By heating large rectangular slabs of steel, typically at a temperature of around 1100°C above their recrystallization temperature in a furnace. Once heated, the slabs are then pressured to flatten them into thin sheets by passing through a series of rolling mills. After rolling, the sheets are cooled using water sprays in a controlled manner to set the desired properties. The resulting hot-rolled sheets manufactured have a rough exterior surface finish typically used in construction, automotive, and other heavy-duty applications.