Slabs from the blooming or slabbing mills are reheated and rolled by the plate mill into plates for many uses, including boiler plates, ship plates, tank plates, etc.

Plate rolling was described under the making of wrought iron.

The largest plates now rolled are about 145 inches wide. The length depends upon the size of the ingot less the discarded ends.

In rolling plates, care must be taken to keep the upper surface of the plate free of mill scale, which would make a defective surface if rolled into the plate.