📖 Steel Pipe Selection Guide | Why is STKR400 So Popular? Low-Carbon Steel Pipe Analysis!
When choosing structural steel pipes, STKR400 is a top choice for many construction and machinery manufacturers. It complies with JIS G3466 standards and is available in square, rectangular, and round pipe forms. But why is this steel pipe so widely used? What are the alternative materials? Let’s break it down!
📌 What is STKR400? Why is it so popular?
STKR400 is a low-carbon structural steel pipe commonly used in construction, mechanical equipment, steel frame supports, and industrial applications. It is available in black steel (uncoated) or galvanized (STKR400 galvanized round pipe / STKR400 galvanized square pipe) for enhanced weather and corrosion resistance.
🔸 Key Features of STKR400:
✔ Low carbon content (~0.20% C) for excellent ductility and weldability
✔ Yield strength ≥ 245 MPa, tensile strength ≥ 400 MPa, offering both rigidity and machinability
✔ Suitable for welding, cutting, and bending without cracking
✔ Used in building structures, mechanical frames, steel engineering, bridges, and support structures
📌 STKR400 Shapes & Applications:
🔸 Round Pipe (STKR400 Round Pipe / STKR400 Galvanized Round Pipe) → Used in steel structures, equipment pipelines, bridge supports
🔸 Square Pipe (STKR400 Square Pipe / STKR400 Galvanized Square Pipe) → Suitable for building frames, machinery supports, steel furniture
🔸 Rectangular Pipe → Ideal for high-stress structural applications
🔸 Why Do Customers Choose STKR400?
📌 High Stability – Consistent mechanical properties, suitable for long-term structural loads
📌 Wide Applications – Used in building supports, vehicle frames, machinery equipment
📌 Easy Processing – Weldable, bendable, and cuttable for various manufacturing needs
📌 Comparison of Common Low-Carbon Steel Pipes
Besides STKR400, there are other commonly used low-carbon steel pipes for different applications:
| Material |
Standard |
Yield Strength |
Applications |
| STKR400 |
JIS G3466 |
≥ 245 MPa |
Structural supports, machine frames, steel frameworks |
| A500 Gr.B |
ASTM A500 |
≥ 315 MPa |
North American construction, industrial steel structures |
| STKM11A |
JIS G3445 |
≥ 245 MPa |
Precision machining, automotive parts, electronic enclosures |
| Q235 |
GB/T 700 |
≥ 235 MPa |
General-purpose steel, construction, bridges |
📌 How to Choose the Right Steel Pipe?
When deciding which steel pipe to use, consider your specific needs:
🔸 For structural support (e.g., machine frames, steel structures, building frameworks):
👉 STKR400 is the best choice due to its good ductility, high strength, and affordability
🔸 For high-precision applications (e.g., home appliances, automotive parts, electronic enclosures):
👉 STKM11A or Q195 is better since it has a smooth surface, high dimensional accuracy, and is suitable for precision machining and coating
📌 FAQ: Common Questions
🔸 Is STKR400 suitable for outdoor environments?
👉 Yes! STKR400 can be galvanized (STKR400 Galvanized Round Pipe / STKR400 Galvanized Square Pipe) for enhanced weather resistance, making it ideal for building structures, steel supports, and outdoor machinery.
🔸 What’s the difference between STKR400 and STKM11A?
👉 STKR400 is for structural support (machine frames, building skeletons), while STKM11A is used for precision machining (automotive parts, electronic enclosures, home appliances).
🔸 Does STKR400 have standard sizes?
👉 Yes! Common sizes include 50x50mm, 75x75mm, 100x100mm, with thicknesses ranging from 1.6mm to 6mm, depending on your needs.
🔸 Which industries use STKR400?
👉 STKR400 is widely used in construction, mechanical equipment, bridge supports, and industrial pipelines, especially in applications requiring high strength and excellent weldability.
💡 Want to Learn More About Specifications?
👉 Click Here for Square Pipe Specs
👉 Click Here for Round Pipe Specs
📞 Contact Us
Need STKR400, STKM11A, Q235, A500 Gr.B, or other low-carbon steel pipes? Feel free to contact us anytime!
📩 Line Official Account: @guokai