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Semi-finished products are defined in Note 1 (ij) to this Chapter. For the purpose of this Note, the expression subjected to primary hot-rolling 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, pieces roughly shaped by forging, blanks for angles, shapes or sections, and all products obtained by continuous casting.(A) BLOOMS, BILLETS, ROUNDS, SLABS AND SHEET BARS
All these products are obtained by hot-rolling or forging the ingots, puddled bars or pilings classified in heading 72.06. They are semi-finished products intended for further hot-rolling or forging. They are therefore not required to be made exactly to size; the edges are not accurate and the surfaces are often convex or concave and may retain marks caused during the manufacturing processes (e.g., roller marks).
Blooms are usually square in cross-section and are larger than billets; the latter may be either square or rectangular. 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 polygonal cross-section of more than four sides and are chiefly used as intermediate products for the manufacture of seamless steel tubes. They may be distinguished from bars and rods not only by the general characteristics common to the semi-finished products but also by the fact that they are usually supplied in lengths of from 1 to 2 metres and their ends are often cut by blow lamp, which is not the case for bars, which are normally cut more accurately.
Slabs and sheet bars are also rectangular (other than square) in section but they have widths considerably greater than their thicknesses, slabs being thicker than sheet bars. Slabs are therefore usually re-rolled to plates, while sheet bars are normally used to produce sheets or strip. Tinplate bars are a type of sheet bar used in the production of tinplate. With regard to the distinction between slabs and sheet bars and certain plates, see the Explanatory Note to heading 72.08 below. (B) PIECES ROUGHLY SHAPED BY FORGING
These are semi-finished products of rough appearance and large dimensional tolerances, produced from blocks or ingots by the action of power hammers or forging presses. They may take the form of crude recognisable shapes in order that the final article can be fabricated without excessive waste, but the heading covers only those pieces which require considerable further shaping in the forge, press, lathe, etc. The heading would, for example, cover an ingot roughly hammered into the shape of a flattened zig-zag and requiring further shaping to produce a marine crankshaft, but it would not cover a crankshaft forging ready for final machining. The heading similarly excludes drop forgings and pressings produced by forging between matrices since the articles produced by these operations are ready for final machining. (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 girders. (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 products obtained by continuous casting and other products, see paragraph (Ⅲ) of the General Explanatory Note to this Chapter.
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