What, in fact, is heavy plate?
Flat steel products of a minimum width of 600 mm are designated in Germany as "plate" or "sheet". Such products with thicknesses of not less than 3 mm are classified as "plate". Flat products with thicknesses of less than 3 mm are referred to as "sheet" or, often, "strip". The DIN standard also previously included the category of "medium plate" for material thicknesses of a minimum of 3 mm up to and including 4.75 mm.
The terms "sheet" and "heavy plate" do not, unfortunately, provide any information on the production process for these flat products. Hot-rolled sheet of up to 3 mm is in most cases produced from hot wide strip, which is rolled up into coils. Up to thicknesses of around 20 mm, plate can also be produced from subdivided hot wide strip (=> strip(heavy)plate), depending on product width and grade of steel. For thicknesses of around 5 mm and above, plate is produced on reversing rolls (=> quarto (heavy) plate). "Quarto" from the Latin for "four", because the so-called "four-high" rolling stand has four rolls - two upper rolls and two lower rolls. The thicknesses of quarto plate supplied by specialised producers such as Dillinger can range up to 400 mm or even more!
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