🟦 Product Overview

Structural Seamless Pipes under GB/T 8162 and EN 10210 are designed for mechanical structures, engineering frameworks, machinery, construction, and load‑bearing applications.

These pipes offer:

• High strength
• Excellent toughness
• Uniform wall thickness
• Superior performance under dynamic and static loads

They are widely used in steel structures, mechanical parts, construction frameworks, bridges, towers, machinery manufacturing, and other engineering applications.

🟦 Standards

GB/T 8162 — Seamless Steel Pipes for Structural Purposes

• Chinese national standard
• Covers hot‑rolled and cold‑drawn structural pipes
• Used for mechanical structures and engineering components

EN 10210 — Hot Finished Structural Hollow Sections

• European standard
• Covers hot‑finished seamless and welded structural tubes
• Includes S235JRH / S275J2H / S355J2H grades

🟦 Grades

GB/T 8162

• 10# / 20#
• Q345A / Q345B / Q345C
• 45# (for mechanical parts)

EN 10210

• S235JRH
• S275J2H
• S355J2H（most popular structural grade）

🟦 Product Specifications & Available Sizes

Outer Diameter (OD)

• 10–1200 mm

Wall Thickness (WT)

• 1.5–60 mm

Length

• 6 m / 12 m / custom

Manufacturing Methods

• Hot Finished Seamless (HFS)
• Cold Drawn Seamless (CDS)
• Normalized / Normalized Rolled

End Types

• Plain End
• Beveled End

🟦 Chemical Composition

GB/T 8162 (20# Steel Example)

Element	Content (%)
C	0.17–0.23
Mn	0.35–0.65
Si	0.17–0.37
P	≤ 0.035
S	≤ 0.035

EN 10210 (S355J2H Example)

Element	Content (%)
C	≤ 0.22
Mn	≤ 1.60
Si	≤ 0.55
P	≤ 0.030
S	≤ 0.030
N	≤ 0.012

🟦 Mechanical Properties

GB/T 8162 (20# Steel)

Property	Requirement
Tensile Strength	410–550 MPa
Yield Strength	≥ 245 MPa
Elongation	≥ 20%

EN 10210 (S355J2H)

Property	Requirement
Tensile Strength	470–630 MPa
Yield Strength	≥ 355 MPa
Elongation	≥ 22%
Impact Test	≥ 27 J @ −20°C

🟦 Physical Properties

Property	Value
Density	7.85 g/cm³
Thermal Conductivity	45–60 W/m·K
Magnetic	Yes

🟦 Manufacturing Processes

• Hot Rolling
• Cold Drawing
• Normalizing
• Annealing
• Ultrasonic Testing
• Eddy Current Testing
• Hydrostatic Testing

🟦 Primary Industry Usage

• Steel structures
• Mechanical engineering
• Construction frameworks
• Bridges & towers
• Machinery manufacturing
• Offshore structures
• General engineering applications

🟦 Why Use Structural Seamless Pipe

• High strength for load‑bearing structures
• Excellent toughness and reliability
• Uniform wall thickness for precision engineering
• Suitable for welding, bending, and machining
• Compliant with global structural standards

🟦 Why Choose WelSteels

• Full range of GB/T 8162 & EN 10210
• Hot‑finished & cold‑drawn options
• MTC 3.1 + third‑party inspection
• Export‑grade packaging & loading supervision
• Competitive pricing for engineering projects