Product Overview

Our Q345 ERW carbon steel square tubes are manufactured using advanced Electric Resistance Welding (ERW) technology and high-quality hot-rolled steel coils, providing excellent structural strength, dimensional accuracy, and cost-effective performance. Designed for demanding construction, infrastructure, and industrial applications, these welded square steel pipes offer reliable mechanical properties and outstanding fabrication versatility.

Q345 steel is a low-alloy high-strength structural steel widely used in building construction, machinery manufacturing, steel structures, transportation equipment, and engineering projects. Compared with ordinary carbon steel grades, Q345 provides higher yield strength and improved load-bearing performance while maintaining excellent weldability and formability.

Manufactured in accordance with international standards, including JIS, KS, ASTM, and GB specifications, our ERW square steel tubes are available in a wide range of sizes, wall thicknesses, and surface finishes to meet the requirements of global construction and industrial projects.

Material Details

Q345 ERW Carbon Steel Square Tube

• Chemical Composition: ≤0.20%C, ≤0.50%Si, 1.00–1.60%Mn, ≤0.035%P, ≤0.035%S

• Equivalent Grades: JIS G3106 SM490A / SM490B, KS D3515 SM490, EN S355JR, ASTM A572 Grade 50 (Approximate Equivalent)

• Standards: GB/T 6728, JIS G3466, KS D3568, ASTM A500

• Mechanical Properties: Yield Strength: ≥345 MPa, Tensile Strength: 470–630 MPa, Elongation: ≥21%

• Material Characteristics: It offers high structural strength, excellent weldability, and good impact toughness, making it suitable for heavy-duty structural applications.

Core Features

✅ High Strength Structural Performance: Q345 steel offers significantly higher yield strength than standard carbon steel grades, making it suitable for load-bearing structures and engineering projects.

✅ Precision ERW Manufacturing: Advanced Electric Resistance Welding technology ensures consistent weld quality, dimensional accuracy, and reliable mechanical performance.

✅ Excellent Weldability: The controlled chemical composition allows easy welding, fabrication, and assembly without compromising structural integrity.

✅ Cost-Effective Construction Material: ERW square tubes provide an economical solution for structural applications while maintaining excellent strength and durability.

✅ Good Surface Quality: Hot-rolled steel combined with precision forming delivers smooth surfaces and uniform dimensions suitable for fabrication and coating processes.

✅ Versatile Industrial Applications: Widely used in steel structures, building frameworks, machinery manufacturing, warehouses, transportation equipment, agricultural systems, and infrastructure projects.

Why Choose Our Q345 ERW Square Steel Tubes?

ISO 9001 Certified Quality Control: Each production batch undergoes dimensional inspection, weld testing, chemical composition analysis, and mechanical property verification to ensure compliance with international standards.

Wide Range of Sizes: Available in various square dimensions, wall thicknesses, and lengths to meet different structural and engineering requirements.

Custom Processing Services: We provide cutting, punching, drilling, galvanizing, painting, beveling, and other fabrication services according to customer specifications.

Factory-Direct Supply: Our efficient production facilities allow us to offer competitive pricing, stable production capacity, and reliable delivery schedules.

Global Export Experience: Our ERW carbon steel square tubes are widely supplied to construction, infrastructure, industrial manufacturing, and engineering projects worldwide.

Frequently Asked Questions (FAQ)

Q: What is ERW steel tubing?

A: ERW (Electric Resistance Welded) steel tubing is produced by forming steel strip into a tube and welding the seam using electrical resistance heat without additional filler material.

Q: What are the advantages of Q345 steel compared with Q235 steel?

A: Q345 offers significantly higher yield strength and better load-bearing performance, making it more suitable for structural engineering, heavy-duty frameworks, and large construction projects.

Q: Can Q345 ERW square tubes be galvanized?

A: Yes. Hot-dip galvanizing and pre-galvanized finishes are available to improve corrosion resistance for outdoor and exposed environments.

Q: What industries commonly use Q345 square steel pipes?

A: They are widely used in building construction, steel structures, bridges, machinery manufacturing, warehouses, transportation equipment, and infrastructure projects.

Q: Do you offer custom sizes and lengths?

A: Yes. We provide custom dimensions, wall thicknesses, cut lengths, and fabrication services according to customer drawings and project requirements.

Q: Can you provide material certificates?

A: Yes. Mill Test Certificates (MTC), Material Test Reports (MTR), and third-party inspection reports can be supplied upon request.

Q: What is the delivery time?

A: Standard specifications are typically available within 7–15 days, while custom orders generally require 15–30 days depending on quantity and processing requirements.