Product Description

Seamless square tube is a hollow structural steel profile with a square cross-section, made from seamless round pipes via precision cold drawing, cold forming or hot extrusion. It has no welded seams, uniform wall thickness, high dimensional accuracy and excellent mechanical performance, with good bending, torsion and compression resistance. Available in carbon steel, alloy steel and stainless steel, it is widely used in construction, machinery manufacturing, automotive and engineering fields, and we support customized sizes and surface treatments to meet specific needs.

Parameter

Product name	Seamless square steel pipe
Standard	AISI,ASTM,DIN,JIS,GB ,JIS,SUS,EN,etc
Steel Grade	API 5L、ASTM A213、A312、ASTM A269、ASTM A778、ASTM A789、 DIN 17456、ASTM A106、ASTM A53、ASTM A36、DIN 17457、DIN 17459 JIS G3459、JISG3463、GOS T9941、EN 10216、BS3605、GB13296 10#、20#、45#、Q235、Q345、Q195、Q215、Q345A、Q345B GR.B A135、P265TR1、P265TR2、STPT480、A106、GR.C, A210C ST35.8、ST45.8、ST52, ST37, ST37-2, DIN 1629 ST35, ST45, DIN 17175 ST35.8, DIN 17175 19Mn5
Wall Thickness	1-20mm
Length	1-12m
Type	Hot-rolled /Cold-rolled /Cold-drawing
Inspection	With hydraulic testing, eddy current, infrared test
Surface	Black painted, PE/PVC/PP coated, Galvanized, color coated, anti rust varnished,anti rust oiled, checkered, epoxy coating, etc.
Application	Seamless pipes are widely used in petroleum、chemical、medical、food、light industry、machinery、instrument and other industrial pipeline and mechanical structure parts and etc.

Application description

Widely applied in various fields due to its reliable performance: it is used in construction for structural frameworks, beams and columns; in machinery manufacturing for equipment frames and components; in automotive industry for chassis parts and support structures; and in engineering machinery, hydraulic systems, power facilities and logistics equipment that require high load-bearing capacity and stability, perfectly adapting to both indoor and outdoor working environments.

Production description

Solid square billet is heated, pierced, and hot rolled into a seamless hollow shell. The round shell is then cold drawn through a square die or passed through square-shaped rolls with a mandrel to form a square profile. Multiple cold drawing passes with intermediate annealing ensure precise outer dimensions, uniform wall thickness, and good corner radius. The final tube is straightened, cut to length, and inspected.

Shipping Packaging

For export, seamless square tubes are bundled with plastic end caps, wrapped in VCI paper and moisture-proof polyethylene, packed in wooden crates or on ISPM-15 pallets, secured with steel straps, and fitted with edge protectors. Labels include grade, dimensions, length, quantity, and heat number for safe sea freight.

Why Choose Us?

1.Factory Strength:Direct manufacturer with piercing mills, hot rolling lines, and precision cold drawing equipment for seamless square tubes, ensuring uniform wall thickness, tight corner radius, and consistent mechanical properties.

2.Quality Assurance:Strict control of dimensional tolerances (outer dimension ±0.5mm, wall thickness ±0.1mm), straightness, and surface finish; 100% eddy current or ultrasonic testing; compliant with ASTM A519, EN 10210-2, JIS G3445, GB/T 8162.

3.Certifications & Reports:Mill test certificates (MTC) with each shipment; third-party inspections (SGS, BV) and PMI test reports available upon request.

4.Customization & Service:Wide grade range (carbon steel, alloy steel, stainless steel), sizes from 20×20mm to 500×500mm, wall thickness 1.5–30.0mm, custom lengths, corner radii, and heat treatment (annealed, normalized) with fast lead times.

5. Export Packaging:Plastic end caps + VCI paper + moisture-proof wrapping + wooden crates/ISPM-15 pallets + steel strapping + edge protectors for safe sea freight and damage-free delivery.

FAQ

1. What size range can you produce for seamless square tubes?
Outer dimension: 20×20mm up to 500×500mm. Wall thickness: 1.5mm to 30.0mm. Length: up to 12m or custom. Corner radius can be tailored.

2. How do seamless square tubes compare to welded square tubes?
Seamless tubes have no weld seam, offering higher pressure resistance, uniform structure, and better performance in high-temperature or critical applications. Welded tubes are more cost-effective for general structural use.

3. Can seamless square tubes be supplied with heat treatment?
Yes. We offer annealed, normalized, or quenched & tempered conditions to meet your required hardness, strength, and ductility for forming or load-bearing applications.

CLIENT FEEDBACK

Has a professional foreign trade team and a well-established export service system. We have built long-term and stable cooperation relationships with customers from Southeast Asia, the Middle East, Africa, South America, and other regions.

CUSTOMER VISIT

We sincerely welcome global partners to contact us for mutual growth. With high-quality products and professional service, we look forward to working with you to create a prosperous future together.

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