… welded, riveted or similarly closed), having circular cross-sections, the external diameter of which exceeds 406.4 mm, …
Explanatory notes
… welded, riveted or similarly closed), having circular cross-sections, the external diameter of which exceeds 406.4 mm, … unclosed, tubular shapes produced from flat‑rolled products. The tubular shapes can be produced : ‑ … edges are welded without filler metal by flash‑welding, by electrical resistance or induction welding, or by submerged …