Classification of steel tubular poles as parts of structures leads to their inclusion under the residuary tariff heading for structures. Steel tubular poles, made by forming and welding HR coil sections into joined tubular sections that lack a uniform cross section and are further fabricated into identifiable articles for transmission systems, do not qualify as 'other tubes and pipes.' Applying the Explanatory Notes, such tubular poles are complete or incomplete material structures or parts thereof that generally remain in position once installed, and are therefore classifiable under the residuary heading for structures and parts, specifically sub-heading 7308.90 of the Central Excise Tariff Act, 1985.