Of an external diameter exceeding 168,3|mm but not exceeding 406,4|mm

1. This Section does not cover: (a) prepared paints, inks or other products with a basis of metallic flakes or powder (headings 3207 to 3210, 3212, 3213 or 3215); (b) ferrocerium or other pyrophoric alloys (heading 3606); (c) headgear or parts thereof of heading 6506 or 6507; (d) umbrella frames or other articles of Chapter 66; (e) goods of Chapter 71 (for example, precious metal alloys, base metal clad with precious metal, imitation jewellery); (f) articles of Section XVI (machinery and mechanical appliances, electrical equipment); (g) assembled railway or tramway track (heading 8608) or other articles of Section XVII (vehicles, aircraft, vessels); (h) instruments or apparatus of Section XVIII, including clock or watch springs; (ij) lead shot prepared for ammunition (heading 9306) or other articles of Section XIX (arms and ammunition); (k) articles of Chapter 94 (furniture, lamps, illuminated signs, prefabricated buildings); (l) articles of Chapter 95 (toys, games, sports requisites); (m) hand sieves, buttons, pens, pencils, pen-holders, monopods, bipods, tripods and similar articles or other articles of Chapter 96; (n) articles of Chapter 97 (works of art). 2. Throughout the Nomenclature, the expression 'parts of general use' means: (a) articles of heading 7307, 7312, 7315, 7317 or 7318 and similar articles of other base metal; (b) springs and leaves for springs, of base metal, other than clock or watch springs (heading 9114); (c) articles of headings 8301, 8302, 8308, 8310 and frames and mirrors, of base metal, of heading 8306. In Chapters 73 to 76 and 78 to 82, references to parts of goods do not include references to parts of general use as defined above. 3. Throughout the Nomenclature, the expression 'base metals' means: iron and steel, copper, nickel, aluminium, lead, zinc, tin, tungsten (wolfram), molybdenum, tantalum, magnesium, cobalt, bismuth, cadmium, titanium, zirconium, antimony, manganese, beryllium, chromium, germanium, vanadium, gallium, hafnium (celtium), indium, niobium (columbium), rhenium and thallium. 4. Throughout the Nomenclature, the term 'cermets' means products containing a microscopic heterogeneous combination of a metallic component and a ceramic component, including sintered metal carbides. 5. Classification of alloys (other than ferro-alloys and master alloys as defined in Chapters 72 and 74): alloys of base metals with each other are to be classified as alloys of the metal which predominates by weight over each of the other metals. Alloys of base metals not elsewhere specified or included are to be classified as articles of the metal predominating by weight.