… 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, … of this heading are obtained, for example, by welding or riveting preformed, unclosed, tubular shapes produced from … can be produced : ‑ longitudinally or spirally in a continuous operation by means of a set of rollers, for …