1. Product Brief
Welded Square Pipe / ERW Square Hollow Section is manufactured by high-frequency electric resistance welding with quality carbon steel strip. Strictly produced under ASTM A500, ASTM A53, EN10219, GB/T6728 standards. Features precise dimension, uniform wall thickness, flat weld seam, good toughness and strong load-bearing capacity. Available in black & hot dip galvanized finish. Widely used for building structure, framework, guardrail, machinery support, shelf and engineering construction.
Key Quality Control: Wall thickness tolerance ≤0.25mm, straightness, squareness, length tolerance and welding quality 100% inspected, fully compliant with international standard requirements.
Size Range: 10×10mm – 500×500mm
Wall Thickness: 1.2mm – 20mm
Standard Length: 6m / 9m / 12m or custom cut
Surface: Black welded, Hot Dip Galvanized (HDG)
Advantages: High welding stability, no crack/no burr, high straightness, easy cutting & bending, excellent structural performance
3. Standard Square Pipe Size & Weight Table (Common Sizes)
Unit: mm / Kg/m
| Square Size | Wall Thickness | Weight(Kg/m) | Square Size | Wall Thickness | Weight(Kg/m) |
| 20×20 | 1.5 | 0.85 | 60×60 | 2.0 | 3.65 |
| 20×20 | 2.0 | 1.10 | 60×60 | 2.5 | 4.50 |
| 25×25 | 1.5 | 1.08 | 60×60 | 3.0 | 5.30 |
| 25×25 | 2.0 | 1.40 | 80×80 | 2.0 | 4.90 |
| 30×30 | 1.5 | 1.32 | 80×80 | 2.5 | 6.10 |
| 30×30 | 2.0 | 1.70 | 80×80 | 3.0 | 7.25 |
| 40×40 | 1.5 | 1.80 | 100×100 | 2.5 | 7.70 |
| 40×40 | 2.0 | 2.35 | 100×100 | 3.0 | 9.20 |
| 40×40 | 2.5 | 2.85 | 100×100 | 4.0 | 12.00 |
| 50×50 | 2.0 | 2.95 | 120×120 | 3.0 | 11.10 |
| 50×50 | 2.5 | 3.65 | 150×150 | 3.0 | 14.00 |
| 50×50 | 3.0 | 4.30 | 150×150 | 4.0 | 18.40 |
4. Production & Testing Standard
Executing Standard: ASTM A500, ASTM A53, EN 10217, EN 10219, GB/T 6728, GB/T 3091
Testing Items: Welding non-destructive test, dimension tolerance check, wall thickness deviation, straightness, tensile & bending test, surface inspection
Custom Service: Special size, special length, galvanized treatment, customized packaging are acceptable
5. Application
Steel structure building, factory frame, construction support, guardrail & fence, machinery equipment base, warehouse shelf, container parts, municipal engineering, scaffolding and other industrial structural projects.