Notes. 1. In this Chapter the expression "cast iron" applies to products obtained by casting in which iron predominates by weight over each of the other elements and which do not comply with the chemical composition of steel as defined in Note 1 (d) to Chapter 72. 2. In this Chapter the word "wire" means hot or cold-formed products of any cross-sectional shape, of which no cross-sectional dimension exceeds 16 mm.
GENERAL This Chapter covers a certain number of specific articles in headings 73.01 to 73.24, and in headings 73.25 and 73.26 a group of articles not specified or included in Chapter 82 or 83 and not falling in other Chapters of the Nomenclature, of iron (including cast iron as defined in Note 1 to this Chapter) or steel. For the purposes of this Chapter, the expressions "tubes and pipes" and "hollow profiles" have the following meanings hereby assigned to them :
(1) Tubes and pipes Concentric hollow products, of uniform cross-section with only one enclosed void along their whole length, having their inner and outer surfaces of the same form. Steel tubes are mainly of circular, oval, rectangular (including square) cross-sections but in addition may include equilateral triangular and other regular convex polygonal cross-sections. Products of cross-section other than circular, with rounded corners along their whole length, and tubes with upset ends, are also to be considered as tubes. They may be polished, coated, bent (including coiled tubing), threaded and coupled or not, drilled, waisted, expanded, cone shaped or fitted with flanges, collars or rings.
(2) Hollow profiles Hollow products not conforming to the above definition and mainly those not having their inner and outer surfaces of the same form. The General Explanatory Note to Chapter 72 applies, mutatis mutandis, to this Chapter.