Best-selling seamless steel pipe specification

Seamless steel pipes (SMLS pipes) are widely used across various industries, with their specifications varying based on application, industry standards, and regional demand. Based on market research and industry insights from Union Steel Industry Co., Ltd. in 2025, the following are the most sought-after seamless steel pipe specifications.

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1. 20# Seamless Steel Pipe

Material: High-quality carbon structural steel (20#) with good overall performance, easy processing, and excellent weldability.

Applications: Used in mechanical parts, hydraulic cylinders, bearings, and fluid transportation.

Features: Offers a high cost-performance ratio, making it one of the most in-demand seamless steel pipes.

2. 45# Seamless Steel Pipe

Material: Medium carbon steel (45#) known for high strength, hardness, and good machinability.

Applications: Commonly used in manufacturing gears, shafts, and connecting rods.

Features: Excellent mechanical properties and widespread application across various industries.

3. 16Mn Seamless Steel Pipe

Material: Low alloy structural steel (16Mn) with high strength and toughness.

Applications: Frequently used in high-pressure vessels, pipelines, and bridges.

Features: Outstanding performance under harsh working conditions, making it a preferred choice for critical applications.

4. Small & Medium Diameter Seamless Steel Pipes

Specifications: Outer diameter: 50mm – 150mm, Wall thickness: 4mm – 10mm.

Applications: Found in fluid transportation, mechanical structures, precision instruments, construction, chemicals, and the automotive industry.

Features: High dimensional accuracy and smooth surface finish, ensuring efficient performance in precision applications.

5. Large Diameter Seamless Steel Pipe

Specifications: Outer diameter: 219mm – 720mm, Wall thickness: 10mm – 30mm.

Applications: Used in oil and gas pipelines, marine engineering, water conservancy projects, and large structural components.

Features: Superior pressure resistance, making it ideal for heavy-load applications. With growing infrastructure projects, demand for large-diameter seamless pipes is increasing steadily.

Conclusion

Seamless steel pipes, whether small, medium, or large in diameter, remain best-selling due to their versatility and high market demand. Additionally, factors such as brand influence, technological advancements, and expanding application scenarios drive the seamless pipe industry's growth.

Apart from the common specifications mentioned above, some specialized seamless steel pipes are also gaining popularity due to their specific applications:

API 5L pipeline steel pipes – Used for oil and natural gas transportation.

GB/T 8162 structural seamless pipes – Designed for general structural and mechanical use.

GB/T 8163 fluid seamless pipes – Used for conveying water, oil, gas, and other fluids.

The demand for best-selling seamless steel pipes is subject to fluctuations based on market supply, industry trends, and emerging applications. Businesses should make purchasing decisions based on actual needs and thorough market research.