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JIS 3101 SS400 HOLLOW SECTION

Products Description

JIS G 3101: A standard for general structural rolled steel in Japanese industrial standards, covering material requirements (such as chemical composition and mechanical properties).

SS400: A steel grade under this standard, with a tensile strength of 400 MPa, it is widely used in structural fields such as construction and machinery.

Hollow profiles: Usually refer to square tubes, rectangular tubes or round tubes, etc., and may follow profile standards such as JIS G 3466 (Welded square and rectangular steel tubes) or JIS G 3444 (carbon steel tubes for structural use).
Material characteristics

Chemical composition (JIS G 3101 SS400) :
Carbon (C) : ≤0.29%
Manganese (Mn) : ≤1.40% (adjusted according to thickness)
Phosphorus (P), sulfur (S) : ≤0.050% (Low sulfur and phosphorus to ensure weldability)

Mechanical properties:
Yield strength: ≥245 MPa
Tensile strength: 400-510 MPa
Elongation: ≥17% (when thickness ≤16mm)
Profile standard (taking JIS G 3466 as an example)

Size specification:
Square tube/rectangular tube: Side length 20×20mm to 400×400mm, wall thickness 1.0-16mm.
Round pipes: The range of outer diameter and wall thickness is determined according to specific standards.

Manufacturing process:
High-frequency welding (HFW) or cold bending forming is suitable for medium and thin-walled pipes.
The hot rolling process is used for thick-walled tubes to ensure strength.

Performance and Application

Advantages:
High cost performance, easy to process and weld.
It is widely used in building frames, conveying equipment, mechanical parts, etc.

Limitations:
The corrosion resistance is average and surface treatment (such as galvanizing and painting) is required.
It has poor low-temperature toughness and is not suitable for extremely cold environments.

Processing and treatment

Welding: It is necessary to control the input heat to avoid embrittlement of the heat-affected zone. Preheating is recommended for thick-walled pipes.

Surface treatment: Choose galvanization or coating according to the environment to enhance corrosion resistance.

Comparison of international standards

China GB/T 6728: Similar to the standard of cold-formed hollow section steel, material Q235 is benchmarked against SS400.

ASTM A500 of the United States: Covers carbon steel structure pipes, Grade B has performance similar to SS400.
European EN 10219: Cold-formed welded hollow profiles, with material S235JRH comparable.

Precautions

Selection basis: Choose the wall thickness and cross-sectional shape based on the load and environment.
Quality inspection: Appearance inspection, tensile test and bending test in compliance with JIS standards are required.

Typical application scenarios
Building structure (roof trusses, supports)
Frames of mechanical equipment and rollers of conveying systems
Vehicle chassis components and temporary structural supports

Summary

JIS G 3101 SS400 hollow profiles combine the advantages of material and profile standards and are an economical and efficient structural solution. When making the correct selection, it is necessary to comprehensively consider the standard requirements, environmental factors and processing techniques to ensure the structural safety and durability. In actual procurement, the material standard (JIS G 3101) and the profile standard (such as JIS G 3466) should be clearly defined to avoid confusion.