Of square or rectangular cross-section kg 2

73.06 Other tubes, pi es and hollow profiles (for example, open seam or welded, riveted or similarly dose&, of iron or steel (+). - Line pipe of a kind used for oil or gas pipelines : 7306.1 1 - - Welded, of stainless steel 7306.19 - - Other - Casing and tubing of a kind used in drilling for oil or gas : 7306.21 - - Welded, of stainless steel 7306.29 - - Other 7306.30 - Other, welded, of circular cross-section, of iron or non-alloy steel 7306.40 - Other, welded, of circular cross-section, of stahless steel 7306.50 - Other, welded, of circular cross-section, of other alloy steel - Other, welded, of non-circular cross-section : - - Of square or rectangular cross-section 7306.69 - - Of other non-circular cross-section 7306.90 - Other 7306.61 The provisions of the Explanatory Note to heading 73.05 apply, mutatis mutandis, to the articles of thrs heading. This heading also includes : (1) Tubes and pipes welded by forging, known as butt-welded tubes and pipes. s (2) Tubes and pipes with closed edges, i.e. tubes and lpes, in which the edges touch or cover each other and which are known as open seam tu es. However, products havin an open slit along the whole length are classified as sections in heading 72.16,72.22 or 7i28. (3) Tubes and pipes in which the abutting edges are joined by clipping. Certain longitudinally welded tubes and pipes of this heading have undergone hot or cold drawing or rolling to obtain products having a reduced outside diameter or wall thiclcness and ti ter size tolerances. These cold-working methods also allow different surface finishes to be o tained including polished surfaces, as mentioned in the Explanatory Note to heading 73.04. e See the General Explanatory Note to this Chapter concerning the distinction between tubes and pipes and hollow profiles. This heading includes, in particular, line ipes of a kind used for oil or gas, casing and tubing of a kind used in drillin for oil or as, tu es and pipes suitable for use in boilers, superheaters, heat exchangers, con ensers, feef-water heaters for power stations, galvanised or black tubes {so-called gas tubes) for high or mehum pressure steam or water distribution in buildings, as well as tubes for water or gas street distribution mains. In addition tubes, pipes and hollow profiles are used for the manufacture of parts for automobiles or for machinery, bicycle frames, or tubular structures or building prams, or for other structural uses, construction. Open seam " tubes are used, for examp e, as frames for metal furniture. g f scaffO1dinf " This heading also includes tubes, pi es and hollow rofiles coated with plastics or with glass i S wool combined with bitumen as we as finned or gl led tubes with longtudinal or transversal fins. The heading excludes : (a) Tubes and pipes of cast iron (heading 73.03) and tubes and pipes of iron or steel of heading 73.04 or 73.05. (b) Hollow profiles of cast iron (heading 73.03) and hollow profiles of iron or steel of heading 73.04. (c) Tube or pipe fittings of iron or steel (heading 73.07). (d) Flexible tubing of iron or steel, with or without fittings (including thermostatic bellows and expansionjoints) (heading 83.07). (e) Insulated electrical conduit tubing (heading 85.47). (f) Tubes, pipes and hollow profiles made u into specific identifiable articles, e.g., those repared for use in structures (heading 73.081, tub& sections of central heatmng radiators (ha& 73.221, exhaust manifolds for internal combustion piston engines (heading 84.09), other machinery arts (Section XVI), exhaust boxes (silencers) and exhaust p~ es of vehicles of Chapter 87 heading 87.08 or 87.14), saddle pillars and kames for cycles ?heading 87.14).