A flat steel plate made by pouring molten steel, cooling it, and pressing it. It is flat, rectangular, and can be directly rolled or cut from wide steel strips. Steel plates are divided by thickness, with thin steel plates<4 millimeters (thinnest 0.2 millimeters), medium thick steel plates ranging from 4 to 60 millimeters, and extra thick steel plates ranging from 60 to 115 millimeters. Steel plates are divided into hot-rolled and cold-rolled according to rolling.