Of rectangular (other than square) cross-section

1.- In this Chapter and, in the case of Notes (d), (e) and (f) throughout the Nomenclature, the following expressions have the meanings hereby assigned to them : (a) Pig iron Iron-carbon alloys not usefully malleable, containing more than 2 % by weight of carbon and which may contain by weight one or more other elements within the following limits : - not more than 10 % of chromium - not more than 6 % of manganese - not more than 3 % of phosphorus - not more than 8 % of silicon - a total of not more than 10 % of other elements. (b) Spiegeleisen Iron-carbon alloys containing by weight more than 6 % but not more than 30 % of manganese and otherwise conforming to the specification at (a) above. (c) Ferro-alloys Alloys in pigs, blocks, lumps or similar primary forms, in forms obtained by continuous casting and also in granular or powder forms, whether or not agglomerated, commonly used as an additive in the manufacture of other alloys or as de-oxidants, de-sulphurising agents or for similar uses in ferrous metallurgy and generally not usefully malleable, containing by weight 4 % or more of the element iron and one or more of the following : - more than 10 % of chromium - more than 30 % of manganese - more than 3 % of phosphorus - more than 8 % of silicon - a total of more than 10 % of other elements, excluding carbon, subject to a maximum content of 10 % in the case of copper.