7 Electric motors for machines, engines not for land vehicles; machines for the production, casting and rolling of metal products in the nature of tundishes, nozzles and parts therefor; oscillating conveyors; extraction machines for the extraction of a cast product, as a billet or a slab, from a casting mold; straighteners, namely, machines used to straighten, i e, conveying a straight direction, a cast product before rolling; travel grates, namely, machines which make a cast product advance stepwise; roller boxes, namely, guide boxes with rolls for guiding a cast product into a rolling stand, and rolling stands with rolls for the rolling of a cast product; oscillating tables, namely, machines to make a cast product advance in an oscillating way; auxiliary wire treatment equipment, namely, descalers; dust and fume collecting and extracting machines; transferring groups, namely, machines for the transfer of a rolled product from of to a rolling line; rolling and finishing trains, namely, groups of rolling stands placed in sequence for the rolling of a cast product; cooling beds, namely, machines for the cooling of a rolled product on which a rolled product moves from one bed to another; coil forming machines, namely, machines for forming coils from a straight rolled product; wire winding machines for forming coils on a conveyer, Mineral treatment plants comprised of sorting and palletizing machines for mineral material; cooling groups, namely, power-operated water or liquid or air sprayers