How does metal casting make use of the different characteristics of liquids and solid

The metal casting make use of the different characteristics of liquids and solid because:

In metal casting they focus on the melting point of the metal, for which they apply the amount of fuel and oxygen to increase the temperature of the boiler above the melting point of the metal, after casting they use molds to give it the desired shape and allow the metal to cool, once it falls below the melting point temperature it acquires the rigidity to be handled, polished or cut, because the particles are more agglomerated than in their liquid state.

Explanation:

Suppose you want to make the door for a car, the selected material is steel, in order to give it the shape of the car, in particular, you have a mold with the shape of the door, in the first instance you proceed to heat the steel to more than 1375 ° C, once the temperature exceeds said degrees the steel goes into a liquid state and allows it to be poured onto the mold (due to the malleability it acquires in this state), once it is deposited in the mold it is allowed to cool, with which the steel particles will join providing rigidity to the metal, on which other works such as polishing may be carried out later.