SHANDONG SHOUYA STEEL CO., LTD.
| Equivalent Standard | GB/T 6728 / GB/T 3094 / ASTM A500 / EN 10219 |
| Size Tolerance | ±1% / ±0.5 mm |
| Delivery Time | 15-30 days |
| Tensile Strength | 375–500 MPa (Q235B) / 490–675 MPa (Q345B) |
| Surface Finish | Black / Bare / Oiled / Painted |
| Length | 6 m / 12 m / Custom |
| Payment Terms | T/T |
| Manufacturing Process | Welded (ERW / HFW) |
| Corner Radius | Sharp / Rounded |
| Wall Thickness Range | 1.5–20 mm |
| Material Grade | Q235B / Q345B |
| WT Tolerance | ±10% |
| Packaging Details | Standard Export Packing |
| Heat Treatment | As-rolled / Normalized |
| Outer Size Range | 20×20 – 400×400 mm |
| Yield Strength | ≥235 MPa (Q235B) / ≥345 MPa (Q345B) |
| Chemical Composition | C, Si, Mn, P, S (per GB/T 700 / GB/T 1591) |
| Shape | Square Hollow Section (SHS) |
| Supply Ability | 50,0000 tons per year |
| Weld Type | ERW / HFW / Square tube |
| Seam | Longitudinal seam |
| Straightness | ≤1.5 mm/m |
| Material Category | Carbon Structural Steel |
| Model Number | Q235 Q345 ASTM A36 / A572 Gr.50 | EN S235JR / S355JR |
| Brand Name | Shouya |
| Place of Origin | China |
| Certification | CE, EN |
View Detail Information
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Product Specification
| Equivalent Standard | GB/T 6728 / GB/T 3094 / ASTM A500 / EN 10219 | Size Tolerance | ±1% / ±0.5 mm |
| Delivery Time | 15-30 days | Tensile Strength | 375–500 MPa (Q235B) / 490–675 MPa (Q345B) |
| Surface Finish | Black / Bare / Oiled / Painted | Length | 6 m / 12 m / Custom |
| Payment Terms | T/T | Manufacturing Process | Welded (ERW / HFW) |
| Corner Radius | Sharp / Rounded | Wall Thickness Range | 1.5–20 mm |
| Material Grade | Q235B / Q345B | WT Tolerance | ±10% |
| Packaging Details | Standard Export Packing | Heat Treatment | As-rolled / Normalized |
| Outer Size Range | 20×20 – 400×400 mm | Yield Strength | ≥235 MPa (Q235B) / ≥345 MPa (Q345B) |
| Chemical Composition | C, Si, Mn, P, S (per GB/T 700 / GB/T 1591) | Shape | Square Hollow Section (SHS) |
| Supply Ability | 50,0000 tons per year | Weld Type | ERW / HFW / Square tube |
| Seam | Longitudinal seam | Straightness | ≤1.5 mm/m |
| Material Category | Carbon Structural Steel | Model Number | Q235 Q345 ASTM A36 / A572 Gr.50 | EN S235JR / S355JR |
| Brand Name | Shouya | Place of Origin | China |
| Certification | CE, EN | ||
| High Light | Square Hollow Section Tube Q235B ，Square Hollow Section Tube Q345B ，Construction SHS Steel Tube | ||
Black Square Hollow Section (SHS) ERW Welded Steel Tube for Construction
Q235B / Q345B | Equivalent to ASTM A36 / A572 Gr.50 | EN S235JR / S355JR
Product Overview
Black Square Hollow Section (SHS) is an ERW welded steel tube supplied in uncoated, mill-finish condition. The term "Black" refers to the natural oxidized surface retained from the steel mill — it is not a painted or coated product. This is the base material from which all galvanized and painted square tubes are made.
The tube is produced by the ERW (Electric Resistance Welding) process, in which steel strip is cold-formed into a square section and the longitudinal seam is welded using high-frequency current. This is the mainstream production method for square hollow sections, offering high efficiency, consistent wall thickness, and precise dimensional accuracy.
Material Grades & International Equivalents
| Chinese Grade | Min. Yield Strength | ASTM Equivalent | EN Equivalent | JIS Equivalent |
|---|---|---|---|---|
| Q235B | 235 MPa | A36 / A283 Gr.D | S235JR | SS400 / SM400A |
| Q345B | 345 MPa | A572 Gr.50 | S355JR | SM490A / SS490 |
Notes on Equivalency:
These grades are approximate equivalents, not exact substitutes. Chemical composition and mechanical properties may differ slightly between standards. For export orders, mill test certificates can be issued showing the corresponding international grade designation upon request.
Surface Condition
Supplied in Black (uncoated) condition, typically with a light anti-rust oil applied at the mill for protection during transport and short-term storage. This surface is ideal for:
Components to be painted, powder-coated, or hot-dip galvanized after fabrication
Indoor structural frames, machinery bases, and welded assemblies
Heavy fabrication where anti-corrosion treatment is applied after welding
Note: Black SHS is not intended for direct outdoor or moisture-exposed service. For outdoor applications, hot-dip galvanizing or painting after welding is recommended.
Size Range (Typical)
| Item | Range |
|---|---|
| Square Size | 20*20 mm — 500*500 mm |
| Wall Thickness | 0.5 mm — 20 mm |
| Length | 5.8 m / 6 m, or customized |
Standards
Manufactured to EN 10219, ASTM A500, GB/T 6728, or equivalent standards. Mill test certificates are available upon request.
Typical Applications
Indoor building structural frames
Machinery manufacturing and equipment bases
Conveyor line supports and welded structural components
Semi-finished parts requiring subsequent painting or galvanizing
General construction and fabrication projects
Why Choose Black SHS ERW Welded Tube
Cost-effective — lower unit price than galvanized or painted tube
Fabrication-friendly — excellent weldability for cutting, drilling, and joining
Versatile — suitable for a wide range of structural and mechanical applications
Customizable — sizes, wall thicknesses, and lengths can be produced to order
Company Details
Business Type:
Manufacturer,Agent,Exporter,Trading Company
Year Established:
2009
Total Annual:
200000000-230000000
Employee Number:
150~170
Ecer Certification：
Verified Supplier
Shandong Shouya Steel Co., Ltd. Welcome to Shandong Shouya Steel Co., Ltd., a professional steel foreign trade and steel solution provider based in Shandong, China. Founded in 2009, we leverage Shandong’s steel industrial cluster advantages and boast more than ten years of experience in... Shandong Shouya Steel Co., Ltd. Welcome to Shandong Shouya Steel Co., Ltd., a professional steel foreign trade and steel solution provider based in Shandong, China. Founded in 2009, we leverage Shandong’s steel industrial cluster advantages and boast more than ten years of experience in...
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