Cast iron is a molded alloy of iron, carbon manganese and silicon. It is produced by smelting of raw iron together with coke (coke) and lime in a cupola oven, induction oven or drum oven. Cast iron is very well loaded on pressure, but the tensile strength is not very great with the non-alloyed cast iron types; for tensile construction elements, it is better to use cast steel. In order to achieve very high tensile strength it is possible to add some alloying elements such as nickel, molybdenum and silicon to the melt. The mechanical properties can also be influenced by a heat treatment. Unlike other metals, lamellar cast iron is fairly rigid, not at all flexible, ie fragile at the wrong load. Lamellar cast iron contains about 95% iron. It also contains ± 2.8 – 3.8% carbon, 1 – 3% silicon and 0.3 – 1% manganese. It is a relatively inexpensive material because it is easy to pour and process Ductile cast iron has good mechanical properties. Ductile cast iron with a low silicon content is often used for parts that have to function at very low temperatures (notched impact value). GGG70 nodular cast iron contains 3.40 – 3.85% carbon, 2.30 – 3.10% silicon, 0.10 – 0.30% manganese, maximum 0.02 sulfur and maximum 0.10% phosphorus. To produce a casting, a three-dimensional impression of the final product in a sand mold is required. With the casting process, both semi-finished and finished products can be poured. Casting is often the shortest route to a product. When the required tolerances and surface quality are achieved, further post-processing is not necessary. If these requirements are exceeded, the product still has to be processed after it has been processed. This is often done by machine machining.