Calcium-silicon - an alloy that contains by weight  16 % or more of calcium, 45 % or more of silicon, not less than 4 % but less than 14 % of iron and not more than 10 % of any other element; whether or not presented in bulk, packaged in bags or in steel drums, enclosed in steel sheets (or cored wire), or otherwise presented

This chapter defines key ferrous metallurgy terms. 'Pig iron' means iron-carbon alloys not usefully malleable, containing more than 2% carbon by weight and possibly containing other elements within specified limits (e.g. chromium max 10%, manganese max 6%). 'Stainless steel' means alloy steels containing by weight 1.2% or less of carbon and 10.5% or more of chromium, with or without other elements. 'Other alloy steel' means steels not meeting the definition of stainless steel but containing by weight one or more specified elements above minimum thresholds (e.g., aluminium 0.3%, boron 0.0008%, chromium 0.3%, cobalt 0.3%, etc.). The chapter further defines flat-rolled products, bars and rods, hollow profiles, ingots, semi-finished products and specific forms. Iron and steel products are classified by carbon content, alloying elements, and the form of working (hot-rolled, cold-rolled, coated, etc.).

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.