rectangular Steel Tube High Toughness for Building Structure & Support Frame

Name: Hot Rolled Q235B Carbon Structural Seamless Square Rectangular Steel Tube High Toughness for Building Structure & Support Frame
Brand: Jiangsu Changchen Materials Co., Ltd.
SKU: 1998906581

Jiangsu, ChinaJiangsu Changchen Materials Co., Ltd.

US$720.00

1-9 Tons

US$700.00

10-19 Tons

US$680.00

20+ Tons

Product profile

Customization

Available

After-sales Service

After-Sales Service Available

Type

Seamless

Model NO.

Hot Rolled Q235B seamless square tube

Technique

Hot Rolled

Material

Carbon Steel

Surface Treatment

Black

Usage

Machinery Industry, Construction & Decoration

Section Shape

Square

Surface

Black

MOQ

1 Ton

Tolerance

Standard Tolerance

Processing Service

Cutting, Bending

Application

Construction, Machinery Manufacturing, Equipment F

Transport Package

Steel Bundles with Straps, Plastic Strips

Specification

Thickness: 3-60mm, Side Size: 10-300mm

Trademark

OEM & ODM Acceptable

Origin

Jiangsu, China

HS Code

7304900000

Production Capacity

50000

Key features

Customized Sizes Available: Complete customized sizes and special wall thicknesses to meet specific project requirements.

Multiple Steel Grades: Supports Q235B, Q355B, 20#, and 45# carbon structural steel grades.

Superior Mechanical Strength: Seamless integral structure offers excellent torsion resistance and stable welding performance.

OEM & ODM Acceptable: Full customization from samples and designs is supported for various industries.

Strict Quality Control: 100% visual inspection with chemical composition and mechanical performance tests per batch.

Comprehensive Certifications: Mill Test Certificates (MTC) and inspection reports provided for third-party verification.

Fast Delivery for Stock Items: Conventional in-stock specifications can be delivered quickly upon order.

Diverse Manufacturing Processes: Available in Hot Rolled and Cold Drawn seamless forming with black or pickled surfaces.

Company profile

Fast DeliveryManagement CertificationR&D CapabilitiesQA/QC Inspectors

Jiangsu Changchen Materials Co., Ltd.

Jiangsu, China

CertifiedBusiness Type: Manufacturer/Factory & Trading Company CertifiedR&D Capacity: ODM Service Available CertifiedCustomization Options: Customization from Samples, Customization from Designs CertifiedExport Year: 1 Year CertifiedNearest Port: Shanghai PortAverage Response Time: ≤2.21h

AI-Powered supplier vetting

SummaryChangchen operates in metal materials, special steel, forgings, powder metallurgy, metal processing machinery, and cutting services. It reports customization from samples and designs, ODM availability, recent new-product development, CAD/PS-related R&D capability, and documented R&D inputs, outputs, reviews, verification, and validation. Production-related evidence includes valid contracts with associated subcontractors, inventory capability, raw-material traceability, and 100% finished-product inspection; however, only one quality inspector is reported. The supplier states that products can meet several national and international standards, but no specific certifications are identified. Overseas support is limited: there are no overseas agents or branches, warehouses, showrooms, or stated overseas service countries. Lead time is reported as within 15 working days in both peak and off-season. Financial information is insufficient for a reliable assessment, and no customer cases are provided.

Supplier typeThe supplier’s stated business scope covers sales of metal materials and products, special steel, forgings, powder metallurgy products, recycled resources, metal-processing machinery, and metal cutting services. This supports classification as a metal-material and metal-processing supplier, although the slices do not establish a more specific legal or manufacturing classification.

R&D capabilityThe supplier reports new products during the past year, R&D responsibilities covering new-product development, design drawings, production technical support, and customer specifications, plus CAD and PS software capability. It also has auditable R&D design-input, output, review, verification, and validation documentation, although no SDK is available.

Production capacityProduction-related evidence includes sawing and cutting equipment, metal cutting and processing activities, inventory capability, valid manufacturing contracts with associated subcontractors, raw-material traceability, and 100% finished-product inspection. The reported quality-control staffing is one inspector, while supplier-management procedures have no records, so capability is supported but operational depth is limited.

Customization capabilityChangchen explicitly provides customization from samples and designs, offers ODM services, and states that customized services can be developed according to customer requirements. Its R&D role includes preparing product specifications for customer approval, providing direct evidence of customer-oriented customization capability.

Product Q&A

Q:What are the advantages of seamless square rectangular tubes compared with welded tubes?

Seamless square and rectangular steel tubes are integrally formed without welding seams. The overall structure is more uniform, with higher strength, better torsion resistance and stronger bearing capacity. It is not easy to crack or deform under heavy load, which is more suitable for high-strength structural engineering and mechanical supporting scenarios compared with welded pipes.

Q:What steel grades can you provide for seamless square tubes?

We support full series of carbon structural steel grades, including Q235B, Q355B, 20# and 45#. Both hot rolled and cold drawn seamless processes are available, and all specifications can be customized according to customer demands.

Q:Can you produce non-standard sizes and fixed lengths?

Yes. We have complete production equipment to customize non-standard outer dimensions, special wall thickness and precise fixed cutting lengths. We can produce products strictly according to customer drawings and technical parameters.

Q:How do you ensure product quality and inspection standards?

All raw materials are selected from regular large steel mills. The whole production process is supervised and recorded. Each batch of products will pass chemical composition analysis and mechanical performance tests before shipment. Complete MTC certificates and inspection reports can be provided to support third-party testing.

Q:What is your delivery cycle?

Conventional in-stock specifications can be delivered quickly. For customized non-standard products, the production cycle is about 7-15 working days after receiving the deposit. The specific delivery time depends on order quantity and production schedule.