Square Steel Pipe (SHS) - China Suppliers & Factory for High-Quality Square Hollow Sections
Detailed Description of Square Steel Pipe (SHS)
Square Hollow Section (SHS) is a structural pipe manufactured by high frequency resistance welding (ERW) or thermoforming process. ERW process cold bends the steel strip into a round pipe and welds it, then presses the square through the calibrating roll, and heat treats it to eliminate the stress after welding, so the dimensional accuracy reaches ±0.5mm. thermoforming process heats the round pipe billet to 900-950°C and expands the square hydraulically, so it realizes the homogeneous structure without weld seams, and the uniformity of the wall thickness is more than 95%. The closed section provides excellent torsional resistance. High strength and light weight (HSLA steel strength ≥355MPa), right-angled edges are easy to weld around the whole circumference, which is the preferred solution for building frames, machinery trusses and other load-bearing structures.
Key Parameters for Square Steel Pipe
| Parameter | Details |
|---|---|
| Manufacturing Process | ERW (Cold Formed or Hot Formed), Seamless (less common for SHS) |
| Standards | ASTM A500 (Gr. A, B, C, D), EN10219 (S235JRH, S275J0H, S275J2H, S355J0H, S355J2H, S355K2H), EN10210 (S235JRH, S275J0H, S275J2H, S355J0H, S355J2H, S355NH, S355NLH), JIS G3466 (STKR400, STKR490), AS/NZS 1163 (C250, C350, C450) |
| Steel Grade | Q195, Q235, Q345 (Chinese Standards); Gr. A, B, C, D (ASTM A500); S235, S275, S355 (EN Standards); STKR400, STKR490 (JIS) |
| Size (Side x Side) | 15x15mm to 500x500mm (larger sizes may be available) |
| Wall Thickness (WT) | 0.8mm to 25mm (varies with size and standard) |
| Length | Usually 6m or 12m; can be customized (e.g., 5.8m for container loading) |
| Corner Radius | Typically 2T to 3T (T = Wall Thickness), varies by standard |
| Surface Treatment | Black (bare/self-color), Oiled, Galvanized (Hot-dip or Pre-galvanized), Painted/Powder Coated |
| Inspection | Dimensional Check, Tensile Test, Yield Strength, Elongation, Weld Test (for ERW), Chemical Analysis |
Frequently Asked Questions
QWhat is a Square Hollow Section (SHS)?
A Square Hollow Section (SHS) is a structural steel pipe with a square profile. It is manufactured using either High-Frequency Resistance Welding (ERW) or thermoforming processes, providing a uniform, high-strength structure with excellent torsional resistance.
QWhat is the difference between ERW and thermoforming for SHS?
The ERW process cold bends a steel strip into a round pipe, welds it, shapes it into a square, and heat treats it to remove stress (accuracy up to ±0.5mm). The thermoforming process heats the billet to 900-950°C and expands it hydraulically, creating a seamless structure with over 95% wall thickness uniformity.
QWhat sizing options are available for square steel pipes?
Square steel pipes typically range in side dimensions from 15x15mm to 500x500mm, with wall thicknesses ranging from 0.8mm to 25mm. Standard lengths are usually 6m or 12m, though custom lengths (like 5.8m for containers) can be fabricated.
QWhich international standards apply to Square Hollow Sections?
SHS is manufactured to various global standards including ASTM A500 (American), EN10219 & EN10210 (European), JIS G3466 (Japanese), and AS/NZS 1163 (Australian/New Zealand).
QWhat surface treatments can be applied to square steel pipes?
To prevent corrosion and improve durability, square steel pipes can be finished with several surface treatments including self-color black (bare), oiled, hot-dip or pre-galvanized, and painted or powder-coated finishes.
QWhy is SHS preferred for structural load-bearing applications?
SHS is highly preferred due to its closed geometric section which provides superior torsional resistance. Additionally, its high strength-to-weight ratio (HSLA steel strength ≥355MPa) and right-angled edges make it exceptionally easy to weld around the entire circumference for building frames and machinery trusses.