**6.1. Change of mold size**

The slabs broaden in width, which varies with the operating parameters of steel produced. The statistical data of 76 taper samples of the mold revealed that the change is very small for the taper of the mold. The average change of a one-sided taper was 0.37 mm, and only a few samples had changes of 1~2 mm. The slight change of the taper is due to metering errors, wear, and deformation. Slab broadening is thus independent of the mold size.
