Square tube
Large-section band for portal frames, plant structures and heavy transport equipment. Rolled on the 400 line, wall 8–16 mm.
Cross-section
Outside dimension 350×350 mm, wall 9.0–14.0 mm, corner radius 2–3 × wall.
Specification
| Section | 350×350 mm |
|---|---|
| Wall range | 9.0 – 14.0 mm |
| Weight / m | 96.37 – 147.71 kg |
| Length | 6 / 9 / 12 m, or cut to length |
| Production line | 400 |
| Standards | GB/T 6728 · GB/T 3094 · EN 10219 · ASTM A500 |
| Tolerance | Wall ±10 % · squareness 90° ±1° · straightness ≤0.15 % L |
| Certificate | EN 10204 3.1 mill certificate with every heat |
Weights assume 7.85 g/cm³. Made to order — 10–25 days.
Grades
Other grades and equivalent EN / ASTM designations are quoted on request. Tell us the standard, not just the grade — we will match it.
Applications
Cut to length and drilled to your DXF, delivered as a bolt-on part.
Mill certificate traceable to the heat, so your inspector signs off without a second trip.
Consistent wall and squareness batch to batch — welding fixtures stay in tolerance.
FAQ
350×350 is made to order on the 400 line, typically 10–25 days depending on grade and coating.
Between 96.37 and 147.71 kg/m across the 9.0–14.0 mm wall range (theoretical, 7.85 g/cm³).
Q235B, Q355B–E, Q420B, 510L/610L/700L, 500TM/700TM and SPA-H; other grades on request.
Nearby sizes
Send the drawing or the standard — quote within 48 hours.