Steel plate is a flat steel plate cast with molten steel and pressed after cooling.It is made of flat plate or steel strip, which can be directly cut into rectangular shape.The steel plates are divided according to the thickness. The thin steel plate is less than 4mm (the thinnest is 0.2mm), the thick steel plate is 4 ~ 60mm, and the extra thick steel plate is 60 ~ 115mm.Steel plates are divided into hot rolled and cold rolled according to rolling.The width of the sheet is 500 ~ 1500 mm; The width of the thickness is 600 ~ 3000 mm. Thin plates are divided into ordinary steel, high-quality steel, alloy steel, spring steel, stainless steel, tool steel, heat-resistant steel, bearing steel, silicon steel and industrial pure iron thin plates; According to professional use, there are oil barrel plate, enamel plate, bulletproof plate, etc; According to the surface coating, there are galvanized sheet, tinned sheet, lead plated sheet, plastic composite steel plate, etc.