Abstract: In a rolling mill, a mini block (MBM) is installed between a block mill (BM) and a sizing mill (SM) as a reducer for intermediate rolling. The block mill (BM) is so constructed that it is possible to use both a front group (BM1) and a rear group (BM2) of the rollers, or only the front group by by-passing the rear group with a dummy pass, or to by-pass both the front and the rear groups. The mini block mill (MBM) is shuntable from the pass line. The sizing mill is so constructed with two sets of rollers (SM1, SM2) that either both the sets may be used, or only one of the sets (SM1) may be used and the other (SM2), by-passed. By choosing combinations of use and non-use of the rollers it is possible to produce wires of various diameters from a round rod material of one diameter.