Of rectangular (including square) cross-section, the width

72.07 - Semi-fmished products of iron or non-alloy steel. 7207.1 1 7207.12 7207.19 7207.20 - Containing by weight less than 0.25 % of carbon : - - Of rectangular (including square) cross-section, the width measuring less than twice the thickness - - Other, of rectangular (other than square) cross-section - - Other - Containing by weight 0.25 % or more of carbon Semi-finished products are defined in Note 1 (i') to this Chapter. For the purpose of this Note, the expression " subjected to primary hot-rol ing " applies to products which have been subjected to a rolling operation which has given them a rough appearance. The heading covers blooms, billets, rounds, slabs, sheet bars, ieces roughly shaped by forging, blanks for angles, shapes or sections, and all products obtaine by continuous casting. B (A) BLOOMS, BILLETS, ROUNDS, SLABS AND SHEET BARS All these products are obtained by hot-rolling or forging the ingots, uddled bars or ilings classified in heading 72.06. They are semi-finshed products intended or fiuther hot-rol!lng or for ing. They are therefore not required to be made exactly to size; the edges are not accurate an the surfaces are often convex or concave and may retain marks caused during the manufacturing processes (e.g., roller marks). P f Blooms are usual1 square in cross-section and are larger than billets; the latter may be either square or rectangdar. Both are used for re-rolling to bars, rods, angles, shapes and sections, or for the manufacture of forgings. Rounds are of circular or of pol gonal cross-section of more than four sides and are chiefly used as intermediate products or the manufacture of seamless steel tubes. They may be bars and rods not only b the general characteristics common to the but also by the fact that t ey are usually supplied in lengths of from 1 to are often cut by blow lamp, which is not the case for bars, which are normally cut more accurately. fY i!, Slabs and sheet bars are also rectangular (other than square) in section but they have widths considerably eater than their thicknesses, slabs being thicker than sheet bars. Slabs are therefore usua ly re-rolled to plates, while sheet bars are normall used to roduce sheets or strip. Tinplate bars are a type of sheet bar used in the production o tinplate. ith regard to the distinction between slabs and sheet bars and certain plates, see the Explanatory Note to heading 72.08 below. P P & (B) PIECES ROUGHLY SHAPED BY FORGING These are semi-finished products of rough a pearance and large dimensional tolerances, produced from blocks or ingots by the action o power hammers or forgin presses. They may take the form of crude recognisable shapes in order that the final artic e can be fabricated without excessive waste, but the heading covers only those pieces which re uire considerable further shaping in the forge, press, lathe, etc. The headin would, for examp e, cover an ingot roughly hammered into the sha e of a flattened zig-zag an requiring further shaping to produce a marine crankshaft, but it wou d not cover a crankshaft forging ready for final m a c k n g . The heading similarly excludes drop forgings and pressin s roduced by forging between matrices since the articles produced by these operations are rea y or final machining. ? P f f f! (C) BLANKS FOR ANGLES, SHAPES OR SECTIONS Blanks for angles, shapes or sections may have a cross-section of complex form adapted to that of the finished product and the corresponding rolling process. The heading covers, for example, blanks for wide-flanged beams or guders. (D) SEMI-FINISHED PRODUCTS OBTAINED BY CONTINUOUS CASTING This group covers all semi-finished products of iron or non-alloy steel, under any form, obtained by continuous casting. In this process steel is conveyed from the ladle in a distributor which feeds the different casting flow lines. These flow lines include : (a) A mould, without bottom, with its cooling devices; (b) Outside the mould a system for atomising water in order to cool the cast metal; (c) A group of conveyor rollers allowing the regular extraction of the solidified metal; and (d) A system of cutting-off machines, followed by an evacuation device. For the criteria to differentiate between roducts obtained by continuous casting and other products, see paragraph (III) of the Generaf'Explanatory Note to this Chapter.