Welcome to ALLLAND Steel Pipe Co., Ltd.
Welcome to ALLLAND Steel Pipe Co., Ltd.
ALLLAND Steel Pipe Supply
Welcome to ALLLAND Steel Pipe Manufacturing.JIS G3444 STK400 Steel Pipe is a structural carbon steel pipe that complies with Japanese Industrial Standards, with a minimum tensile strength of 400 MPa. It is widely used in building frames, steel structures, scaffolding, and engineering facilities. ALLLAND supplies STK400 steel pipes in a variety of specifications and offers custom sizing, test reports, and export services.
Alllandsteel is a steel pipe manufacturer based in China with 25 years of experience.
The facility spans 22,000 square meters, represents a RMB 700 million investment, and operates four production lines (JCOE, ERW, SMLS, SSAW) alongside five coating lines.
With an annual production capacity of 250,000 tons, the factory covers specifications ranging from Ø406 to Ø1524 and holds multiple international certifications (API/ASTM/EN/ISO/JIS). Focused on steel pipes, creating value for you!
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JIS G3444 STK400 steel pipe is a carbon steel structural pipe that complies with Japanese standards and is specifically designed for general engineering and construction applications.
This steel pipe conforms to the JIS G3444 standard for carbon steel structural pipes and is widely used in building frames, scaffolding systems, bridges, foundations, and various steel structure projects.
STK400 is one of the most commonly used grades in the JIS G3444 system, offering a combination of good strength, weldability, and cost-effectiveness.
O.D.:
21.7 mm – 609.6 mm (common standard range)
Up to ~700 mm+(depending on mill capability / custom order)
W.T.:
2.0 mm – 22.0 mm
Length:
6-12 m, available in fixed or multiple lengths; custom lengths per project requirements.
Manufacturing:
Seamless / ERW / Welded / Hot-finished
Standards:
JIS G3444
Steel Grade:
STK400
Tube Ends& Surface Treatment:
Square, Chamfered; Black Skin, Pickled, Painted/Oiled for Rust Prevention
Material Type:
Carbon Steel Structural Tube
STK: Steel Tube for Structural use
400: Minimum tensile strength approximately 400 MPa
STK400 is widely chosen in global structural projects because:
✔ Stable mechanical performance
✔ Easy fabrication and welding
✔ Cost-efficient material solution
✔ Compatible with galvanizing and coatings
✔ Suitable for international engineering standards
STK400 is a low-carbon structural steel designed for excellent weldability and formability.
| Element | Content |
| Carbon (C) | ≤ 0.25% |
| Silicon (Si) | – |
| Manganese (Mn) | – |
| Phosphorus (P) | ≤ 0.040% |
| Sulfur (S) | ≤ 0.040% |
| Property | Value |
| Yield Strength | ≥ 235 MPa |
| Tensile Strength | ≥ 400 MPa |
| Elongation | ≥ 23% |
| Outside Diameter (OD) (mm) | Wall Thickness (WT) (mm) | Theoretical Weight (kg/m) |
|---|---|---|
| 21.7 | 2.0 | 0.97 |
| 27.2 | 2.0 | 1.24 |
| 34.0 | 2.3 | 1.80 |
| 42.7 | 2.3 | 2.29 |
| 48.6 | 2.3 | 2.63 |
| 60.5 | 3.2 | 4.43 |
| 76.3 | 3.2 | 5.62 |
| 89.1 | 3.2 | 6.60 |
| 101.6 | 4.0 | 9.75 |
| 114.3 | 4.5 | 12.50 |
| 139.8 | 4.5 | 15.40 |
| 165.2 | 5.0 | 20.10 |
| 190.7 | 6.0 | 27.80 |
| 219.1 | 6.0 | 32.00 |
| 273.0 | 6.0 | 40.00 |
| 323.9 | 6.0 | 47.50 |
| 355.6 | 8.0 | 67.00 |
| 406.4 | 8.0 | 77.00 |
| 508.0 | 9.0 | 110.00 |
| 609.6 | 10.0 | 150.00 |
✔ Logic for Selecting Wall Thickness
STK400 is a medium-strength structural carbon steel tube widely used in non-pressure structural systems in construction and civil engineering projects around the world.
These are the STK400’s most critical application areas worldwide.
When ALLLAND supplies the STK400 for structural projects, its focus is not merely on “manufacturing steel pipes,” but on ensuring material traceability, consistent performance, precise dimensions, reliable welding, and compliance with engineering acceptance standards.
| Item | STK400 | STK490 |
| Strength | Medium | High |
| Yield Strength | ≥235 MPa | ≥315 MPa |
| Tensile Strength | ≥400 MPa | ≥490 MPa |
| Weldability | Excellent | Good |
| Formability | Very good | Medium |
| Cost | Lower | Higher |
| Main Use | General structures | Heavy structures |
| Item | STK400 (JIS G3444) | ASTM A500 |
| Standard | Japan (JIS) | USA (ASTM) |
| Type | Structural carbon steel pipe | Structural steel tubing |
| Yield Strength | ≥235 MPa | Grade B: ≥315 MPa / Grade C: ≥345 MPa |
| Tensile Strength | ≥400 MPa | 400–450 MPa (Grade B/C varies) |
| Weldability | Excellent | Very good |
| Formability | Very good | Good |
| Application | General building structures | Structural steel frames, buildings |
| Market Use | Asia projects | North America / global projects |
ALLLAND Steel Pipe provides high-quality steel pipes for construction and industrial projects, featuring a comprehensive range of specifications, strict quality control, and a reliable global supply chain.
STK400 is a structural carbon steel pipe under JIS G3444 standard, used for building structures, scaffolding, and general engineering applications.
No. STK400 is a structural steel tube, not designed for high-pressure fluid or gas transportation.
STK400 is generally considered similar to:
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